AS1110-BSST - Austriamicrosystems

A S111 0

Constant-Current, 16-Channel LED Driver with Diagnostics

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 1 - 24

1 General Description

The AS1110 is designed to drive up to 16 LEDs through a fast serial

interface and features 16 output constant current drivers and an on-

chip diagnostic read-back function.

The high clock-frequency (up to 50MHz), adjustable output current,

and flexible serial interface makes the device perfectly suited for

high-volume 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 global fault status information during load as well as

the detailed temperature/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 Assignments

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 current

Over-Temperature, Open-LED, Shorted-LED

Diagnostic functions

Low-current tes t 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) Packa ge

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 panels, 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

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 2 - 24

AS1110

Datasheet

4 Pin Assignments

Figure 2. Pin Assignments (Top Vie w)

4.1 Pin Descriptions

Table 1. Pin Descriptions

Pin Number Pin Name Description

SSOP QFN

124:27 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

AS1110 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 occurrence 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

GND

AS1110

24-pin SSOP

VDD

SDI

CLK

OUTN0

REXT

SDO

OEN

OUTN12

OUTN3

OUTN2

OUTN1

OUTN15

OUTN14

OUTN13

OUTN4

OUTN8

OUTN7

OUTN6

OUTN5

OUTN11

OUTN10

OUTN9

SDO

OUTN7

OUTN5

OUTN13

CLK 1

OUTN0 3

OUTN4 7

AS1110

28-pin QFN 5x5

OUTN2 5

OUTN8

OUTN10

OUTN11

OUTN15

OEN

OUTN14

OUTN12

LD 2

OUTN1 4

OUTN3 6

OUTN9

N/C

OUTN6

GND

SDI

2628

GND

REXT

VDD

GND

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 3 - 24

AS1110

Datashee t - A b s o l u t e M a x i mu m R a t i n g s

5 Absolute Maximum Ratings

Stresses beyond those listed 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 Electrical Characteristics on page 4 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 temperature (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).

Moisture Sensitivity

Level SOIC 3 Represents a maximum floor life of 168h

QFN 1 Represents an infinite floor lifetime

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 4 - 24

AS1110

Datasheet - Electrical Characteristics

6 Electrical Characteristics

VDD = +3.0V to +5.5V, 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 V o ltage OUTN0:15 0 15.0 V

IOUT

Output Current

OUTN0:15, VDD = 5V (see Figure 7) 0.5 100

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 ºC

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 5 - 24

AS1110

Datasheet - Electrical Characteristics

6.1 Switching Characteristics

VDD = 3.0 to 5.5V, VDS = 0.8V, VIH = VDD, VIL = GND, REXT = 372Ω, VLOAD = 4.0V, RLOAD = 64Ω, CLOAD = 10pF; guaranteed by design.

IDD(OFF)0

Supply Current

OFF

REXT = Open‚ OUTN0:15 = Off 2.7 6

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

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) Propagation Delay Global Error Flag 5 ns

tSW(ERROR) Switching Time Global Error Flag 10 ns

fCLK Maximum Clock Frequenc y

(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

Table 3. Electrical Characteristics (Continued)

Symbol Parameter Condition Min Typ Max Unit

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 6 - 24

AS1110

Datasheet - Electrical Characteristics

* 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.

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 4. Switching Characteristics for VDD = 5V

Symbol Parameter Conditions Min Typ Max Unit

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 7 - 24

AS1110

Datasheet - Typical Operating Characteristics

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

0.5

1.5

33.544.555.5

VDD (V)

Relat iv e Out put Cur r ent Er r or (%)

REXT = 744Ω;

VDS = 0.5V

REXT = 372Ω;

VDS = 0.6V

REXT = 186Ω;

VDS = 0.8V

100

100 1000 10000

RE XT ( )

IOUT (mA) .

100

120

0 0.2 0.4 0.6 0.8 1 1.2 1.4

VDS (V)

IOUT (mA) .

100

120

03691215

VDS (V)

IOUT (mA) .

REXT = 251Ω

REXT = 372Ω

REXT = 186Ω

REXT = 744Ω

REXT = 251Ω

REXT = 372Ω

REXT = 186Ω

REXT = 744Ω

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

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 8 - 24

AS1110

Datasheet - Detailed Description

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 conditions for LED display systems, especially LED traffic

sign application s.

The AS1110 contains an 16-bit shift register and an 16-bit data register, which convert serial input data into parallel output format. At AS1110

output stages, sixteen regulated current sinks are designed to provide uniform and constant current 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 requirements of high-volume data transmission.

Using a multiplexed input/output technique, the AS1 110 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 detection can be used on-the-run or in low-current diagnostic mode (s ee page 15).

Figure 8. AS1110 - Block Dia gram

8.1 Serial Interface

Data accesses are made serially via pins SDI and SDO. At each CLK rising edge, the 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 temperature-, open-, and short-error register with each falling edge of LD.

AS1110

REXT

OEN

CLK

SDI

Current

Generators

Detailed

Error

Detection

16-Bit Data

16-Bit Shift

Temperature

Detection 16-Bit Open

Detection & Error

16-Bit Short

Detection & Error

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

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 9 - 24

AS1110

Datasheet - Detailed Description

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.

8.2 Timing Diagrams

This section contains timing diagrams referenced in other sections of this data sheet.

Figure 9. Normal Mode Timing Diagram

Figure 10. Output Delay Timing Diagram

OEN

OUTNx

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%

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 10 - 24

AS1110

Datasheet - Detailed Description

Figure 11. Data Input Timing Diagram

Figure 12. Data Input Example Timing Diagram

SDI0

CLK

OEN

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

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

tSU(D)

D6D7 D5 D4 D2 D1 D0

D3D14D1 D13 D12 D10 D9 D8

D11

SDI

OEN

OUTN0

OUTN1

OUTN7

OUTN2

OUTN3

OUTN4

OUTN5

OUTN6

1234567

Time =

CLK

OUTN8

OUTN9

OUTN15

OUTN10

OUTN11

OUTN12

OUTN13

OUTN14

Off

8910 11 12 13 14 15

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 11 - 24

AS1110

Datasheet - Detailed Description

Figure 13. Switching Global Error Mode Timing Diagram

8.3 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.

8.4 Global Error Mode

Global error mode is entered when error-detection mode is started. 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 Table 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.

If there are multiple AS11 10s 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 possible 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 subsequently OEN low.

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 Enab led Shorted-LED De tection 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

CLK

SDO Don’t

Care Don’t

Care

tGSW(ERROR)

tP(I/O)

tP4

tP(I/O) tP(I/O)

tSW(ERROR)

tGSW(ERROR)

Don’t

Care

Acquisition of Error

Status

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 12 - 24

AS1110

Datasheet - Detailed Description

8.5 Error Detection Functions

8.5.1 Open-LED Detection

The AS1 110 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-LEDs 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.

8.5.2 Shorted-LED

The AS1 110 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 detecting 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 operating 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.

8.5.3 Overtemperature

Thermal protection for the AS1110 is provided by continuously monitoring the device’s core temperature. The overtemperature 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 Status Code Meaning

On VDS > VTHH 0 Short Circuit

On VDS < VTHH 1 Normal

Table 8. Overtemperature Modes

Output Port State Effective Output

Point Conditions Detected Overtemperature

Status Code Meaning

Don’t Care Temperature > TOV1 0 Overtemperature Condition

Don’t Care Temperature < TOV1 1Normal

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 13 - 24

AS1110

Datasheet - Detailed Description

8.6 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 cyc les (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.

8.6.1 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 detailed error report lists the temperatures 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

SDI

OEN

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 Diagrams on page 9.

tGSW(ERROR)

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 14 - 24

AS1110

Datasheet - Detailed Description

8.6.2 Detailed Open-LED Error Report

The detailed open-LED error report can be read out immediately after global error mode has been 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. The 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 position

14. For such a test it is recommended to enter low-current diagnostic 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 Report Readout

SDI

OEN

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)

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 15 - 24

AS1110

Datasheet - Detailed Description

8.6.3 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. Deta iled 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:[111111111111111 1] IC3:[X1000111111 11111]

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.

8.6.4 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 pattern 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 flickering.

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.

On the next falling edge of OEN, current is reduced to ILC. With the next rising edge of OEN the current will immediately increase to normal

levels and the detailed error report can be read out entering error-detection mode.

Input Data: 1111111111111111 1111111111111111 0100011111111111

LED Status: 11111XX111111111 1111111111111111 X111111111111111

Failure Code: 1111100111111111 1111111111111111 1111111111111111

Global Flag Readout Detailed Error Report Readout

SDI

OEN

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 timing information see Timing Diagrams on page 9.

tGSW(ERROR)

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 16 - 24

AS1110

Datasheet - Detailed Description

Figure 17. Switching into Low-Current Diagnostic Mode Timing Diagram

8.7 Shutdown Mode

The AS11 10 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

CLK

SDO

Load Internal all 1s T est

Pattern

(optional)

tSW(ERROR)

tP1

tSU(ERROR)

Normal Operation Current

tGSW(ERROR)

Low-Current

Diagnosis Mode

tH(L)

SDI

OEN

CLK

SDO

1 = Wakeup

0 = Shutdown

1 = Wakeup

0 = Shutdown

OFLAGTFLAG SFLAG

tP4

tSU(ERROR)

tSU(D)

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 17 - 24

AS1110

Datasheet - Application Information

9 Application Information

9.1 Error Detection

The AS1110 features two types of error detection. The error detection can be used on-the-fly, for active LEDs, without any delay, or by entering

into low-current diagnosis mode.

9.1.1 Error Detection On-The-Fly

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

9.1.2 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 AS1110s

Display

SDI

SDO

CLK

OEN

Current

Data1 Data2 Data3

T/O or S Error Code

Data1

T/O or S Error Code Data0

Data0 T/O or S Error Code

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 fo r Error M ode

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 cop-

ied into Shift Register

GEF

O or S Error Code from

All 1s Test Pattern Temperature Error Code

Use Internal All 1s T est

Pattern

≤ 100mA ≤ 100mA

SDI

SDO

CLK

OEN

≤ 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

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 18 - 24

AS1110

Datasheet - Application Information

The last pattern written into the shift register will be saved before starting low-current diagnosis mode and can be displayed 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

9.2 Cascading Devices

To cascade multiple AS1110 devices, pin SDO must be connected 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 AS1 110 in the chain.

Note: When n*AS1110 devices are in one chain, n*16 clock pulses are needed to latch-in the input data.

Figure 22. Cascading AS1110 Devices

Temperature Error Code

Data2

Data1

GEF GEF

T/O or S Error Code

Data0

Rising Edge of OEN

Acquisition of Error Status

Display

SDI

SDO

CLK

OEN

1024x

3x Clocks

Low-Current

Mode Clock for Error

Mode 1x/2x

Falling Edge of LD; Error Register is cop-

ied 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

OEN

AS1110 #1

SDI SDO

CLK LD OEN

AS1110 #2

SDI SDO

CLK LD OEN

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 19 - 24

AS1110

Datasheet - Application Information

9.3 Constant Current

In LED display applications, the AS1110 provides virtually 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 characteristic curve of the output stage is flat (see Figure 5 on page 7). Thus, the output current can be kept

constant regardless of the variations of LED forward voltages (VF).

9.4 Adjusting Output Current

The AS1110 scales up the reference current (IREF) set by external resistor (REXT) to sink a current (IOUT) at each output port. As shown in

Figure 3 on page 7 the output current in the saturation region is extremely flat so that it is possible 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).

9.5 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 turned 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

9.6 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)

9.7 Switching-Noise Reduction

LED drivers are frequently used in switch-mode applications which normally exhibit switching noise due to parasitic inductance on the PCB.

9.8 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 hi gh t hat P D(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.

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 20 - 24

AS1110

Datasheet - Application Information

Figure 23. Voltage Reducer using Resistor (Left) and Zener Diode (Right)

AS1110

VDS

Voltage Supply

}

VLED VDROP

AS1110

VDS

VLED

VDROP

V o ltage Supply

{

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 21 - 24

AS1110

Datasheet - Package Drawings and Markings

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) Package

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 terminal #1 identifier are

optional but must be located within the zone indicated. The terminal #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 dimension 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-

SIDE VIEW

PLANE

ccc C

0.08 C

SEATING

D/2

INDEX AREA

aaa C

TOP VIEW

(D/2 xE/2)

E/2

-B-

-A-

NXb

D2/2

bbb

ddd

-B-

N-1

BTM VIEW

(D/2 xE/2)

INDEX AREA

SEE

DETAIL B

SEE

DETAIL B

Datum A or B

ODD TERMINAL SIDE Terminal Tip

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

aaa 0.15 1, 2

bbb 0.10 1, 2

ccc 0.10 1, 2

ddd 0.05 1, 2

eee 0.08 1, 2

ggg 0.10 1, 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

K 0.20 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

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 22 - 24

AS1110

Datasheet - Package Drawings and Markings

Figure 25. 24-p in SSOP Package

Symbol Min Max

A1.351.75

A1 0.10 0.25

A2 1.37 1.57

b0.200.30

C0.190.25

D8.558.74

E5.796.20

E1 3.81 3.99

e 0.635 BSC

h0.220.49

L0.401.27

θ0º 8º

www.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 23 - 24

AS1110

Datasheet - Ordering Information

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 www.ams.com/ICdirect

Technical Support is available at www.ams.com/Technical-Support

For further information and requests, email us at sales@ams.com

(or) find your local distributor at www.ams.com/distributor

Table 9. Ordering Information

Ordering Code Description Delivery Form Package

AS1110-BSSU Constant-Current, 16-Channel LED Driver with Diagnostics Tu bes 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.ams.com/LED-Driver-ICs/AS1110 Revision 1.6 24 - 24

AS1110

Datasheet

Copyrights

reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the

All products and companies mentioned are trademarks or registered trademarks of their respective companies.

Disclaimer

Devices sold by ams AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. ams AG makes no

warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described

devices from patent infringement. ams AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior

to designing this product into a system, it is necessary to check with ams AG for current information. This product is intended for use in normal

commercial applications. Applications 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 ams 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 ams AG is believed to be correct and accurate. However, ams AG shall not be liable to recipient or any third

party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or

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