AS1110
Constant-Current, 16-Channel LED Driver with Diagnostics
www.austriamicrosystems.com/LED-Driver-ICs/AS1110 Revision 1.05 1 - 24
Datasheet
1 General Description
The AS1110 is designed to drive up to 16 LEDs through
a fast serial interface and features 16 outp ut constant
current drivers and an on-chip diagnostic read-back
function.
The high clock-frequency (up to 50MHz), adjustable out-
put current, and flexible serial interface makes th e
device perfectly suited for high-vo l ume transmission
applications.
Output current is adjustable (up to 100mA/channel )
using an external resistor (REXT).
The serial interface with Schmitt trigger inputs includes
an integrated shift register. Additionally, an internal data
register stores the currently displayed data.
The device features integrated diagnostics for over-
temperature, open-LED, and shorted-LED conditions.
Integrated registers store glob al fault status information
during load as well as the detailed te mperature/open-
LED/shorted-LED diagnostics results.
The AS1110 also features a low-current diagnostic
mode to minimize display flicker during fault testing.
The AS1110 is available in a 24-pin SSOP and the 28-
pin QFN (5x5mm) package.
Figure 1. Main Diagram and Pin Assi gnments
2 Key Features
! 16 Constant-Current Output Channels
! Excellent Output Current Accuracy
- Between Channels: <±3%
- Between Devices: <±3%
! Output Current Per Channel: 0.5mA to 100mA
! Controlled In-Rush Curren t
! Over-Temperature, Open-LED, Shorted-LED
Diagnostic Functions
! Low-Current Test Mode
! Global Fault Monitoring
! Low Shutdown Mode Current: 10µA
! Fast Serial Interface: 50MHz
! Cascaded Configuration
! Extremely Fast Output Drivers Suitable for PWM
! 24-pin SSOP and 28-pin QFN (5x5mm) Package
3 Applications
The device is ideal for fixed- or slow-rolling displays
using static or multiplexed LED matrix and dimming
functions, large LED matrix displays, mixed LED display
and switch monitoring, displays in elevators, public
transports (underground, trains, buses, taxis, airplanes,
etc.), large displays in stadiums and public areas, price
indicators in retail stores, promotional panels, bar-graph
displays, industrial controller displays, white good pan-
els, emergency light indicators, and traffic signs.
AS1110
SDI SDO
CLK LD OEN REXT
+VLED
OUTN3
OUTN4
OUTN5
OUTN6
OUTN7
OUTN8
OUTN9
OUTN10
GND VDD
OUTN0
OUTN1
OUTN2
OUTN11
OUTN12
OUTN13
OUTN14
OUTN15
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AS1110
Datasheet
Contents
1 General Description ................................................................................................................................ 1
2 Key Features .......................................................................................................................................... 1
3 Applications ............................................................................................................................................ 1
4 Pinout ..................................................................................................................................................... 3
Pin Assignments ..................... ... ... .................... .. .................... ... ................... ... ... .................................................... 3
Pin Descriptions ........................... ... ................... ... .................... ... .. .................... ... .......... ....................................... 3
5 Absolute Maximum Ratings .................................................................................................................... 4
6 Electrical Characteristics ........................................................................................................................ 5
Switching Characteristics ....................................................................................................................................... 6
7 Typical Operating Characteristics ........................................................................................................... 7
8 Detailed Description ............................................................................................................................... 8
Serial Interface ....................................................................................................................................................... 9
Timing Diagrams .................................................................................................................................................... 9
Error-Detection Mode ........................................................................................................................................... 11
Global Error Mode ................................................................................................................................................ 11
Error Detection Functions ..................................................................................................................................... 12
Open-LED Detection ..... .. .................... ... ................... ... .................... ... .. .................... ... ................................. 12
Shorted-LED ................................................................................................................................................. 12
Overtemperature ........................................................................................................................................... 12
Detailed Error Reports .......................................................................................................................................... 13
Detailed Temperature Warning Report .......... ... ... ......................................................................................... 13
Detailed Open-LED Error Report .................................................................................................................. 14
Detailed Shorted-LED Error Report .... ... ... ....................................... ... .. ........................................................ 15
Low-Current Diagnostic Mode ....................................................................................................................... 15
Shutdown Mode .................................................................................................................................................... 16
9 Application Information ......................................................................................................................... 17
Error Detection ..................................................................................................................................................... 17
Error Detection On-The-Fly ........................................................................................................................... 17
Error Detection with Low-Current Diagnosis Mode ....................................................................................... 17
Cascading Devices ............................................................................................................................................... 18
Constant Current .................................................................................................................................................. 19
Adjusting Output Current ...................................................................................................................................... 19
Package Power Dissipation .................................................................................................................................. 19
Delayed Outputs ..................... ... ... .................... .. .................... ... ................... ... ... .................................................. 19
Switching-Noise Reduction .................................................................. ... ... .......................................................... 19
Load Supply Voltage ............................................................................................................................................. 19
10 Package Drawings and Markings ....................................................................................................... 21
11 Ordering Information ........................................................................................................................... 23
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AS1110
Datasheet - Pin o u t
4 Pinout
Pin Assignments
Figure 2. Pin Assignments (Top View)
Pin Descriptions
Table 1. Pin Descriptions
Pin Number Pin Name Description
SSOP QFN
1 24:27 GND Ground
228 SDI
Serial Data Input
31 CLK
Serial Data Clock. The rising edge of the CLK signal is used to clock data
into and out of the AS1 110 shift register . In error mode, the rising edge of the
CLK signal is used to switch error modes.
42 LD
Serial Data Load
5:20 3:10
12:19 OUTN0:15 Output Current Drivers. These pins are used as LED drivers or for input
sense for diagnostic modes. Data is transferred to the data register at the
rising edge of these pins.
21 20 OEN
Output Enable. The active-low pin OEN signal can always enable output
drivers to sink current independent of the AS1110 mode.
0 = Output drivers are enabled.
1 = Output drivers are disabled.
22 21 SDO
Serial Data Output. In normal mode SDO is latched out 8.5 clock cycles
after SDI is latched in.
In global error detection mode this pin indicates the occurre nce of a global
error.
0 = Global error mode returned an error.
1 = No errors.
23 22 REXT External Resistor Connection. This pin connects through the external
resistor (REXT) to GND, to setup the load current.
24 23 VDD Positive Supply Voltage
-11 N/C
Not connected
1
GND
AS1110
24-pin SSOP
24
VDD
2
SDI
3
CLK
4
LD
5
OUTN0
23
REXT
22
SDO
21
OEN
17
OUTN12
8
OUTN3
7
OUTN2
6
OUTN1
20
OUTN15
19
OUTN14
18
OUTN13
9
OUTN4
13
OUTN8
12
OUTN7
11
OUTN6
10
OUTN5
16
OUTN11
15
OUTN10
14
OUTN9
SDO
OUTN7
OUTN5
10
21
OUTN13
17
8
CLK 1
OUTN0 3
OUTN4 7
AS1110
28-pin QFN 5x5
OUTN2 5
OUTN8
12
OUTN10
14
OUTN11
15
OUTN15
19
OEN
20
OUTN14
18
OUTN12
16
LD 2
OUTN1 4
OUTN3 6
OUTN9
13
N/C
11
OUTN6
9
GND
SDI
2628
GND
24
REXT
22
VDD
23
GND
25
GND
27
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AS1110
Datasheet - Ab so lu te Ma xi mu m R at in gs
5 Absolute Maximum Ratings
Stresses beyond those list ed in Table 2 may cause permanent damage to the device. These are stress ratings only,
and functional operation of the device at these or any other conditions beyond those indicated in Sectio n 6 Electrical
Characteristics on page 5 is not implied. Exposure to absolute maximum rating conditions for extended periods may
affect device reliability.
Table 2. Absolute Maximum Ratings
Parameter Min Max Units Comments
VDD to GND 0 7 V
Input Voltage -0.4 VDD
+0.4 V
Output Voltage -0.4 15 V
GND Pin Current 2000 mA 24-pin SSOP package
2800 mA 28-pin QFN (5x5mm) package
Thermal Resistance ΘJA 88 ºC/W on PCB, 24-pin SSOP package
23 ºC/W on PCB, 28-pin QFN (5x5mm) package
Ambient Temperature -40 +85 ºC
Storage Temperature -55 150 ºC
Humidity 5 86 % Non-condensing
Electrostatic
Discharge Digital Outputs 2 kV Norm: MIL 833 E method 3015
All Other Pins 2
Latch-Up Immunity -100 -
(INOM x 0.5) +100 +
INOM mA EIA/JESD78
Package Body Temperature +260 ºC
The reflow peak soldering temp e rature (body
temperature) specified is in accordance with
IPC/JEDEC J-STD-020D “Moisture/Reflow
Sensitivity Classification for Non-Hermetic Solid
State Surface Mount Devices”.
The lead finish for Pb-free leaded packages is
matte tin (100% Sn).
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AS1110
Datasheet - Ele c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
VDD = +3.0V to +5.5 V, TAMB = -40°C to +85ºC (unless otherwise specified).
Table 3. Electrical Characteristics
Symbol Parameter Condition Min Typ Max Unit
VDD Supply Voltage 3.0 5.5 V
VDS Output Voltage OUTN0:15 0 15.0 V
IOUT
Output Current
OUTN0:15, VDD = 5V (see Figure 7) 0.5 100
mA
IOH SDO -1.0
IOL SDO 1.0
VIH Input Voltage High Level CLK, OEN, LD, SDI
0.7 x
VDD VDD +
0.3 V
VIL Low Level -0.3 0.3 x
VDD
IDS(OFF) Output Leakage Current OEN = 1, VDS = 15.0V 0.5 µA
VOL Output
Voltage SDO IOL = +1.0mA 0.4 V
VOH IOH = -1.0mA VDD -
0.4V
IAV(LC1) Device-to-Device Average Output
Current from OUTN0 to OUTN15 VDS = 0.5V, VDD = Const.,
REXT = 744Ω24.5 26 mA
ΔIAV(LC1) Current Skew
(Between Channels) VDS ≥ 0.5V, VDD = Const.,
REXT = 744Ω ±1 ±3 %
IAV(LC2) Device-to-Device Average Output
Current from OUTN0 to OUTN15 VDS = 0.6V, VDD > 3.3V,
REXT = 372Ω49.50 51.55 mA
ΔIAV(LC2) Current Skew
(Between Channels) VDS ≥ 0.6V, VDD = Const.,
REXT = 372Ω ±1 ±2 %
IAV(LC3) Device-to-Device Average Output
Current from OUTN0 to OUTN15 VDS = 0.8V, VDD = 5.0V,
REXT = 186Ω 98 104 mA
ΔIAV(LC3) Current Skew
(Between Channels) VDS ≥ 0.8V, VDD = Const.,
REXT = 186Ω ±1 ±2 %
ILC Low-Current Diagnosis Mode VDS = 0.8V, VDD = 5.0V 0.4 0.6 0.8 mA
IPD Power Down Supply Current VDS = 0.8V, VDD = 5.0V,
REXT = 372Ω, OUTN0:15 = On 10 20 µA
%/ΔVDS Output Current vs.
Output Voltage Regulation VDS within 1.0 and 3.0V ±0.1 %/V
%/ΔVDD Output Current vs.
Supply Voltage Regulation VDD within 3.0 and 5.0V ±1 %/V
RIN(UP) Pullup Resistance OEN 250 500 800 kΩ
RIN(DOWN) Pulldown Resistance LD 250 500 800 kΩ
VTHL Error Detection Threshold Voltage 0.25 0.3 0.45 V
VTHH Error Detection Threshold Voltage VDD = 3.0V 1.2 1.3 1.4 V
VDD = 5.0V 2.0 2.2 2.4
TOV1 Overtemperature Threshold Flag 150 º C
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AS1110
Datasheet - Ele c t r i c a l C h a r a c t e r i s t i c s
Switching Characteristics
VDD = 3.0 to 5.5V, VDS = 0.8V, VIH = VDD, VIL = GND, REXT = 372Ω, VLOAD = 4.0V, RLOAD = 64Ω, CLOAD = 10pF; guar-
anteed by design.
* If multiple AS1110 devices are cascaded and tr or tf is large, it may be critical to achieve the timing required for data
transfer between two cascaded LED drivers.
IDD(OFF)0
Supply
Current
Off
REXT = Open‚ OUTN0:15 = Off 2.7 6
mA
IDD(OFF)1 REXT = 744Ω‚ OUTN0:15 = Off 4.3 8
IDD(OFF)2 REXT = 372Ω‚ OUTN0:15 = Off 5.4 9
IDD(OFF)3 REXT = 186Ω, OUTN0:15 = Off 9.3 13
IDD(ON)1
On
REXT = 744Ω‚ OUTN0:15 = On 6.2 11
IDD(ON)2 REXT = 372Ω‚ OUTN0:15 = On 10.5 15
IDD(ON)3 REXT = 186Ω‚ OUTN0:15 = On 19.5 26
Table 4. Switching Characteristics for VDD = 5V
Symbol Parameter Conditions Min Typ Max Unit
tP1 Propagation Delay Time (Without
Staggered Output Delay)
CLK - SDO 5 10 nstP2 LD - OUTNn 100 200
tP3 OEN - OUTNn 100 200
tP4 Propagation Delay Time 10 ns
tW(CLK) Pulse Width CLK 15 nstW(L) LD 15
tW(OE) OEN (@IOUT < 60mA) 200
tR *CLK Rise Time 500 ns
tF *CLK Fall Time 500 ns
tOR Output Rise Time of VOUT (Turn Off) 100 200 ns
tOF Output Fall Time of VOUT (Turn On) 100 300 ns
tSU(D) Setup Time for SDI 5 ns
tH(D) Hold Time for SDI 5 ns
tSU(L) Setup Time for LD 5 ns
tH(L) Hold Time for LD 5 ns
tTESTING OEN Time for Error Detection 2000 ns
tSTAG Staggered Output Delay 20 40 ns
tSU(OE) Output Enable Setup Time 20 ns
tGSW(ERROR) Global Error Switching Setup Time 10 ns
tSU(ERROR) Global Error Detection Setup Time 10 ns
tP(I/O) Prop agation Delay Global Error Flag 5 ns
tSW(ERROR) Switching Time Global Error Flag 10 ns
fCLK Maximum Clock Frequency
(Cascade Operation) 30 50 MHz
tP3,ON Low-Current Test Mode
Propagation Delay Time Turn ON 3 5 µs
tP3,OFF Turn OFF 0.05 0.1 µs
tREXT2,1 External Resistor Reaction Time Change from REXT1 = 372Ω,
IOUT1 = 50.52mA to REXT2 =
37.2kΩ, IOUT2 < 1mA 0.5 1 µs
tREXT2,1 External Resistor Reaction Time Change from REXT1 = 37.2kΩ,
IOUT1 = 0.5mA to REXT2 =
372Ω, IOUT2 > 25mA 0.5 1 µs
Table 3. Electrical Characte ristics (Continued)
Symbol Parameter Condition Min Typ Max Unit
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AS1110
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
Figure 3. Output Current vs. REXT, Figure 4. Relative Output Current Error vs. VDD,
VDD = 5V; VDS = 0.8V, TAMB = 25°C Iout/Iout@VDD=5V - 1, TAMB = 25°C
Figure 5. Output Current vs. VDS; Figure 6. Output Current vs. VDS;
VDD = 5V, TAMB = 25°C VDD = 5V, TAMB = 25°C
Figure 7. Output Current vs. VDD
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
33.544.555.5
VDD (V)
Relat iv e Out put Current E r r or (%)
.
REXT = 744Ω;
VDS = 0.5V
REXT = 372Ω;
VDS = 0.6V
REXT = 186Ω;
VDS = 0.8V
1
10
100
100 1000 10000
RE XT ( )
IOUT (mA) .
Ω
0
20
40
60
80
100
120
0 0.2 0.4 0.6 0.8 1 1.2 1.4
VDS (V)
IOUT (mA) .
0
20
40
60
80
100
120
03691215
VDS (V)
IOUT (mA) .
REXT = 251Ω
REXT = 372Ω
REXT = 186Ω
REXT = 744Ω
REXT = 251Ω
REXT = 372Ω
REXT = 186Ω
REXT = 744Ω
0
20
40
60
80
100
120
3 3.5 4 4.5 5 5.5
VDD (V)
IOUT (mA) .
VDS = 0.8V
VDS = 0.7V
VDS = 0.6V
VDS = 0.5V
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AS1110
Datasheet - D et a i l e d De s c r i p t i o n
8 Detailed Description
The AS1110 is designed to drive up to 16 LEDs through a fast serial interface and 16 constant-current output drivers.
Furthermore, the AS1110 provides diagnostics for detecting open- or shorted-LEDs, as well as over-temperature con-
ditions for LED display systems, especially LED traffic sign applications.
The AS1110 contains an 16-bit shift register and an 16-bit data register , which convert serial input data into parallel out-
put format. At AS1110 output stages, sixteen regulated current sinks are designed to provide uniform and constant cur-
rent with excellent matching between ports for driving LEDs within a wide range of forward voltage variations. External
output current is adjustable from 0.5 to 100mA using an external resistor for flexibility in controlling the brightness
intensity of LEDs. The AS1110 guarantees to endure 15V maximum at the outputs.
The serial interface is capable of operating at a minimum of 30 MHz, satisfying the requireme nts of high-volume data
transmission.
Using a multiplexed input/output technique, the AS1110 adds additional functionality to pins SDO, LD and OEN. These
pins provide highly useful functions (open- and shorted-LED detection, over-temperature detection), thus reducing pin
count. Over-temperature detection will work on-the-run, whereas the open- and shorted-LED detectio n can be used
on-the-run or in low-current di agnostic mode (see page 15).
Figure 8. AS1110 - Block Diagram
AS1110
REXT
OEN
CLK
SDI
LD
Current
Generators
Detailed
Error
Detection
16-Bit Data
Register
16-Bit Shift
Register
Temperature
Detection 16-Bit Open
Detection &
Error Register
16-Bit Short
Detection &
Error Register
Global
Error
Detection
SDO
Indicates 16 Bit Path
Control Logic
+VLED
OUTN0
OUTN1
OUTN2
OUTN3
OUTN4
OUTN5
OUTN6
OUTN7
OUTN8
OUTN9
OUTN10
OUTN11
OUTN12
OUTN13
OUTN14
OUTN15
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AS1110
Datasheet - D et a i l e d De s c r i p t i o n
Serial Interface
Data accesses are made serially via pins SDI and SDO. At each CLK rising edge, th e signal present at pin SDI is
shifted into the first bit of the internal shift register and the other bits are shifted ahead of the first bit. The MSB is the
first bit to be clocked in. In error-detection mode the shift register will latch-in the corresponding error data of tempera-
ture-, open-, and short-error register with each falling edge of LD.
The 16-bit data register will latch the data of the shift register at each rising edge of LD. This data is then used to drive
the current generator output drivers to switch on the corresponding LEDs as OEN goes low.
Timing Diagrams
This section contains timing diagrams referenced in other sections of this data sheet.
Figure 9. Normal Mode Timing Diagram
Figure 10. Output De lay Timing Diagram
OEN
OUTNx
LD
SDO
SDI
CLK
tSU(L) tH(L)
tW(L)
tW(CLK)
tP1
tH(D)
50% 50% 50%
50% 50%
50%
tSU(D)
OEN Low = Output Enabled
tP2
OUTNx High = Output Off
OUTNx Low = Output On
50%
50% 50%
tW(OE)
14XtSTAG
tP3
OEN
OUTN0
OUTN1
OUTN15
50% 50%
50%50%
tOF tOR
tSTAG
90% 90%
10% 10%
14XtSTAG
tSTAG
tP3
50% 50%
50% 50%
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AS1110
Datasheet - D et a i l e d De s c r i p t i o n
Figure 11. Data Input Timing Diagram
Figure 12. Data Input Example Timing Diagram
SDI0
CLK
OEN
LD
SDO0
16 CLK Pulses
tSU(OE)
tW(L)
tSU(L)
tW(OE)
tH(D)
tP1
Data Bit
15 Data Bit
14 Data Bit
13 Data Bit
12 Data Bit
n Data Bit
2Data Bit
1Data Bit
0
Old Data
Bit 15 Old Data
Bit 14 Old Data
Bit 13 Old Data
Bit 12 Old Data
Bit n Old Data
Bit 2 Old Data
Bit 1 Old Data
Bit 0
Don’t Care
Don’t Care
tSU(D)
D6D7 D5 D4 D2 D1 D0
D3D14D1 D13 D12 D10 D9 D8
D11
SDI
OEN
LD
OUTN0
OUTN1
OUTN7
OUTN2
OUTN3
OUTN4
OUTN5
OUTN6
1234567
Time
CLK
OUTN8
OUTN9
OUTN15
OUTN10
OUTN11
OUTN12
OUTN13
OUTN14
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
Off
On
8910 11 12 13 14 15
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AS1110
Datasheet - D et a i l e d De s c r i p t i o n
Figure 13. Switching Global Error Mode Timing Diagram
Error-Detection Mode
Acquisition of the error status occurs at the rising edge of OEN. Error-detection mode is started on the rising edge of
LD when OEN is high. The CLK signal must be low when entering error detection mode. Error detection for open- and
shorted-LEDs can only be performed for LEDs that are switched on during test time. To switch between error-detection
modes clock pulses are needed (see Table 5).
Note: To test all LEDs, a test pattern that turns on all LEDs must be input to the AS1110.
Global Error Mode
Global error mode is entered when error-detection mode is star ted. Clock pulses during this period are used to select
between temperature, open-LED, and shorted-LED tests, as well as low-current diagnostic mode and shutdown mode
(see Tab le 5). In global error mode, an error flag (TFLAG, OFLAG, SFLAG) is delivered to pin SDO if any errors are
encountered.
Note: For a valid result SDI must be 1 for the first device.
Table 5. Global Error Mode Selections
Clock
Pulses Output Port Error-Detection Mode Global Error Flag/Shutdown Condition
0 Don't Care Over-Temperature
Detection TFLAG = SDO = 1: No over-temperature warning.
TFLAG = SDO = 0: Over-temperature warning.
1 Enabled Open-LED Detection OFLAG = SDO = 1: No open-LED error.
OFLAG = SDO = 0: Open-LED error.
2 Enabled Shorted-LED Detection SFLAG = SDO = 1: No shorted-LED error.
SFLAG = SDO = 0: Shorted-LED error.
3 Don't Care Low-Current Diagnostic
Mode
4 Don't Care Shutdown Mode SDI = 1: Wakeup
SDI = 0: Shutdown
tTESTING
tSU(ERROR)
OFLAG(IN) SFLAG(IN)TFLAG(IN)
TFLAG OFLAG SFLAG
tSW(ERROR)
SDI
OEN
LD
CLK
SDO Don’t
Care Don’t
Care
tGSW(ERROR)
tP(I/O)
tP4
tP(I/O) tP(I/O)
tSW(ERROR)
tGSW(ERROR)
tGSW(ERROR)
Don’t
Care
Acquisition of
Error Status
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AS1110
Datasheet - D et a i l e d De s c r i p t i o n
If there are multiple AS1110s in a chain, the error flag will be gated through all devices. To get a valid result at the end
of the chain, a logic 1 must be applied to the SDI input of the first device of the chain. If one device produces an error
this error will show up after n*tP(I/O) + tSW(ERROR) at pin SDO of the last device in the chain. This means it is not possi-
ble to identify which device in the chain produced the error. Therefore, if a global error occurs, the detailed error report
can be run to identify which AS1110, or LED produced the error.
Note: When no error has occurred, the detailed error report can be skipped, setting LD and sub se quently OEN low.
Error Detection Functions
Open-LED Detection
The AS1110 open-LED detection is based on the comparison between VDS and VTHL. The open LED status is aquired
at the rising edge of OEN and stored internally. While detecting open-L E Ds the output port must be turned on. Open
LED detection can be started with 1 clock pulse during error detection mode while the output port is turned on.
Note: LEDs which are turned off at test time cannot be tested and will be shown as a logic 1 in the detailed error
report.
Shorted-LED
The AS1110 shorted-LED detection is based on the comparison between VDS and VTHH. The shortened LED status is
aquired at the rising edge of OEN and stored internally. While detectin g shorted-LEDs the output port must be turned
on. Shorted-LED detection can be started with 2 clock pulses during error detection mode while the output port is
turned on.
For valid results, the voltage at OUTN0:OUTN15 must be lower then VTHH under low-current diagnostic mode operat-
ing conditions. This can be achieved by reducing the VLED voltage or by adding additional diodes, resistors or LED’s.
Note: LEDs which are turned off at test time cannot be tested and will be shown as a logic 1 in the detailed error
report.
Overtemperature
Thermal protection for the AS1110 is provided by continuously monitoring the device’s core temperature. The overtem-
perature status is aquired at the rising edge of OEN and stored internally.
Table 6. Open LED Detection Modes
Output Port State Effective Output
Point Conditions Detected Open-LED
Error Status Code Meaning
On VDS < VTHL 0 Open Circuit
On VDS > VTHL 1 Normal
Table 7. Shorted LED Detection Modes
Output Port State Effective Output
Point Conditions Detected Shorted-LED
Error St atus Code Meaning
On VDS > VTHH 0 Short Circuit
On VDS < VTHH 1 Normal
Table 8. Overtemperature Mo des
Output Port State Effective Output
Point Conditions Detected Overtemperature
Status Co de Meaning
Don’t Care Temperature > TOV1 0Overtemperature
Condition
Don’t Care Temperature < TOV1 1 Normal
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AS1110
Datasheet - D et a i l e d De s c r i p t i o n
Detailed Error Reports
The detailed error report can be read out after global error mode has been run. At the falling edge of LD, the detailed
error report of the selected test is latched into the shift register and can be clocked out with n*16 clock cycles (n is the
number of AS1110s in a chain) via pin SDO. At the same time new data can be written into the shift register, which is
loaded on the next rising edge of pin LD. This pattern is shown at the output drivers, at the falling edge of OEN.
Detailed Temperature Warning Report
The detailed temperature warning report can be read out immediately after global error mode has been run. SDI must
be 1 for the first device. Bit0 of the 16bit data word represents the temperature flag of the chip.
Figure 14. Detailed Temperature Warning Report Timing Diagram
Detailed Temperature Warning Report Example
Consider a case where four AS1110s are cascaded in one chain. The detaile d error report lists the te mpe ra tu r e s for
each device in the chain: IC1:[70°] IC2:[85°] IC3:[170°] IC4:[60°]
In this case, IC3 is overheated and will generate a global error, and therefore 4*16 clock cycles are needed to write out
the detailed temperature warning report, and optionally read in new data. The detailed temperature warning report
would look like this:
XXXXXXXXXXXXXXX1 XXXXXXXXXXXXXXX1 XXXXXXXXXXXXXXX0 XXXXXXXXXXXXXXX1
The 0 in the detailed temperature warning report indicates that IC3 is the device with the over-temperature condition.
Note: In an actual report there are no spaces in the output.
Global Flag Readout Detailed Error Report Readout
tH(L)
tP4
tP4
SDI
OEN
LD
CLK
SDO
New Data Input
TFLAG
DBit15
Undefined
Don’t
Care
Don’t
Care
Temperature Error Report Output
DBit14 DBit13 DBit12 DBitn DBit2 DBit1 DBit0
TBit0
t(SU)ERROR
tP1
For detailed timing information see Timing Diagr ams on page 9.
tGSW(ERROR)
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AS1110
Datasheet - D et a i l e d De s c r i p t i o n
Detailed Open-LED Error Report
The detailed open-LED error report can be read out immediately after global error mode has bee n run. SDI must be 1
for the first device.
Figure 15. Detailed Open-LED Error Report Timing Diagram
Detailed Open-LED Error Report Example
Consider a case where three AS1110s are cascaded in one chain. A 1 indicates a LED is on, a 0 indicates a LED is off,
and an X indicates an open LED. Th e open-LED test is only applied to LEDs that are turned on. This test is used with
a test pattern where all LEDs are on at test time.
IC1:[1111111111111111] IC2:[111XX11111111X11] IC3:[1111111111111111]
IC2 has three open LEDs switched on due to input. 3*16 clock cycles are needed to write the entire error code out. The
detailed error report would look like this:
Comparing this report with the input data indicates that IC2 is the device with two open LEDs at position 4 and 5 and
one open LED at positi on 14. For such a te st it is recommended to enter low-curren t di agnostic mode first (see Low-
Current Diagnostic Mode on page 15) to reduce screen flickering.
This test can be used also on-the-fly without using an all 1s test pattern (see Figure 19 on page 17).
Note: In an actual report there are no spaces in the output. LEDs turned off during test time cannot be tested and will
show a logic 1 in the detailed error report.
Input Data:1111111111111111 1111111111111111 1111111111111111
LED Status:1111111111111111 111XX11111111X11 1111111111111111
Failure Code:1111111111111111 1110011111111011 1111111111111111
Acquisition of
Error Status
Global Flag Readout Detailed Error Re port Readout
SDI
OEN
LD
CLK
SDO
tH(L)
Open Error Report Output
New Data Input
tP4
tP1
tP4
tSW(ERROR)
tSU(ERROR)
tTESTING
DBit0DBit1DBit2DBitnDBit12DBit13DBit14
OBit0OBit1OBit2OBitnOBit12OBit13OBit14
Don’t
Care
Don’t
Care
OBit15
TFlag OFlag
DBit15
For detailed timing information see Timing Diagrams on page 9.
tGSW(ERROR)
tGSW(ERROR)
tGSW(ERROR)
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AS1110
Datasheet - D et a i l e d De s c r i p t i o n
Detailed Shorted-LED Error Report
The detailed shorted-LED error report can be read out immediately after global error mode has been run (see Global
Error Mode on page 11). SDI must be 1 for the first device.
Figure 16. Detailed Shorted-LED Error Report Timing Diagram
Detailed Shorted-LED Error Report Example
Consider a case where three AS1110s are cascaded in one chain. A 1 indicates a LED is on, a 0 indicates a LED is off,
and an X indicates a shorted LED. This test is used on-the-fly.
IC1:[11111XX111111111] IC2:[1111111111111111] IC3:[X100011111111111]
IC1 has two shorted LEDs which are switched on, IC3 has one shorted LED switched off due to input. 3*16 clock
cycles are needed to write the entire error code out. The detailed error report would look like this:
Showing IC1 as the device with two shorted LEDs at position 6 and 7, and IC3 with one shorted LED at position 1. The
shorted LED at position 1 of IC3 cannot be detected, since LEDs turned off at test time are not tested and will show a
logic "1" at the detailed error report. To test all LEDs this test should be run with an all 1s test pattern. For a test with an
all on test pattern, low-current diagnostic mode should be entered first to reduce on-screen flickering.
Note: In an actual report there are no spaces in the output. LEDs turned off during test time cannot be tested and will
show a logic 1 in the detailed error report.
Low-Current Diagnostic Mode
To run the open- or shorted-LED test, a test pattern must be used that will turn on each LED to be tested. This test pat-
tern will cause a short flicker on the screen while the test is being performed. The low-current diagnostic mode can be
initiated prior to running a detailed error report to reduce this on-screen flickeri ng.
Note: Normally, displays using such a diagnostic mode require additional cables, resistors, and other components to
reduce the current. The AS1110 has this current-reduction capability built-in, thereby minimizing the number of
external components required.
Low-current diagnostic mode can be initiated via 3 clock pulses during error-detection mode. After the falling edge of
LD, a test pattern displaying all 1s can be written to the shift register which will be used for the next error-detection test.
Input Data: 1111111111111111 1111111111111111 0100011111111111
LED Status: 11111XX111111111 1111111111111111 X111111111111111
Failure Code: 1111100111111111 1111111111111111 1111111111111111
Global Flag Readout Detailed Error Report Readout
SDI
OEN
LD
CLK
SDO
tH(L)
tSU(ERROR)
tP1
tSW(ERROR)
tP4
TFLAG SFLAG
Acquisition of
Error Status
DBit14 DBit13 DBit12 DBitn DBit2 DBit1 DBit0 Don’t
Care
Don’t
Care
SBit14 SBit13 SBit12 SBitn SBit2 SBit1 SBit0SBit15
New Data Input
Shorted-LED Error Report Output
OFLAG
TFLAG
tP4
tTESTING
Global Flag Readout
DBit15
For detailed timin g information see Timing Diagrams on page 9.
tGSW(ERROR)
tGSW(ERROR)
tGSW(ERROR)
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AS1110
Datasheet - D et a i l e d De s c r i p t i o n
On the next falling edge of OEN, current is reduced to ILC. With the next rising edge of OEN the current will immedi-
ately increase to normal levels and the detailed error report can be read out entering error-detection mode.
Figure 17. Switching into Low-Current Diagnosti c Mode Timing Diagram
Shutdown Mode
The AS1110 features a shutdown mode which can be entered via 4 clock pulses during error-detection mode. To
enable the shutdown mode a 0 must be placed at SDI after the rising edge of the 3rd clock pulse.
To disable shutdown mode a 1 must be placed at SDI after the 3rd clock pulse. The shutdown/wakeup information will
be latched through if multiple AS1110 devices are in a chain. At the rising edge of the 4th clock pulse the shutdown bit
will be read out and the AS1110 will shutdown or wakeup.
Note: In shutdown mode the supply current drops down to <10µA.
Figure 18. Shutdown Mode Timing Diagram
For detailed timing information see Timing Diagrams on page 9.
OFLAGTFLAG SFLAG Don’t
Care
Re-entering Error
Detection Mode
(see Figure 15)
(see Figure 16)
tTESTING
SDI
OEN
LD
CLK
SDO
Load Internal all 1s
Test Pattern
(optional)
tSW(ERROR)
tP1
tSU(ERROR)
Normal Operation Current
tGSW(ERROR)
tGSW(ERROR)
Low-Current
Diagnosis Mode
tH(L)
SDI
OEN
LD
CLK
SDO
1 = Wakeup
0 = Shutdown
1 = Wakeup
0 = Shutdown
OFLAGTFLAG SFLAG
tP4
tSU(ERROR)
tSU(D)
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AS1110
Datasheet - App l i c a t i o n I n f o r m a t i o n
9 Application Information
Error Detection
The AS1110 features two types of error detection. The error detection can be used on-the-fly, for active LEDs, with out
any delay, or by entering into low-current diagnosis mode.
Error Detection On- T he-F l y
Error detection on-the-fly will output the status of active LEDs during operation. Without choosing an error mode this
will output the temperature flag at every input/output cycle. Triggering one clock pulse for open or two clock pulses for
short detection during error detection mode outputs the detailed open- or short-error report with the next input/output
cycle (see Figure 19). LEDs turned off at test time are not tested and will show a logic "1" at the detailed error report.
Figure 19. Normal Operation with Error Detection During Operation – 64 Cascaded AS1110s
Error Detection with Low-Current Diagnosis Mode
This unique feature of the AS1110 uses an internal all 1s test pattern for a flicker free diagnosis of all LEDs. This error
detection mode can be started at the end of each input cycle (see Figure 20).
Figure 20. Low-Current Diagnosis Mode with Internal All 1s Test Pattern – 64 Cascaded AS111 0s
Display
SDI
SDO
CLK
OEN
LD
Current
Data1 Data2 Data3
T/O or S Error Code
Data1
T/O or S Error Code
Data0 T/O or S Error Co de
Data2
1024x 1024x 1024x
Clock for Error
Mode 0x/1x/2x
Rising Edge of OEN
Acquisition of Error Status
Falling Edge of LD; Error Register is
copied into Shift Register
≤ 100mA
GEFGEF
GEF = Global Error Flag
Falling Edge of LD; Error Register is
copied into Shift Register
Clock for Error
Mode 0x/1x/2x
Rising Edge of OEN
Acquisition of Error Status
Data2 Data3 Data4
Clock for Error
Mode 1x/2x
3x Clocks Low-
Current Mode
GEF
1024x1024x
Data0
Rising Edge of OEN
Acquisition of Error Status
Falling Edge of LD; Error Register
is copied into Shift Register
GEF
O or S Error Code from
All 1s Test Pattern Temperature Error Code
Use Internal All 1s
Test Pattern
≤ 100mA ≤ 100mA
SDI
SDO
CLK
OEN
LD
≤ 0.8mA GEF = Global Error Flag
1024x
Data1 Data2
T/O or S Error Code
Data0 GEF
Display
Current
Low-Current Diagnosis Mode
Data2 Data3
Data1
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AS1110
Datasheet - App l i c a t i o n I n f o r m a t i o n
The last pattern written into the shift register will be saved before starting low-current diagnosis mode and can be dis-
played immediately after the test has been performed.
Low-current diagnostic mode is started with 3 clock pulses during error detection mode. Then OEN should be enabled
for ≥2µs for testing. With the rising edge of OEN the LED test is stopped, and while LD is high the desired error mode
can be selected with the corresponding clock pulses. After LD and OEN go low again the previously saved pattern can
be displayed at the outputs.
With the next data input the detailed error code will be clocked out at pin SDO.
Note: See Figure 21 for use of an external test pattern.
Figure 21. Low-Current Diagnosis Mode with External Test Pattern – 64 Cascaded AS1110s
Cascading Devices
To cascade multiple AS1110 devices, pin SDO must be connecte d to pin SDI of the next AS1110 (see Figure 22). At
each rising edge of CLK the LSB of the shift register will be written into the shift register SDI of the next AS1110 in the
chain.
Note: When n*AS1110 devices are in one chain, n*16 clock pulses are nee ded to latch-in the input data.
Figure 22. Cascading AS1110 Devices
Temperature Error Code
Data2
Data1
GEF GEF
T/O or S Err o r C o de
Data0
Rising Edge of OEN
Acquisition of Error Status
Display
SDI
SDO
CLK
OEN
LD
1024x
1024x
3x Clocks
Low-Current
Mode Clock for Error
Mode 1x/2x
Falling Edge of LD; Error Register
is copied into Shift Register
O or S Error Code
from Test Pattern
1024x
GEF = Global Error Flag
Low-Current Diagnosis Mode
≤ 100mA ≤ 100mA
Current
≤ 0.8mA
Data2 Data3
External all 1s Test Pattern
AS1110 #n-1
SDI SDO
CLK LD OEN
SDI
CLK
LD
OEN
AS1110 #1
SDI SDO
CLK LD OEN
AS11 10 #2
SDI SDO
CLK LD OEN
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AS1110
Datasheet - App l i c a t i o n I n f o r m a t i o n
Constant Current
In LED display applications, the AS1110 provides virtu ally no current variations from channel-to-channel and from
AS1110-to-AS1110. This is mostly due to 2 factors:
! While IOUT ≥ 10mA, the maximum current skew is less than ±3% between channels and less than ±6% between
AS1110 devices.
! In the saturation region, the characterist ic curve of the output stage is flat (see Figure 5 on page 7). Thus, the out-
put current can be kept constant regardless of the variations of LED forward voltages (VF).
Adjusting Output Current
The AS1110 scales up the reference current (IREF) set by external resistor (REXT) to sink a current (IOUT) at each out-
put port. As shown in Figure 3 on page 7 the output curr en t i n th e sa tu rat i on region is extremely fla t so th at it is po ssi -
ble to define it as target current (IOUT TARGET). IOUT TARGET can be calculated by:
VREXT = 1.253V (EQ 1)
IREF = VREXT/REXT (if the other end of REXT is connected to ground) (EQ 2)
IOUT TARGET = IREF*15 = (1.253V/REXT)*15 (EQ 3)
Where:
REXT is the resistance of the external resistor connected to pin REXT.
VREXT is the voltage on pin REXT.
The magnitude of current (as a function of REXT) is around 50.52mA at 372Ω and 25.26mA at 744Ω. Figure 3 on
page 7 shows the relationship curve between the IOUT TARGET of each channel and the corresponding external resistor
(REXT).
Package Power Dissipation
The maximum allowable package power dissipation (PD) is determined as:
PD(MAX) = (TJ-TAMB)/RTH(J-A) (EQ 4)
When 16 output channels are turn ed on simultaneously, the actual package power dissipation is:
PD(ACT) = (IDD*VDD) + (IOUT*Duty*VDS*16) (EQ 5)
Therefore, to keep PD(ACT) ≤ PD(MAX), the maximum allowed output current as a function of duty cycle is:
IOUT = {[(TJ-TAMB)/RTH(J-A)]-(IDD*VDD)}/VDS/Duty/16 (EQ 6)
Where:
TJ = 150ºC
Delayed Outputs
The AS1110 has graduated delay circuits between outputs. These delay circuits can be found between OUTNn and
constant current block.
The fixed delay time is 20 ns (typ) where OUTN0 has no delay, OUTN1 has 20ns delay, OUTN2 has 40ns delay ...
OUTN15 has 300ns delay. This delay prevents large inrush currents, which reduce power supply bypass capacitor
requirements when the outputs turn on (see Figure 11 on page 10)
Switching-Noise Reduction
LED drivers are frequently used in switch-mode applications which normally exhibit switching noise due to parasitic
inductance on the PCB.
Load Supply Voltage
Considering the package power dissipation limits (see EQ 4:6), the AS1110 should be operated within the range of
VDS = 0.4 to 1.0V.
For example, if VLED is higher than 5V, VDS may be so high that PD(ACT) > PD(MAX) where VDS = VLED - VF. In this case,
the lowest possible supply voltage or a voltage reducer (VDROP) should be used. The voltage reducer allows
VDS = (VLED -VF) - VDROP.
Note: Resistors or zener diodes can be used as a voltage reducer as shown in Figure 23.
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AS1110
Datasheet - Pa ck ag e D ra wi ng s a nd Mar ki ng s
10 Package Drawings and Markings
The AS1110 is available in a 28-pin QFN (5x5mm) package and a 24-pin SSOP package.
Figure 24. 28-pin QFN (5x5mm) Packagee
Notes:Unilateral coplanarity zone applies to the exposed heat sink slug as well as the terminals.
1. Dimensioning and tolerancing conform to ASME Y14.5M-1994.
2. All dimensions are in millimeters; angles in degrees.
3. N is the total number of terminals.
4. The terminal #1 identifier and terminal numbering convention shall conform to JEDEC 95 SPP-012. Details of termi-
nal #1 identifier are optional but must be located within the zone indicated. The te rminal #1 identifier may be either
a mold or marked feature.
5. Dimension b applies to metallized terminal and is measured between 0.15 and 0.30mm from terminal tip. If one end
of the terminal has the optional radius, the b dimen sion should not be measured in that radius area.
6. Dimensions ND and NE refer to the number of terminals on each D and E side, respectively.
-C-
A3
A1
SIDE VIEW
PLANE
A
ccc C
0.08 C
NX SEATING
D
D/2
INDEX AREA
E
aaa C
aaa C
TOP VIEW
2x
2x
4
(D/2 xE/2)
E/2
-B-
-A-
NXL
e
NXb
D2/2
D2
E2/2
2
1
E2
bbb C A B
ddd C
-B-
-A-
NN-1
BTM VIEW
65
(D/2 xE/2)
INDEX AREA
4
SEE
DETAIL B
SEE
DETAIL B
Datum A or B
ODD TERMINAL SIDE Terminal Tip
e
L1
5
Symbol Min Typ Max Notes
A 0.70 0.75 0.80 1, 2
A1 0.00 0.02 0.05 1, 2
A3 0.20 REF 1, 2
L 0.45 0.55 0.65 1, 2
L1 0.03 0.15 1, 2
aaa0.151, 2
bbb0.101, 2
ccc 0.10 1, 2
ddd0.051, 2
eee0.081, 2
ggg0.101, 2
Symbol Min Typ Max Notes
D BSC 5.00 1, 2
E BSC 5.00 1, 2
D2 3.00 3.15 3.25 1, 2
E2 3.00 3.15 3.25 1, 2
K0.20 1, 2
b 0.18 0.25 0.30 1, 2, 5
e0.50
N281, 2
ND 7 1, 2, 5
NE 7 1, 2, 5
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AS1110
Datasheet - O r d e r i n g I n f o r m a t i o n
11 Ordering Information
The device is available as the standard products shown in Table 9.
Note: All products are RoHS compliant and Pb-free.
Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect
For further information and requests, please contact us mailto:sales@austriamicrosystems.com
or find your local distributor at http://www.austriamicrosystems.com/distributor
Table 9. Ordering Information
Ordering Code Description Delivery Form Package
AS1110-BSSU Constant-Current, 16-Channel LED Driver with
Diagnostics Tubes 24-pin SSOP
AS1110-BSST Constant-Current, 16-Channel LED Driver with
Diagnostics Tape and Reel 24-pin SSOP
AS1110-BQFR Constant-Current, 16-Channel LED Driver with
Diagnostics Tray 28-pin QFN (5x5mm)
AS1110-BQFT Constant-Current, 16-Channel LED Driver with
Diagnostics Tape and Reel 28-pin QFN (5x5mm)
www.austriamicrosystems.com/LED-Driver-ICs/AS1110 Revision 1.05 24 - 24
AS1110
Datasheet
Copyrights
Copyright © 1997-2009, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe.
Trademarks Registered ®. All rights reserved. The material herein may not be reproduce d, adapted, merged,
translated, stored, or used without the prior written consent of the copyright owner.
All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing
in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding
the information set forth herein or regardi ng th e freedom of the described devices from patent infringement.
austriamicrosystems AG reserves the right to change specific ations and prices at any time and without notice.
Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for
current information. This product is intended for use in normal commercial applications. Applic ations requiring
extended temperature range, unusual environmental requirements, or high reliability applications, such as military,
medical life-support or life-sustaining equipment are specifically not recommended without additional processing by
austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show
deviations from the standard production flow, such as test flow or test location.
The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However,
austriamicrosystems AG shall not be liable to recipient or any third party for any damages, includ ing but not limited to
personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incide ntal or
consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the
technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of
austriamicrosystems AG rendering of technical or other services.
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Tobelbaderstrasse 30
A-8141 Unterpremstaetten, Austria
Tel: +43 (0) 3136 500 0
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