®®
Figure 1. ADS-117 Functional Block Diagram
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
ADS-117
12-Bit, 2MHz, Low-Power
Sampling A/D Converters
FEATURES
• 12-bit resolution
• No missing codes
• 2MHz minimum throughput
• Functionally complete
• Small 24-pin DDIP
• Low-power, 1.6 Watts
• Three-state output buffers
• Samples to Nyquist frequencies
GENERAL DESCRIPTION
DATEL's ADS-117 is a functionally complete, 12-bit, 2MHz,
sampling A/D converter. Its standard, 24-pin, double-width
DIP contains a fast-settling sample-hold amplifier, a 12-bit
subranging (two-step) A/D converter, a precision reference,
three-state output register and all the timing and control logic
necessary to operate from a single start convert pulse. Digital
input and output levels are TTL.
Total harmonic distortion (THD) and signal-to-noise ratio
(including distortion) typically run –78dB and 70dB,
respectively, with full scale inputs up to 100kHz. The ADS-
117 requires ±15V and +5V power supplies and typically
consumes 1.6 Watts. Models are available for use in either
commercial (0 to +70°C) or military (–55 to +125°C) operating
temperature ranges.
INPUT/OUTPUT CONNECTIONS
PIN FUNCTION PIN FUNCTION
1 BIT 12 (LSB) 24 –15V SUPPLY
2 BIT 11 23 ANALOG GROUND
3 BIT 10 22 +15V SUPPLY
4 BIT 9 21 +10V REFERENCE
5 BIT 8 20 BIPOLAR
6 BIT 7 19 ANALOG INPUT
7 BIT 6 18 COMP BIN
8 BIT 5 17 ENABLE (1-12)
9 BIT 4 16 START CONVERT
10 BIT 3 15 EOC
11 BIT 2 14 DIGITAL GROUND
12 BIT 1 (MSB) 13 +5V SUPPLY
REF
REGI
STER
REGI
STER
3-STATE OUTPUT REGI
STER
12 BIT 1 (MSB)
11 BIT 2
10 BIT 3
9 BIT 4
8 BIT 5
7 BIT 6
6 BIT 7
5 BIT 8
4 BIT 9
3 BIT 10
2 BIT 11
1 BIT 12 (LSB)
TIMING AND
CONTROL LOGIC
BIPOLAR 20
+10V REF. 21
START CONVERT 16
EOC 15
DI
GI
TAL CORRECTI
O
N LOGI
C
DAC
FLASH
ADC
COMP BIN 18
BUFFER
–
+
S/H
ANALOG INPUT 19
17 ENABLE (1-12)
S2
S1
13
+5V SUPPLY
22
+15V SUPPLY
23
ANALOG GROUND
14
DIGITAL GROUND
24
–15V SUPPLY