Figure 1. ADS-932 Functional Block Diagram
3-STATE
OUTPUT REGISTER
29 BIT 1 (MSB)
28 BIT 1 (MSB)
27 BIT 2
26 BIT 3
25 BIT 4
24 BIT 5
23 BIT 6
22 BIT 7
21 BIT 8
20 BIT 9
19 BIT 10
18 BIT 11
17 BIT 12
16 BIT 13
15 BIT 14
14 BIT 15
13 BIT 16 (LSB)
TIMING AND
CONTROL LOGIC
GAIN ADJUST 6
+3.2V REF. OUT 1
OFFSET ADJUST 5
EOC 32
ANALOG GROUND 4, 36
DIGITAL GROUND 7, 30
+5V DIGITAL SUPPLY 31
–5V SUPPLY 37
+5V ANALOG SUPPLY 38
NO CONNECTION 39, 40
CUSTOM GATE ARRAY
POWER and GROUNDING
2-PASS ANALOG-TO-DIGITAL CONVERTER
S/H
GAIN
ADJUST
CKT.
OFFSET
ADJUST
CKT.
PRECISION
+3.2V REFERENCE
ANALOG INPUT 3
START CONVERT 12
COMP. BITS 35
10 FSTAT1
11 FSTAT2
8 FIFO/DIR
9 FIFO/READ
34 OUTPUT ENABL
E
33 OVERFLOW
BLOCK DIAGRAM
The low-cost ADS-932 is a 16-bit, 2MHz sampling
A/D converter. This device accurately samples full-scale
input signals up to Nyquist frequencies with no missing
codes. The dynamic performance of the ADS-932 has
been optimized to achieve a signal-to-noise ratio (SNR)
of 87dB and a total harmonic distortion (THD) of –88dB.
Packaged in a 40-pin TDIP, the functionally complete
ADS-932 contains a fast-settling sample-hold amplifi er, a
subranging (two-pass) A/D converter, an internal reference,
timing/control logic, and error-correction circuitry. Digital
input and output levels are TTL. The ADS-932 only requires
the rising edge of the start convert pulse to operate.
Requiring only ±5V supplies, the ADS-932 dis-
sipates 1.85 Watts. The device is offered with a bipolar
(±2.75V) analog input range or a unipolar (0 to –5.5V)
input range. Models are available for use in either com-
mercial (0 to +70°C or –40 to +100°C) or military (–55
to +125°C) operating temperature ranges. A proprietary,
auto-calibrating, error-correcting circuit enables the
device to achieve specifi ed performance over the full
HI-REL temperature range. Typical applications include
medical imaging, radar, sonar, communications and
instrumentation.
PRODUCT OVERVIEW INPUT/OUTPUT CONNECTIONS
PIN FUNCTION PIN FUNCTION
1 +3.2V REF. OUT 40 NO CONNECTION
2 UNIPOLAR 39 NO CONNECTION
3 ANALOG INPUT 38 +5V ANALOG SUPPLY
4 ANALOG GROUND 37 –5V SUPPLY
5 OFFSET ADJUST 36 ANALOG GROUND
6 GAIN ADJUST 35 COMP. BITS
7 DIGITAL GROUND 34 OUTPUT ENABLE
8 FIFO/DIR 33 OVERFLOW
9 FIFO READ 32 EOC
10 FSTAT1 31 +5V DIGITAL SUPPLY
11 FSTAT2 30 DIGITAL GROUND
12 START CONVERT 29 BIT 1 (MSB)
13 BIT 16 (LSB) 28 BIT 1 (MSB)
14 BIT 15 27 BIT 2
15 BIT 14 26 BIT 3
16 BIT 13 25 BIT 4
17 BIT 12 24 BIT 5
18 BIT 11 23 BIT 6
19 BIT 10 22 BIT 7
20 BIT 9 21 BIT 8
FEATURES
■ 16-bit resolution
■ 2MHz sampling rate
■ Functionally complete
■ No missing codes over full HI-REL temperature
range
■ Edge-triggered
■ ±5V supplies, 1.85 Watts
■ Small, 40-pin, ceramic TDIP
■ 87dB SNR, –88dB THD
■ Ideal for both time and frequency-domain
applications
®®
DATEL • 11 Cabot Boulevard, Mansfi eld, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: help@datel.com
ADS-932
16-Bit, 2 MHz Sampling A/D Converters
MDA_ADS-932.B03 Page 1 of 9
PHYSICAL/ENVIRONMENTAL
PARAMETERS MIN. TYP. MAX. UNITS
Operating Temp. Range, Case
ADS-932MC 0 — +70 °C
ADS-932ME –40 — +100 °C
ADS-932MM –55 — +125 °C
Thermal Impedance
θjc — 4 — °C/Watt
θca — 18 — °C/Watt
Storage Temperature Range –65 — +150 °C
Package Type 40-pin, metal-sealed, ceramic TDIP
Weight 0.56 ounces (16 grams)
ABSOLUTE MAXIMUM RATINGS
PARAMETERS LIMITS UNITS
+5V Supply (Pins 31, 38) 0 to +6 Volts
–5V Supply (Pin 37) 0 to –6 Volts
Digital Inputs (Pin 8, 9, 12, 34, 35) –0.3 to +VDD +0.3 Volts
Analog Input (Pin 3)
Bipolar ±2.75 Volts
Unipolar 0 to -5.5 Volts
Lead Temperature (10 seconds) +300 °C
+25°C 0 TO +70°C –55 TO +125°C
–40 TO +100°C
ANALOG INPUTS MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS
Input Voltage Range
Unipolar — 0 to –5.5 — — 0 to –5.5 — — 0 to –5.5 — Volts
Bipolar — ±2.75 — — ±2.75 — — ±2.75 — Volts
Input Resistance (pin 3) 655 687 — — 685 — — 685 —
Input Resistance (pin 2) 418 426 — — 400 — — 400 —
Input Capacitance — 10 15 — 10 15 — 10 15 pF
DIGITAL INPUTS
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" ➁ — — –20 — — –20 — — –20 µA
Start Convert Positive Pulse Width ➂ 40 250 — 40 250 — 40 250 — ns
STATIC PERFORMANCE
Resolution — 16 — — 16 — — 16 — Bits
Integral Nonlinearity — ±1.0 — — ±1.5 — — ±2.0 — LSB
Differential Nonlinearity (fin = 10kHz) –0.95 ±0.5 +1.0 –0.95 ±0.5 +1.0 –0.95 ±0.5 +1.5 LSB
Full Scale Absolute Accuracy — ±0.1 ±0.3 — ±0.15 ±0.5 — ±0.5 ±0.8 %FSR
Bipolar Zero Error (Tech Note 2) — ±0.1 ±0.2 — ±0.2 ±0.4 — ±0.5 ±0.9 %FSR
Bipolar Offset Error (Tech Note 2) — ±0.1 ±0.3 — ±0.2 ±0.5 — ±0.4 ±0.9 %FSR
Gain Error (Tech Note 2) — ±0.1 ±0.3 — ±0.15 ±0.5 — ±0.5 ±0.9 %FSR
No Missing Codes (fin = 10kHz) 16 — — 16 — — 16 — — Bits
DYNAMIC PERFORMANCE
Peak Harmonics (–0.5dB)
dc to 500kHz — –90 –81 — –90 –81 — –88 –80 dB
500kHz to 1MHz — –90 –81 — –90 –81 — –88 –74 dB
Total Harmonic Distortion (–0.5dB)
dc to 500kHz — –88 –80 — –88 –80 — –85 –78 dB
500kHz to 1MHz — –87 –80 — –87 –80 — –84 –73 dB
Signal–to–Noise Ratio
(w/o distortion, –0.5dB)
dc to 500kHz 83 87 — 83 87 — 80 85 — dB
500kHz to 1MHz 82 86 — 82 86 — 80 84 — dB
Signal-to-Noise Ratio ➃
(& distortion, –0.5dB)
dc to 500kHz 79 84 — 79 84 — 76 82 — dB
500kHz to 1MHz 78 84 — 78 84 — 73 82 — dB
Two-tone Intermodulation
Distortion (fin = 200kHz,
240kHz, fs = 2MHz, –0.5dB) — –89 — — –89 — — –89 — dB
Noise — 83 — — 83 — — 83 — µVrms
Input Bandwidth (–3dB)
Small Signal (–20dB input) — 7.8 — — 7.8 — — 7.8 — MHz
Large Signal (–0.5dB input) — 7.1 — — 7.1 — — 7.1 — MHz
Feedthrough Rejection (fin = 1MHz) — 90 — — 90 — — 90 — dB
Slew Rate — ±77 — — ±77 — — ±77 — V/µs
Aperture Delay Time — +8 — — +8 — — +8 — ns
Aperture Uncertainty — 5 — — 5 — — 5 — ps rms
S/H Acquisition Time
(to ±0.001%FSR, 5.5V step) 200 225 — 200 225 — 200 225 — ns
Overvoltage Recovery Time ➄ — 250 500 — 250 500 — 250 500 ns
A/D Conversion Rate 2 — — 2 — — 2 — — MHz
FUNCTIONAL SPECIFICATIONS
(TA = +25°C, VCC = -5V +VDD = +5V, 2MHz sampling rate, and a minimum 3 minute warmup ➀ unless otherwise specifi ed.)
®®
DATEL • 11 Cabot Boulevard, Mansfi eld, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: help@datel.com
ADS-932
16-Bit, 2 MHz Sampling A/D Converters
MDA_ADS-932.B03 Page 2 of 9
TECHNICAL NOTES
+25°C 0 to +70°C –55 to +125°C
–40 TO +100°C
ANALOG OUTPUT MIN. TYP. MAX. MIN. TYP. MAX. MIN. TYP. MAX. UNITS
Internal Reference
Voltage 3.15 +3.2 3.25 3.15 +3.2 3.25 3.15 +3.2 3.25 Volts
Drift — ±30 — — ±30 — — ±30 — ppm/°C
External Current — 5 — — 5 — — 5 — mA
DIGITAL 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 ENABLE to
Output Data Valid — — 20 — — 20 — — 20 ns
Output Coding Straight Binary, Complementary Binary, Complementary Offset Binary, Complementary Two's Complement, Offset Binary, Two's Complement
POWER REQUIREMENTS
Power Supply Ranges ➅
+5V Supply +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 +4.9 +5.0 +5.25 Volts
–5V Supply –4.75 –5.0 –5.25 –4.75 –5.0 –5.25 –4.9 –5.0 –5.25 Volts
Power Supply Currents
+5V Supply — +225 260 — +225 260 — +225 260 mA
–5V Supply –140 –135 — –140 –135 — –140 –135 — mA
Power Dissipation — 1.85 2.0 — 1.85 2.0 — 1.85 2.0 Watts
Power Supply Rejection — — ±0.07 — — ±0.07 — — ±0.07 %FSR/%V
Footnotes:
➀ 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 operating the device in the unipolar mode.
➁ When COMP. BITS (pin 35) is low, logic loading "0" will be –350μA.
➂ A 2MHz clock with a positive pulse width is used for all production testing. See
Timing Diagram for more details.
40ns < Start Pulse < 175ns or 280ns < Start Pulse < 460ns
(SNR + Distortion) – 1.76 + 20 log Full Scale Amplitude
Actual Input Amplitude
6.02
➃ Effective bits is equal to:
➄ This is the time required before the A/D output data is valid once the analog input
is back within the specifi ed range. This time is only guaranteed if the input does not
exceed ±4.75V (bipolar) or +2 to –7.5V (unipolar).
➅ The minimum supply voltages of +4.9V and –4.9V for ±VDD are required for –55°C
operation only. The minimum limits are +4.75V and –4.75V when operating at
+125°C.
1. Obtaining fully specifi ed performance from the ADS-932 requires care-
ful 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 (4, 7, 30 and 36) directly to a
large analog ground plane beneath the package.
Bypass all power supplies and the +3.2V reference output to ground with
4.7F tantalum capacitors in parallel with 0.1F ceramic capacitors. Locate
the bypass capacitors as close to the unit as possible.
2. The ADS-932 achieves its specifi ed accuracies without the need for exter-
nal calibration. If required, the device's small initial offset and gain errors
can be reduced to zero using the adjustment circuitry shown in Figure 2.
When using this circuitry, or any similar offset and gain calibration hard-
ware, make adjustments following warmup. To avoid interaction, always
adjust offset before gain. Tie pins 5 and 6 to ANALOG GROUND (pin 4) if not
using offset and gain adjust circuits.
3. Pin 35 (COMP. BITS) is used to select the digital output coding format of the
ADS-932 (see Tables 2a and 2b). When this pin has a TTL logic "0" applied,
it complements all of the ADS-932's B1-B16 & B1outputs.
Pin 35 is TTL compatible and can be directly driven with digital logic in
applications requiring dynamic control over its function. There is an internal
pull-up resistor on pin 35 allowing it to be either connected to +5V or left
open when a logic "1" is required.
4. To enable the three-state outputs, connect OUTPUT ENABLE (pin 34) to a
logic "0" (low). To disable, connect pin 34 to a logic "1" (high).
5. Applying a start convert pulse while a conversion is in progress (EOC =
logic "1") will initiate a new and probably inaccurate conversion cycle. Data
from both the interrupted and subsequent conversions will be invalid.
6. Do not enable/disable or complement the output bits or read from the FIFO
during the conversion process (from the rising edge of EOC to the falling
edge of EOC).
7. The OVERFLOW bit (pin 33) switches from 0 to 1 when the input voltage
exceeds that which produces an output of all 1’s or when the input equals
or exceeds the voltage that produces all 0’s. When COMP BITS is activated,
the above conditions are reversed.
8. When confi guring the ADS-932 for the unipolar mode, Pin 1 (+3.2V REF.)
should be connected to Pin 2 (Unipolar) through a non-inverting op-amp.
For precision DC applications an OP- 07 type amplifi er is recommended,
while AC applications requiring the lowest level of harmonic distortion
should consider the AD9631.
When confi guring the ADS-932 for the bipolar mode, Pin 2 (Unipolar) should
be physically disconnected from the surrounding circuitry. This will help
prevent noise from coupling into the A/D.
®®
DATEL • 11 Cabot Boulevard, Mansfi eld, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: help@datel.com
ADS-932
16-Bit, 2 MHz Sampling A/D Converters
MDA_ADS-932.B03 Page 3 of 9
INTERNAL FIFO OPERATION
The ADS-932 contains an internal, user-initiated, 18-bit, 16-word FIFO
memory. Each word in the FIFO contains the 16 data bits as well as the MSB
and OVERFLOW bits. Pins 23 (FIFO/DIR) and 10 (FIFO READ) control the FIFO's
operation. The FIFO's status can be monitored by reading pins 10 (FSTAT1)
and 11 (FSTAT2).
When pin 8 (FIFO/DIR) has a logic "1" applied, the FIFO is inserted into the
digital data path. When pin 8 has a logic "0" applied, the FIFO is transpar-
ent, and the output data goes directly to the output three-state register (whose
operation is controlled by pin 34 (ENABLE). Read and write commands to the
FIFO are ignored when the ADS-932 is operated in the "direct" mode. It takes a
maximum of 20ns to switch the FIFO in or out of the ADS-932's digital data path.
FIFO WRITE and READ Modes
Once the FIFO has been enabled (pin 8 high), digital data is automatically
written to it, regardless of the status of FIFO READ (pin 9). Assuming the FIFO
is initially empty, it will accept data (18-bit words) from the next 16 consecu-
tive A/D conversions. As a precaution, pin 9 (which controls the FIFO's READ
function) should not be low when data is fi rst written to an empty FIFO.
When the FIFO is initially empty, digital data from the fi rst conversion (the
"oldest" data) appears at the output of the FIFO immediately after the fi rst
conversion has been completed and remains there until the FIFO is read.
If the output three-state register has been enabled (logic "0" applied to pin
34), data from the fi rst conversion will appear at the output of the ADS-932.
Attempting to write a 17th word to a full FIFO will result in that data, and any
subsequent conversion data, being lost.
Once the FIFO is full (indicated by FSTAT1 and FSTAT2 both equal to "1"), it
can be read by dropping the FIFO READ line (pin 9) to a logic "0" and then
applying a series of 15 rising edges to the read line. Since the fi rst data word
is already present at the FIFO output, the fi rst read command (the fi rst rising
edge applied to FIFO READ) will bring data from the second conversion to the
output. Each subsequent read command/rising edge brings the next word
to the output lines. After the 15th rising edge brings the 16th data word to
the FIFO output, the subsequent falling edge on READ will update the status
outputs (after a 20ns maximum delay) to FSTAT1 = 0, FSTAT2 = 1 indicating
that the FIFO is empty.
If a read command is issued after the FIFO empties, the last word (the 16th
conversion) will remain present at the outputs.
FIFO Reset Feature
At any time, the FIFO can be reset to an empty state by putting the ADS-932
into its "direct" mode (logic "0" applied to pin 8, FIFO/DIR) and also applying
a logic "0" to the FIFO READ line (pin 9). The empty status of the FIFO will be
indicated by FSTAT1 going to a "0" and FSTAT2 going to a "1". The status
outputs change 40ns after applying the control signals.
FIFO Status, FSTAT1 and FSTAT2
Monitor the status of the data in the FIFO by reading the two status pins,
FSTAT1 (pin 10) and FSTAT2 (pin 11).
CONTENTS FSTAT1 FSTAT2
Empty (0 words) 0 1
<half full (≤7 words) 0 0
half-full or more (≥8 words) 1 0
Full (16 words) 1 1
Table 1. FIFO Delays
DELAY PIN TRANSITION MIN. TYP. MAX. UNITS
Direct mode to FIFO enabled 8 – 10 20 ns
FIFO enabled to direct mode 8 – 10 20 ns
FIFO READ to output data valid 9 – – 40 ns
FIFO READ to status update when changing
from <half full (1 word) to empty 9––20ns
FIFO READ to status update when changing
from thalf full (8 words) to <half full (7 words) 9 – – 110 ns
FIFO READ to status update when changing
from full (16 words) to thalf full (15 words) 9 – – 190 ns
Falling edge of EOC to status update when writing
first word into empty FIFO 32 – – 190 ns
Falling edge of EOC to status update when
changing FIFO from <half full (7 words) to 32 – – 110 ns
thalf full (8 words)
Falling edge of EOC to status update when filling
FIFO with 16th word 32 – – 28 ns
1
0
0
1
1
0
0
1
0
1
0
1
0
1
1
0
1
0
®®
DATEL • 11 Cabot Boulevard, Mansfi eld, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: help@datel.com
ADS-932
16-Bit, 2 MHz Sampling A/D Converters
MDA_ADS-932.B03 Page 4 of 9
CALIBRATION PROCEDURE
Connect the converter per Figure 2. Any offset/gain calibration procedures
should not be implemented until the device is fully warmed up. To avoid
interaction, adjust offset before gain. The ranges of adjustment for the
circuits in Figure 2 are guaranteed to compensate for the ADS-932’s initial
accuracy errors and may not be able to compensate for additional system
errors.
A/D converters are calibrated by positioning their digital outputs exactly
on the transition point between two adjacent digital output codes. This is
accomplished by connecting LED's to the digital outputs and performing
adjustments until certain LED's "fl icker" 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-932, offset adjusting is normally accomplished when the ana-
log input is 0 minus ½ LSB (–42V). See Table 2b for the proper bipolar
output coding.
Gain adjusting is accomplished when the analog input is at nominal full
scale minus 1½ LSB's (+2.749874V).
Note: Connect pin 5 to ANALOG GROUND (pin 4) for operation without
zero/offset adjustment. Connect pin 6 to pin 4 for operation without gain
adjustment.
Zero/Offset Adjust Procedure
1. Apply a train of pulses to the START CONVERT input (pin 12) so that the
converter is continuously converting.
2. For unipolar or bipolar zero/offset adjust, apply –42V to the ANALOG
INPUT (pin 3).
3. For bipolar inputs, adjust the offset potentiometer until the code fl ickers
between 1000 0000 0000 0000 and 0111 1111 1111 1111 with pin 35
tied high (complementary offset binary) or between 0111 1111 1111 1111
and 1000 0000 0000 0000 with pin 35 tied low (offset binary). For unipo-
lar inputs, adjust the offset potentiometers until all output bits are 0's and
the LSB fl ickers between 0 and 1 with Pin 35 tied high (straight binary) or
until all bits are 1's and the LSB fl ickers between 0 and 1 with pin 35 tied
low (complementary binary).
4. Two's complement coding requires using BIT 1 (MSB) (pin 29). With pin 35
tied low, adjust the trimpot until the output code fl ickers between all 0’s
and all 1’s.
Gain Adjust Procedure
1. Apply +2.749874V to the ANALOG INPUT (pin 3).
2. For bipolar inputs, adjust the gain potentiometer until all output bits are 0’s
and the LSB fl ickers between a 1 and 0 with pin 35 tied high (comple-
mentary offset binary) or until all output bits are 1’s and the LSB fl ickers
between a 1 and 0 with pin 35 tied low (offset binary).
3. Two's complement coding requires using BIT 1 (MSB) (pin 29). With pin
35 tied low, adjust the gain trimpot until the output code fl ickers equally
between 0111 1111 1111 1111 and 0111 1111 1111 1110.
Table 2a. Setting Output Coding Selection (Pin 35)
OUTPUT FORMAT PIN 35 LOGIC LEVEL
Complementary Offset Binary 1
Offset Binary 0
Complementary Two’s Complement (Using MSB, pin 29) 1
Two’s Complement (Using MSB, pin 29) 0
Straight Binary 1
Complementary Binary 0
Figure 2. Bipolar Connection Diagram
ADS-932
20k:
33
32
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
OVERFLOW
EOC
BIT 1 (MSB)
BIT 1 (MSB)
BIT2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
BIT 8
BIT 9
BIT 10
BIT 11
BIT 12
BIT 13
BIT 14
BIT 15
BIT 16 (LSB)
ANALOG
GROUND
DIGITAL
GROUND
0.1F
4.7F
0.1FCOMP. BITS
4.7F
+3.2V
REF. OUT
FIFO READ
31
7, 30
35
1
9
+5V
DIGITAL
–5V+5V
OFFSET
ADJUST
GAIN
ADJUST
5
6
3
0.1F
4.7F
4, 36
37
0.1F
4.7F
38
++
20k:
–5V+5V
–5V
+5V ANALOG
12START CONVERT
ANALOG INPUT
34 ENABLE
8 FIFO/DIR
10 FSTAT1
11 FSTAT2
+5V
+5V
+5V
–5V
UNIPOLAR
C
ONNECT for UNIPOLAR MODE
2
6.8F
®®
DATEL • 11 Cabot Boulevard, Mansfi eld, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: help@datel.com
ADS-932
16-Bit, 2 MHz Sampling A/D Converters
MDA_ADS-932.B03 Page 5 of 9
THERMAL REQUIREMENTS
All DATEL sampling A/D converters are fully characterized and specifi ed 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 fi gures for each
device are listed in their respective specifi cation tables.
These devices do not normally require heat sinks, however, standard precau-
tionary 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 fl ow
over the surface can greatly help reduce the package temperature.
Figure 3. ADS-932 Timing Diagram
This device has three pipeline delays. Four start convert pulses (clock cycles) must be applied for valid data
from the first conversion to appear at the output of the A/D.
START
CONVERT
INTERNAL S/H
NN+1
Acquisition Time
225ns typ.
20ns typ.
EOC
75ns typ.
OUTPUT
DATA Data N-4 Valid Data N-2 Valid
Invalid
Data
Data N-3 Valid
20ns typ.
N+2
Data N-1 Valid
440ns typ.
60ns typ. Invalid
Data
Notes:
100ns typ.
N+3
275ns typ.
45ns typ.
260ns typ.
Conversion Time
Hold
The start convert positive pulse width must be between either 40 and 175nsec or 280 and 460nsec
(when sampling at 2MHz) to ensure proper operation. For sampling rates lower than 2MHz, the start pulse
can be wider than 460nsec, however a minimum pulse width low of 40nsec should be maintained. A 2MHz
clock with a 100nsec
p
ositive
p
ulse width is used for all
p
roduction testin
g
.
Scale is approximately 50ns per division. fs = 2MHz.1.
2.
3.
Figure 4. FFT Analysis of ADS-932
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
–140
–150
–160
–170
0 100 200 300 400 500 600 700 800 900 1000
Frequency (kHz)
(
fs = 2MHz, fin = 975kHz, Vin = –0.5dB, 16,384-
p
oint FFT
)
Amplitude Relative to Full Scale (dB)
®®
DATEL • 11 Cabot Boulevard, Mansfi eld, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: help@datel.com
ADS-932
16-Bit, 2 MHz Sampling A/D Converters
MDA_ADS-932.B03 Page 6 of 9
Figure 5. ADS-932 Evaluation Board Schematic
20k
R4
1
23
U2
9
8
7
6
5
4
3
2
11 1
19
18
17
16
15
14
13
12
0201
74HCT573
UUT
B6
B7
B8
B9
B10
B11
+5VD
DGND
MSB
B2
B3
B4
B5
B12
B13
B14
B15
LSB
START
FSTAT2
FSTAT1
NC
NC
+5VA
-5VA
AGND
COMP
ENABLE
OF
EOC
READ
FIFO/DIR
DGND
GAIN
OFFSET
AGND
ANA IN
+3.2VREF
U6
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20 21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
U1
12
11
13 8
9
10
74HCT74
2.2F
C13
33
31
29
27
25
23
21
19
17
15
13
11
9
7
5
3
1
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
P1
FST2
START
FST1
B16
FIF/DIRB15
READB14 N.C.
B13
COMPLIMB12
ENABLEB11
DGNDB10
DGNDB9
DGNDB8
DGNDB7
DGNDB6
DGNDB5
DGNDB4
EOCB3
OVRFLWB2
B1B MSBB1(MSB)
2.2F
C11
0.1F
C20
U4
9
8
7
6
5
4
3
2
11 1
19
18
17
16
15
14
13
12
0201
74HCT573
0.1F
C15
33pF
C10
1
2
0.1F
C18
0.1F
C3
2.2F
C1
2.2F
C14
2.2F
C2
2.2F
C9
SG8
SG7
2.2F
C12 2.2F
C21
R2
R1
3.3k
R3 1
2
U1
2
3
1
6
5
4
74HCT74
SG9
SG6
2.2F
C4
20mH
L4
AR1
2
34
6
7
0.1F
C5
20mH
L3
U3
9
8
7
6
5
4
3
2
11 1
19
18
17
16
15
14
13
12
0201
74HCT573
SG4
SG3
X1
1
78
14
2MHZ
SG2
74HC86
C6
2.2F
20mH
L2
0.1F
C19
J5
P2 1
23
45
67
89
10 11
12 13
14 15
16 17
18 19
20 21
22 23
24 25
26
50
R6
SG5
12
13 11
74HC86
U5
4
5
6
J2
20mH
L1
74HC86
B2
2
J3
0.1F
C16
0.1F
C17
2.2F
C7
B1
1
J4
J1
0.1F
C8
SG1
B3
COMP
ENABLE
+5VA
+5VA +5VA
+5VA
+5VA
+5VA
+5VA
+5VF
+5VF
+5VF
+5VF
+5VF
+5VF
+5VF
FIF
FIF
RD
RD
START
CONVERT
B2
AB9
AB9
+15V
+15V
EOC
AB8
AB8
AB1
AB1
AB2
AB2
AB3
AB3
AB4
AB4
AB5
AB5
AB6
AB6
AB7
AB7
AB16
AB16
AB15
AB15
AB14
AB14
AB13
AB13
AB12
AB12
AB11
AB11
01BA01BA
AB10
FIFO/DIR
READ
COMPLIM
B15
B14
FST2
OVRFLW
B1
+5VD +5VD
+5VD
+5VD
+5VD
+5VD
B4
B5
B6
B7
B1B MSB
B13
B16
B8
B12
B11
B10
B9
–15V
–15V
AGND AGND AGND AGND
AGND
AGND
AGND
AGND
AGND
AGND
AGND
AGND
AGND
–5VA –5VA –5VA
–5VA
–5VA
–5VA
–5VA
DGND
N
DDGND
DGND
DGND
DGND
DGND
DGND
DGNDDGND
DGND
DGND
DGND
DGND DGND
DGND
DGND
DGND
DGND
DGND
DGND
START CONVERT
ANALOG INPUT
OPTION
AMPLIFIER
321
7
14
7
(LSB)
GAIN ADJUST
OFFSET
ADJUST
321
1
1
(MSB)
(LSB)
14
+5VF +5VF
COMP
ADS-932 EVALUATION BOARD
20k
R5
1
23
+5VA
–5VA
U5
2
3
1
U5
9
8
10
74HC86
FST1
U5
32
32
32
1
DGND
0.1F
0.1F
AGND
MSB
®®
DATEL • 11 Cabot Boulevard, Mansfi eld, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: help@datel.com
ADS-932
16-Bit, 2 MHz Sampling A/D Converters
MDA_ADS-932.B03 Page 7 of 9
COMP. BINARY
UNIPOLAR
SCALE
INPUT RANGE 0 to
0 to –5.5V
INPUT RANGE
±2.75V
BIPOLAR
SCALE
MSB LSB MSB LSB MSB LSB MSB LSB
–FS +1 LSB –5.499916 1111 1111 1111 1111 0000 0000 0000 0000 0111 1111 1111 1111 1000 0000 0000 0000 +2.749916 +FS –1 LSB
–FS +1 1/2 LSB –5.499874 LSB "1" to "0" LSB "0" to "1" LSB "1" to "0" LSB "0" to "1" +2.749874 +FS –1 1/2 LSB
–7/8 FS –4.812500 1110 0000 0000 0000 0001 1111 1111 1111 0110 0000 0000 0000 1001 1111 1111 1111 +2.062500 +3/4 FS
–3/4 FS –4.125000 1100 0000 0000 0000 0011 1111 1111 1111 0100 0000 0000 0000 1011 1111 1111 1111 +1.375000 +1/2 FS
–1/2FS –2.750000 1000 0000 0000 0000 0111 1111 1111 1111 0000 0000 0000 0000 1111 1111 1111 1111 0.000000 0
–1/2FS –1/2LSB –2.749958 0111 1111 1111 1111 1000 000 000 0000 1111 1111 1111 1111 0000 0000 0000 0000 –0.000084 –1/2 LSB
–1/4FS –1.375000 0100 0000 0000 0000 1011 1111 1111 1111 1100 0000 0000 0000 0011 1111 1111 1111 –1.375000 –1/2 FS
–1/8FS –0.687500 0010 0000 0000 0000 1101 1111 1111 1111 1010 0000 0000 0000 0101 1111 1111 1111 –2.062500 –3/4 FS
–1 LSB –0.000084 0000 0000 0000 0001 1111 1111 1111 1110 1000 0000 0000 0001 0111 1111 1111 1110 –2.749916 –FS +1 LSB
–1/2LSB –0.000042 LSB "0" to "1" LSB "1" to "0" LSB "0" to "1" LSB "1" to "0" –2.749958 –FS + 1/2 LSB
0 0.000000 0000 0000 0000 0000 1111 1111 1111 1111 1000 0000 0000 0000 0111 1111 1111 1111 –2.750000 –FS
OFFSET BINARY COMP. TWO'S COMP. TWO'S COMP.
Table 2b. Output Coding
Table 3. Input Connections
INPUT RANGE INPUT PIN TIE TOGETHER
0 to –5.5V Pin 3 Pin 1 To Pin 2
±2.75V Pin 3 Pin 2 is No Connect
Figure 6. ADS-932 Histogram and Differential Nonlinearity
0.74
DNL (LSB's)
–0.56 0Codes
0Digital Output Code
Number of Occurrences
65,536
65,536
Figure 7. ADS-932 Grounded Input Histogram
This histogram represents the typical peak-to-peak noise
(including quantization noise) associated with the ADS-932.
0
4410
Digital Output Code
4000
3000
2000
1000
®®
DATEL • 11 Cabot Boulevard, Mansfi eld, MA 02048-1151 USA • Tel: (508) 339-3000 • www.datel.com • e-mail: help@datel.com
ADS-932
16-Bit, 2 MHz Sampling A/D Converters
MDA_ADS-932.B03 Page 8 of 9
MECHANICAL DIMENSIONS - INCHES (mm)
ORDERING INFORMATION
MODEL
NUMBER
OPERATING
TEMP. RANGE ACCESSORIES
ADS-932MC 0 to +70°C
ADS-B932
HS-40
Evaluation Board (without ADS-932)
Heat Sink for all ADS-932 models
ADS-932ME –40 to +100°C
ADS-932MM –55 to +125°C
Receptacles for PC board mounting can be ordered through AMP, Inc., Part # 3-331272-8 (Component
Lead Socket), 40 required. For MIL-STD-883 product, or surface mount packaging, contact DATEL.
PIN 1 INDEX
( ON TOP)
2.12/2.07
(53.85/52.58)
0.018 ±0.002
(0.457)
0.100 TYP.
(2.540)
0.110/0.090
(2.794/2.286) SEATING
PLANE
0.035/0.015
(0.889/0.381)
0.200/0.175
(5.080/4.445)
0.245 MAX.
(6.223)
0.210 MAX.
(5.334)
0.045/0.035
(1.143/0.889)
1.11/1.08
(28.20/27.43)
120
2140
1.900 ±0.008
(48.260)
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
0.015/0.009
(0.381/0.229)
0.900 ±0.010
(22.86) 0.110/0.090
(2.794/2.286
. makes no representation 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. Specifi cations are subject to change
without notice.
www.datel.com • e-mail: help@datel.com
®®
DATEL
11 Cabot Boulevard, Mansfi eld, MA 02048-1151 USA
ITAR and ISO 9001/14001 REGISTERED
ADS-932
16-Bit, 2 MHz Sampling A/D Converters
MDA_ADS-932.B03 Page 9 of 9