FEATURES
• 16-bit resolution
• 1MHz minimum sampling rate
• No missing codes over full military temperature range
• Very low power, 1.25 Watts
• Small, 32-pin, side-brazed, ceramic TDIP
• Edge-triggered
• Excellent performance
• Ideal for both time and frequency-domain applications
• Low cost
military (–55 to +125°C) operating temperature ranges. A
proprietary, auto-calibrating, error-correcting circuit enables
the device to achieve specified performance over the full
military temperature range.
ADS-937
16-Bit, 1MHz, Low-Power
Sampling A/D Converters
GENERAL DESCRIPTION
The low-cost ADS-937 is a 16-bit, 1MHz sampling A/D con-
verter. This device accurately samples full-scale input signals
up to Nyquist frequencies with no missing codes. This feature,
combined with excellent signal-to-noise ratio (SNR) and total
harmonic distortion (THD), makes the ADS-937 the ideal
choice for both time-domain (CCD/medical imaging, scanners,
process control) and frequency-domain (radar, telecommunica-
tions, spectrum analysis) applications.
Packaged in a 32-pin, side-brazed, metal-sealed, ceramic
TDIP, the functionally complete ADS-937 contains a fast-
settling sample-hold amplifier, a subranging (two-pass) A/D
converter, an internal reference, timing/control logic, and error-
correction circuitry. Digital input and output levels are TTL.
ADS-937 only requires the rising edge of the start convert
pulse to operate.
Requiring ±15V and ±5V supplies, the ADS-937 typically
dissipates 1.25 Watts. The device is offered with both bipolar
(±5V) and unipolar (0 to –10V) analog input ranges. Models
are available for use in either commercial (0 to +70°C) or
INPUT/OUTPUT CONNECTIONS
Figure 1. ADS-937 Functional Block Diagram
1 ANALOG INPUT 32 BIT 1 (MSB)
2 ANALOG GROUND 31 BIT 2
3 UNIPOLAR 30 BIT 3
4 OFFSET ADJUST 29 BIT 4
5 +5V REFERENCE OUT 28 BIT 5
6 GAIN ADJUST 27 BIT 6
7 COMPENSATION 26 BIT 7
8 –15V SUPPLY 25 BIT 8
9 +15V SUPPLY 24 BIT 9
10 +5V ANALOG SUPPLY 23 BIT 10
11 –5V ANALOG SUPPLY 22 BIT 11
12 ANALOG GROUND 21 BIT 12
13 DIGITAL GROUND 20 BIT 13
14 +5V DIGITAL SUPPLY 19 BIT 14
15 EOC 18 BIT 15
16 START CONVERT 17 BIT 16 (LSB)
PIN FUNCTION PIN FUNCTION
REF
DAC
32 BIT 1 (MSB)
31 BIT 2
30 BIT 3
29 BIT 4
28 BIT 5
27 BIT 6
26 BIT 7
25 BIT 8
24 BIT 9
23 BIT 10
22 BIT 11
21 BIT 12
20 BIT 13
19 BIT 14
18 BIT 15
17 BIT 16 (LSB)
TIMING AND
CONTROL LOGIC
ANALOG INPUT 1
START CONVERT 16
EOC 15
–
+
S/H
BUFFER
DI
GI
TA
L
CO
RR
EC
TI
ON
L
OG
IC
FLASH
ADC
1
FLASH
ADC
2
Σ
AMP
GAIN
CIRCUIT
COMPENSATION 7
+5V REFERENCE OUT 5
10
+5V ANALOG
SUPPLY
11
–5V ANALOG
SUPPLY
2, 12
ANALOG
GROUND
14
+5V DIGITAL
SUPPLY
9
+15V
SUPPLY
8
–15V
SUPPLY
13
DIGITAL
GROUND
OFFSET ADJUST 4
UNIPOLAR 3
GAIN ADJUST 6
DATEL, Inc., Mansfield, MA 02048 (USA) • Tel: (508) 339-3000, (800) 233-2765 Fax: (508) 339-6356 • Email: sales@datel.com • Internet: www.datel.com
® ®