ADS-919
14-Bit, 2MHz, Low-Power
Sampling A/D Converters
Figure 1. ADS-919 Functional Block Diagram
FEATURES
14-bit resolution
2MHz sampling rate
No missing codes
Functionally complete
Small 24-pin DDIP or SMT package
Low power, 1.8 Watts
Operates from ±15V or ±12V supplies
Edge-triggered; No pipeline delays
Unipolar 0 to +10V input range
GENERAL DESCRIPTION
The ADS-919 is a high-performance, 14-bit, 2MHz sampling
A/D converter. This device accurately samples full-scale input
signals up to Nyquist frequencies with no missing codes. The
ADS-919 features outstanding dynamic performance including
a THD of –74dB.
Housed in a small 24-pin DDIP or SMT (gull-wing) package,
the functionally complete ADS-919 contains a fast-settling
sample-hold amplifier, a subranging (two-pass) A/D converter,
a precise voltage reference, timing/control logic, and error-
correction circuitry. Digital input and output levels are TTL.
Requiring ±15V (or ±12V) and +5V supplies, the ADS-919
typically dissipates 1.8W (1.5W for ±12V). The unit is offered
with a unipolar input (0 to +10V). Models are available for use
in either commercial (0 to +70°C) or military (–55 to +125°C)
operating temperature ranges. Applications include radar,
sonar, spectrum analysis, and graphic/medical imaging.
INPUT/OUTPUT CONNECTIONS
PIN FUNCTION PIN FUNCTION
1 BIT 14 (LSB) 24 –12V/–15V SUPPLY
2 BIT 13 23 ANALOG GROUND
3 BIT 12 22 +12V/+15V SUPPLY
4 BIT 11 21 +10V REFERENCE OUT
5 BIT 10 20 ANALOG INPUT
6 BIT 9 19 ANALOG GROUND
7 BIT 8 18 BIT 1 (MSB)
8 BIT 7 17 BIT 2
9 BIT 6 16 START CONVERT
10 BIT 5 15 EOC
11 BIT 4 14 DIGITAL GROUND
12 BIT 3 13 +5V SUPPLY
DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.) Tel: (508) 339-3000 Fax: (508) 339-6356 For immediate assistance: (800) 233-2765
REF
REGISTER
REGISTER
18 BIT 1 (MSB)
17 BIT 2
12 BIT 3
11 BIT 4
10 BIT 5
9 BIT 6
8 BIT 7
7 BIT 8
6 BIT 9
5 BIT 10
4 BIT 11
3 BIT 12
2 BIT 13
1 BIT 14 (LSB)
TIMING AND
CONTROL LOGIC
+10V REF. OUT 21
START CONVERT 16
EOC 15
DIGITAL CORRECTION LOGIC
DAC
FLASH
ADC
BUFFER
+
S/H
ANALOG INPUT 20
13
+5V SUPPLY
22
+12V/+15V SUPPLY
19, 23
ANALOG GROUND
14
DIGITAL GROUND
24
–12V/–15V SUPPLY
S
2
S
1
®®
A SUBSIDIARY OF C&D TECHNOLOGIES
®®
ADS-919
2
ABSOLUTE MAXIMUM RATINGS
PARAMETERS LIMITS UNITS
+12V/+15V Supply (Pin 22) 0 to +16 Volts
–12V/–15V Supply (Pin 24) 0 to –16 Volts
+5V Supply (Pin 13) 0 to +6 Volts
Digital Input (Pin 16) –0.3 to +VDD +0.3 Volts
Analog Input (Pin 20) –4 to +17 Volts
Lead Temperature (10 seconds) +300 °C
PHYSICAL/ENVIRONMENTAL
PARAMETERS MIN. TYP. MAX. UNITS
Operating Temp. Range, Case
ADS-919MC, GC 0 +70 °C
ADS-919MM, GM –55 +125 °C
Thermal Impedance
θj
c 6 °C/Watt
θ
ca 24 °C/Watt
Storage Temperature –65 +150 °C
Package Type 24-pin, metal-sealed, ceramic DDIP or SMT
Weight 0.42 ounces (12 grams)
+25°C 0 to +70°C 55 to +125°C
ANALOG INPUT MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS
Input Voltage Range
0 to +10 0 to +10 0 to +10 Volts
Input Resistance —1 1 1
k
Input Capacitance 7 15 7 15 7 15 pF
DIGITAL INPUT
Logic Levels
Logic "1" +2.0 +2.0 +2.0 Volts
Logic "0" +0.8 +0.8 +0.8 Volts
Logic Loading "1" +20 +20 +20 µA
Logic Loading "0" –20 –20 –20 µA
Start Convert Positive Pulse Width
20 200 20 200 20 200 ns
STATIC PERFORMANCE
Resolution 14 14— 14—Bits
Integral Nonlinearity (fin = 10kHz) ±0.5 ±0.75 ±1 LSB
Differential Nonlinearity (fin = 10kHz) ±0.5 ±0.95 ±0.5 ±0.95 ±0.5 ±0.99 LSB
Full Scale Absolute Accuracy ±0.1 ±0.3 ±0.2 ±0.4 ±0.4 ±0.8 %FSR
Unipolar Offset Error (Tech Note 2) ±0.1 ±0.25 ±0.2 ±0.4 ±0.4 ±1.25 %FSR
Gain Error (Tech Note 2) ±0.1 ±0.3 ±0.3 ±0.5 ±0.5 ±1 %
No Missing Codes (fin = 10kHz) 14 14 14 Bits
DYNAMIC PERFORMANCE
Peak Harmonics (–0.5dB)
dc to 500kHz 76 –72 76 –70 –74 –69 dB
500kHz to 1MHz 76 –70 76 70 –74 69 dB
Total Harmonic Distortion (–0.5dB)
dc to 500kHz 74 –70 74 –70 –73 –69 dB
500kHz to 1MHz –74 –70 74 70 –73 68 dB
Signal-to-Noise Ratio
(w/o distortion, –0.5dB)
dc to 500kHz 74 77 74 77 71 76 dB
500kHz to 1MHz 74 77 74 77 71 75 dB
Signal-to-Noise Ratio
(& distortion, –0.5dB)
dc to 500kHz 70 74 70 74 68 73 dB
500kHz to 1MHz 70 74 70 74 68 72 dB
Two-Tone Intermodulation
Distortion (fin = 200kHz,
500kHz, fs = 2MHz, –0.5dB) 80 80 79 dB
Noise 300 350 450 µVrms
Input Bandwidth (–3dB)
Small Signal (–20dB input) 9 9 9 MHz
Large Signal (–0.5dB input) 8 8 8 MHz
Feedthrough Rejection (fin = 1MHz) 82 82 82 dB
Slew Rate ±200 ±200 ±200 V/µs
Aperture Delay Time ±20 ±20 ±20 ns
Aperture Uncertainty 5 5 5 ps rms
S/H Acquisition Time
(to ±0.003%FSR, 10V step) 150 190 230 150 190 230 150 190 230 ns
Overvoltage Recovery Time
400 500 400 500 400 500 ns
A/D Conversion Rate 2 2 2 MHz
FUNCTIONAL SPECIFICATIONS
(TA = +25°C, ±VCC = ±15V (or ±12V), +VDD = +5V, 2MHz sampling rate, and a minimum 1 minute warmup
unless otherwise specified.)
®®
ADS-919
3
This is the time required before the A/D output data is valid after the analog input
is back within the specified range.
+25°C 0 to +70°C –55 to +125°C
ANALOG OUTPUT MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS
Internal Reference
Voltage +9.95 +10 +10.05 +9.95 +10 +10.05 +9.95 +10 +10.05 Volts
Drift ±5 ±5 ±5 ppm/°C
External Current 1.5 1.5 1.5 mA
DIGIT AL OUTPUTS
Logic Levels
Logic "1" +2.4 +2.4 +2.4 Volts
Logic "0" +0.4 +0.4 +0.4 Volts
Logic Loading "1" 4 –4 –4 mA
Logic Loading "0" +4 +4 +4 mA
Delay, Falling Edge of EOC
to Output Data Valid 35 35 35 ns
Output Coding Straight Binary
POWER REQUIREMENTS, ±15V
Power Supply Ranges
+15V Supply +14.5 +15 +15.5 +14.5 +15 +15.5 +14.5 +15 +15.5 Volts
–15V Supply –14.5 –15 –15.5 –14.5 –15 –15.5 –14.5 –15 –15.5 Volts
+5V Supply +4.75 +5 +5.25 +4.75 +5 +5.25 +4.75 +5 +5.25 Volts
Power Supply Currents
+15V Supply +45 +60 +45 +60 +45 +60 mA
–15V Supply –45 60 –45 –60 –45 –60 mA
+5V Supply +85 +95 +85 +95 +85 +95 mA
Power Dissipation 1.8 2.2 1.8 2.2 1.8 2.2 Watts
Power Supply Rejection ±0.02 ±0.02 ±0.02 %FSR/%V
POWER REQUIREMENTS, ±12V
Power Supply Ranges
+12V Supply +11.5 +12 +12.5 +11.5 +12 +12.5 +11.5 +12 +12.5 Volts
–12V Supply –11.5 –12 –12.5 –11.5 –12 –12.5 –11.5 –12 –12.5 Volts
+5V Supply +4.75 +5 +5.25 +4.75 +5 +5.25 +4.75 +5 +5.25 Volts
Power Supply Currents
+12V Supply +45 +65 +45 +65 +45 +65 mA
–12V Supply –45 –60 –45 –60 –45 –60 mA
+5V Supply +85 +95 +85 +95 +85 +95 mA
Power Dissipation 1.5 1.7 1.5 1.7 1.5 1.7 Watts
Power Supply Rejection ±0.02 ±0.02 ±0.02 %FSR/%V
Footnotes:
All power supplies must be on before applying a start convert pulse. All supplies
and the clock (START CONVERT) must be present during warmup periods. The
device must be continuously converting during this time. There is a slight
degradation in performance when using ±12V supplies.
See Ordering Information for availability of ±5V input range. Contact DATEL for
availability of other input voltage ranges.
A 2MHz clock with a 200ns wide start convert pulse is used for all production
testing. See Timing Diagram for more details.
6.02
(SNR + Distortion) – 1.76 + 20 log Full Scale Amplitude
Actual Input Amplitude
Effective bits is equal to:
TECHNICAL NOTES
1. Obtaining fully specified performance from the ADS-919
requires careful attention to pc-card layout and power
supply decoupling. The device's analog and digital ground
systems are connected to each other internally. For optimal
performance, tie all ground pins (14, 19 and 23) directly to a
large analog ground plane beneath the package.
Bypass all power supplies and the REFERENCE OUTPUT
(pin 21) to ground with 4.7µF tantalum capacitors in parallel
with 0.1µF ceramic capacitors. Locate the bypass capaci-
tors as close to the unit as possible. If the user-installed
offset and gain adjusting circuit shown in Figure 2 is used,
also locate it as close to the ADS-919 as possible.
2. The ADS-919 achieves its specified accuracies without the
need for external calibration. If required, the device's small
initial offset and gain errors can be reduced to zero using
the input circuit of Figure 2. When using this circuit, or any
similar offset and gain-calibration hardware, make adjust-
ments following warmup. To avoid interaction, always
adjust offset before gain.
3. When operating the ADS-919 from ±12V supplies, do not
drive external circuitry with the REFERENCE OUTPUT. The
reference's accuracy and drift specifications may not be
met, and loading the circuit may cause accuracy errors
within the converter.
4. Applying a start convert pulse while a conversion is in
progress (EOC = logic "1") initiates a new and inaccurate
conversion cycle. Data for the interrupted and subsequent
conversions will be invalid.
®®
ADS-919
4
Zero/Offset Adjust Procedure
1. Apply a train of pulses to the START CONVERT input
(pin 16) so the converter is continuously converting. If
using LED's on the outputs, a 200kHz conversion rate will
reduce flicker.
2. Apply +305µV to the ANALOG INPUT (pin 20).
3. Adjust the offset potentiometer until the output bits are
all 0's and the LSB flickers between 0 and 1.
Gain Adjust Procedure
1. Apply +9.999085V to the ANALOG INPUT (pin 20).
2. Adjust the gain potentiometer until the output bits are all 1's
and the LSB flickers between 1 and 0.
INPUT VOLTAGE ZERO ADJUST GAIN ADJUST
RANGE +½ LSB +FS –1½ LSB
0 to +10V +305µV +9.999085V
Table 1. Zero and Gain Adjust
INPUT VOLTAGE UNIPOLAR DIGITAL OUTPUT
(0 TO +10V) SCALE MSB LSB
+9.999390 +FS – 1LSB 11 1111 1111 1111
+7.500000 +3/4FS 11 0000 0000 0000
+5.000000 +1/2FS 10 0000 0000 0000
+2.500000 +1/4FS 01 0000 0000 0000
+0.000610 +1LSB 00 0000 0000 0001
0.000000 0 00 0000 0000 0000
Table 2. Output Coding
Figure 3. Typical ADS-919 Connection Diagram
CALIBRATION PROCEDURE
(Refer to Figures 2 and 3)
Any offset and/or gain calibration procedures should not be
implemented until devices are fully warmed up. To avoid
interaction, offset must be adjusted before gain. The ranges of
adjustment for the circuit of Figure 2 are guaranteed to
compensate for the ADS-919's initial accuracy errors and may
not be able to compensate for additional system errors.
All fixed resistors in Figure 2 should be metal-film types, and
multiturn potentiometers should have TCR’s of 100ppm/°C or
less to minimize drift with temperature.
A/D converters are calibrated by positioning their digital
outputs exactly on the transition point between two adjacent
digital output codes. This can be accomplished by connecting
LED's to the digital outputs and adjusting until certain LED's
"flicker" equally between on and off. Other approaches
employ digital comparators or microcontrollers to detect when
the outputs change from one code to the next.
For the ADS-919, offset adjusting is normally accomplished at
the point where the output bits are 0's and the LSB just
changes from a 0 to a 1. This digital output transition ideally
occurs when the applied analog input is +½ LSB (+305µV).
Gain adjusting is accomplished when all bits are 1's and the
LSB just changes from a 1 to a 0. This transition ideally
occurs when the analog input is at +full scale minus 1½ LSB's
(+9.999085V).
Figure 2. ADS-919 Calibration Circuit
Coding is straight binary; 1LSB = 610µV.

ADS-919































 !
 !
"
 !
 !
 !
 !
"
"
#$#
"$" "
 ! "
 !
 "!
%
%
&'"

%
To Pin 20
of ADS-919
–15V
SIGNAL
INPUT
GAIN
ADJUST
1.98k
50
+15V
2k
200k
20k
–15V
+15V
ZERO/
O
FFSET
ADJUST
®®
ADS-919
5
THERMAL REQUIREMENTS
All DATEL sampling A/D converters are fully characterized and
specified over operating temperature (case) ranges of
0 to +70°C and –55 to +125°C. All room-temperature
(TA = +25°C) production testing is performed without the use of
heat sinks or forced-air cooling. Thermal impedance figures
for each device are listed in their respective specification
tables.
These devices do not normally require heat sinks, however,
standard precautionary design and layout procedures should
be used to ensure devices do not overheat. The ground and
power planes beneath the package, as well as all pcb signal
runs to and from the device, should be as heavy as possible to
help conduct heat away from the package.
Electrically-insulating, thermally-conductive "pads" may be
installed underneath the package. Devices should be
soldered to boards rather than "socketed", and of course,
minimal air flow over the surface can greatly help reduce the
package temperature.
In more severe ambient conditions, the package/junction
temperature of a given device can be reduced dramatically
(typically 35%) by using one of DATEL's HS Series heat sinks.
See Ordering Information for the assigned part number. See
page 1-183 of the DATEL Data Acquisition Components
Catalog for more information on the HS Series. Request
DATEL Application Note AN-8, "Heat Sinks for DIP Data
Converters", or contact DATEL directly, for additional
information.
Figure 4. ADS-919 Timing Diagram
Notes: 1. fs = 2MHz.
2. The ADS-919 is an edge-triggered device. All internal operations
are triggered by the rising edge of the start convert pulse, which
may be as narrow as 20nsec. All production testing is performed
at a 2MHz sampling rate with 200nsec wide start pulses. For
lower sampling rates, wider start pulses may be used, however, a
minimum pulse width low of 20nsec must be maintained.



%
"
%(&(#()*+
,-
&./
$0
123*-*&*',*45
,-&./
%(&(()*+

,-&./ ',657-*',*45
,-4(8
,-9,-
,-4(8
,-4*, ,6()*+
%(&(
,-9,-
0')+
,-
9,-
,-&./
®®
ADS-919
6
Figure 5. ADS-919 Evaluation Board Schematic
32
30
28
26
24
22
20
33
6
8
10
12
14
16
18
31
27
29
23
25
19
21
3
5
7
9
11
13
15
P2
17
1
2
4
34
5%200K
R3
0.1%
1.98K
R4
+
U6
2
3
4
6
7
OP-77
1Y1
1Y2
1Y3
1Y4
2Y1
2Y2
2Y3
2Y4
1G
2G
2A4
2A3
2A2
2A1
1A4
1A3
1A2
1A1
U3
2
4
6
8
11
13
15
17
19
10
20
18
16
14
12
9
7
5
3
1
74LS240
.1%2K
R5
0.1%
10K
R8
P3
P4
74LS86
U4
9
10 8
74LS86
U4
12
13
11
0.1MF
C7
0.1MF
C5
0.1MF
C3
0.1MF
C17
0.1MF
C16
0.1MF
C1
0.1MF
C15
15pF
C2
0.1MF
C10
0.1MF
C12
0.1MF
C13
2.2MF
C6
+
2.2MF
C4
+
2.2MF
C9
+
2.2MF
C8
+
2.2MF
C11
+
2.2MF
C14
+
+5V
+5V
+5V
+5V
+15V
+15V
+15V
+15V
-15V
-15V
-15V
-15V
+5V
P1
1
2
56
4 3
8 7
10 9
12 11
14 13
16 15
18 17
20 19
22 21
24 23
26
25
20K
R2
50
R1
74LS86
U4
4
5
6
74LS86
U4
1
2
3
7
14
B1
B2
B14
B13
B12
B11
B10
B9
B8
B7
B6
B5
B4
B3
EOC
+5V
DGND
ST. CONV
AGND
INPUT
+10VREF
+15V
AGND
-15V
U1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
SG1
+
U5
2
3
4
6
7
AD845
0.1%
10K
R7
0.1%
2K
R6
-15V
2.2
MF
C22
+
0.1MF
C23
+15V
2.2MF
C19
+
0.1MF
C20
Y1
1
78
14
XTAL
J3
J5
J4
J2
0.1MF
C21
J1
+5V
0.1MF
C18
SG2
SG3
2.2MF
C24
+
1Y1
1Y2
1Y3
1Y4
2Y1
2Y2
2Y3
2Y4
1G
2G
2A4
2A3
2A2
2A1
1A4
1A3
1A2
1A1
U2
2
4
6
8
11
13
15
17
19
10
20
18
16
14
12
9
7
5
3
1
74LS240
B13
B11
B12
B10
B9
B6
B5
B4
B3
B14
B1
B2
B8
B7
2. FOR ADS-916 Y1 IS 500 KHZ.
1. SG1 SHOULD BE OPEN. SG2 &
FOR ADS-919/929 Y1 IS 2 MHZ.
FOR ADS-917 Y1 IS 1 MHZ.
SG3 SHOULD BE CLOSED.
NOTES:
SEE NOTE 1
ST.CONV.
ENABLE
MSB
LSB
EOC
COG
ADJ
GAIN
ADJ
OFFSET
CONVERT
START
INPUT
ANALOG
ADS-916/917/919/929
®®
ADS-919
7
Figure 6. ADS-919 FFT Analysis
Figure 7. ADS-919 Histogram and Differential Nonlinearity
#
#
#
#
#
#
#
#
#
#
#
#
#
#
#
Frequency (MHz)
:-;0<:*,;=0<*,;#+>
/
'*,&!!
Amplitude Relative to Full Scale (dB)

Number of Occurrences
Digital Output Code

"
#

DNL (LSB's)
Digital Output Code
®®
ADS-919
MECHANICAL DIMENSIONS INCHES (mm)
0.200 MAX.
(5.080)
0.235 MAX.
(5.969)
0.600 ±0.010
(15.240)
0.80 MAX.
(20.32)
0.100 TYP.
(2.540)
0.100
(2.540)
0.018 ±0.002
(0.457)
0.100
(2.540)
0.040
(1.016)
1.31 MAX.
(33.27)
112
13
24
1.100
(27.940)
0.190 MAX.
(4.826)
0.010
(0.254)
+0.002
–0.001
SEATING
PLANE
0.025
(0.635)
Dimension Tolerances (unless otherwise indicated):
2 place decimal (.XX) ±0.010 (±0.254)
3 place decimal (.XXX) ±0.005 (±0.127)
Lead Material: Kovar alloy
Lead Finish: 50 microinches (minimum) gold plating
over 100 microinches (nominal) nickel plating
PIN 1 INDEX
ORDERING INFORMATION
MODEL OPERATING ANALOG
NUMBER TEMP. RANGE INPUT
ADS-919MC 0 to +70°C Unipolar (0 to +10V)
ADS-919MM –55 to +125°C Unipolar (0 to +10V)
ADS-919GC 0 to +70°C Unipolar (0 to +10V)
ADS-919GM –55 to +125°C Unipolar (0 to +10V)
ADS-929MC 0 to +70°C Bipolar (±5V)*
ADS-929MM –55 to +125°C Bipolar (±5V)*
ADS-929/883 –55 to +125°C Bipolar (±5V)*
ADS-929GC 0 to +70°C Bipolar (±5V)*
ADS-929GM –55 to +125°C Bipolar (±5V)*
24-Pin DDIP
Versions
ADS-919MC
ADS-919MM
ADS-929MC
ADS-929MM
ADS-929/883
24-Pin
Surface Mount
Versions
ADS-919GC
ADS-919GM
ADS-929GC
ADS-929GM
ACCESSORIES
ADS-B919/929 Evaluation Board (without ADS-919)
HS-24 Heat Sinks for all ADS-919/929 DDIP models
Receptacles for PC board mounting can be ordered through
AMP Inc. Part #3-331272-8 (Component Lead Socket), 24 required.
For MIL-STD-883 product specifications, contact DATEL.
* For information, see ADS-929 data sheet.
0.80 MAX.
(20.32)
0.015
(0.381)
MAX. radius
for any pin
1.31 MAX.
(33.02)
0.100 TYP.
(2.540)
0.100
(2.540)
0.190 MAX.
(4.826)
0.040
(1.016)
0.020 TYP.
(0.508)
0.020
(0.508)
24 13
121
PIN 1
INDEX
0.130 TYP.
(3.302)
Dimension Tolerances (unless otherwise indicated)
:
2 place decimal (.XX) ±0.010 (±0.254)
3 place decimal (.XXX) ±0.005 (±0.127)
Lead Material: Kovar alloy
Lead Finish: 50 microinches (minimum) gold plating
over 100 microinches (nominal) nickel plating
0.060 TYP.
(1.524)
0.010 TYP.
(0.254)
DATEL makes no represent ation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. The descriptions contained herein
do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. Specifications are subject to change without notice. The DATEL logo is a registered DATEL, Inc. trademark.
ISO 9001
I
SO 9001
%
DS-0319B 9/04
DATEL, Inc. 11 Cabot Boulevard, Mansfield, MA 02048-1151
Tel: (508) 339-3000 (800) 233-2765 Fax: (508) 339-6356
Internet: www.datel.com E-mail:sales@datel.com
DA TEL (UK) L TD. Tadley , England Tel: (01256)-880444
DATEL S.A.R.L. Montigny Le Bretonneux, France Tel: 1-34-60-01-01
DATEL GmbH München, Germany Tel: 89-544334-0
DATEL KK Tokyo, Japan Tel: 3-3779-1031, Osaka Tel: 6-6354-2025
®®
A SUBSIDIARY OF C&D TECHNOLOGIES