FEATURES
G183 18-bit resolution
G183 500kHz minimum sampling rate
G183 No missing codes over full military temperature range
G183 Very low power, 1.45 Watts
G183 Small, 32-pin, side-brazed, ceramic TDIP
G183 Edge-triggered
G183 Excellent performance
G183 Ideal for both time and frequency-domain applications
G183 Low cost
operating temperature ranges. A proprietary, auto-calibrating,
error-correcting circuit enables the device to achieve specified
performance over the full military temperature range.
PRELIMINARY PRODUCT DATA
ADS-950
18-Bit, 500kHz, Low-Power
Sampling A/D Converters
GENERAL DESCRIPTION
The low-cost ADS-950 is an 18-bit, 500kHz sampling A/D
converter. 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-950 the
ideal choice for both time-domain (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-950 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, and
the ADS-950 only requires the rising edge of the start convert
pulse to operate.
Requiring ±15V and ±5V supplies, the ADS-950 typically
dissipates 1.45 Watts. The device is offered with a bipolar
(±5V) analog input range. Models are available for use in
either commercial (0 to +70°C) or military (–55 to +125°C)
INPUT/OUTPUT CONNECTIONS
Figure 1. ADS-950 Functional Block Diagram
1 BIT 2 32 BIT 3
2 BIT 1 (MSB) 31 BIT 4
3 ANALOG GROUND 30 BIT 5
4 ANALOG INPUT 29 BIT 6
5 +5V REFERENCE OUT 28 BIT 7
6 GAIN ADJUST 27 BIT 8
7 COMPENSATION 26 BIT 9
8 –15V SUPPLY 25 BIT 10
9 +15V SUPPLY 24 BIT 11
10 +5V ANALOG SUPPLY 23 BIT 12
11 –5V ANALOG SUPPLY 22 BIT 13
12 ANALOG GROUND 21 BIT 14
13 DIGITAL GROUND 20 BIT 15
14 +5V DIGITAL SUPPLY 19 BIT 16
15 EOC 18 BIT 17
16 START CONVERT 17 BIT 18 (LSB)
PIN FUNCTION PIN FUNCTION
DATEL, Inc., Mansfield, MA 02048 (USA) G32G183 Tel: (508) 339-3000, (800) 233-2765 Fax: (508) 339-6356 G183 Email: sales@datel.com G183 Internet: www.datel.com
®®
REF
DAC
2 BIT 1 (MSB)
1 BIT 2
32 BIT 3
31 BIT 4
30 BIT 5
29 BIT 6
28 BIT 7
27 BIT 8
26 BIT 9
25 BIT 10
24 BIT 11
23 BIT 12
22 BIT 13
21 BIT 14
20 BIT 15
19 BIT 16
18 BIT 17
17 BIT 18 (LSB)
TIMING AND
CONTROL LOGIC
ANALOG INPUT 4
START CONVERT 16
EOC 15
–
+
S/H
BUFFER
DI
GI
TAL
CORRECTI
O
N L
OGI
C
FLASH
ADC
1
FLASH
ADC
2
G53
AMP
GAIN
CIRCUIT
COMPENSATION 7
+5V REFERENCE OUT 5
10
+5V ANALOG
SUPPLY
11
–5V ANALOG
SUPPLY
3, 12
ANALOG
GROUND
14
+5V DIGITAL
SUPPLY
9
+15V
SUPPLY
8
–15V
SUPPLY
13
DIGITAL
GROUND
GAIN ADJUST 6