® ® ADS-926
14-Bit, 500kHz, Low-Power
Sampling A/D Converters
Figure 1. ADS-926 Functional Block Diagram
FEATURES
• 14-bit resolution
• 500kHz sampling rate
• Functionally complete; No missing codes
• Small 24-pin DDIP or SMT package
• Operates from ±15V or ±12V supplies
• Low power, 1.75 Watts maximum
• Samples up to Nyquist frequencies
• Outstanding dynamic performance
• Bipolar ±5V input range
GENERAL DESCRIPTION
The ADS-926 is a high-performance, 14-bit, 500kHz sampling
A/D converter. This device accurately samples full-scale input
signals up to Nyquist frequencies with no missing codes and
exhibits outstanding dynamic performance that surpasses
most 16-bit, 500kHz sampling A/D's. THD and SNR, for
example, are typically –90dB and 80dB when converting full-
scale input signals up to 100kHz.
Housed in a small 24-pin DDIP or SMT (gull-wing) package,
the functionally complete ADS-926 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-926
dissipates only 1.75W (1.6W for ±12V), maximum. The unit is
offered with a bipolar input (–5V to +5V). 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. Contact DATEL for information on
devices screened to MIL-STD-883.
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
RE
GI
ST
ER
RE
GI
ST
ER
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
DI
GI
TA
L C
OR
RE
CT
IO
N
LO
GI
C
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
S2
S1