ADS944 Datasheet, PDF (1/8 Pages) List of Unclassifed Manufacturers – 14-Bit, 5MHz Sampling A/D Converters

®
®
FEATURES
• 14-bit resolution
• 5MHz minimum sampling rate
• No missing codes over full military temperature range
• Edge-triggered, no pipeline delay
• Low power, 2.95 Watts
• Small, 32-pin, ceramic TDIP package
• SMT package available
• Excellent dynamic performance
• MIL-STD-883 screening or DESC SMD available
GENERAL DESCRIPTION
The low-cost ADS-944 is a high-performance, 14-bit, 5MHz
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-944 has been
optimized to achieve a THD of –77dB and a SNR of 76dB.
Packaged in a small, 32-pin TDIP, the functionally complete
ADS-944 contains a fast-settling sample-hold amplifier, a
subranging (two-pass) A/D converter, an internal reference,
timing and control logic, three-state outputs, and error-
correction circuitry. Digital input and output levels are TTL.
Requiring ±15V, +5V and –5.2V supplies, the ADS-944
typically dissipates 2.95 Watts. The unit is offered with a
bipolar input range of ±1.25V. Models are available for use in
either commercial (0 to +70°C) or military (–55 to +125°C)
operating temperature ranges. Typical applications include
radar signal analysis, medical/graphic imaging, and
FFT spectrum analysis.
ADS-944
14-Bit, 5MHz
Sampling A/D Converters
INPUT/OUTPUT CONNECTIONS
PIN FUNCTION
PIN FUNCTION
1
+5V ANALOG SUPPLY 32 START CONVERT
2
–5.2V DIGITAL SUPPLY 31 BIT 1 (MSB)
3
ANALOG INPUT
30 BIT 1 (MSB)
4
ANALOG GROUND
29 BIT 2
5
OFFSET ADJUST
28 BIT 3
6
ANALOG GROUND
27 BIT 4
7
GAIN ADJUST
26 BIT 5
8
COMP. BITS
25 BIT 6
9
OUTPUT ENABLE
24 BIT 7
10 +5V DIGITAL SUPPLY 23 BIT 8
11 ANALOG GROUND
22 BIT 9
12 +15V SUPPLY
21 BIT 10
13 –15V SUPPLY
20 BIT 11
14 –5.2V ANALOG SUPPLY 19 BIT 12
15 DIGITAL GROUND
18 BIT 13
16 EOC
17 BIT 14 (LSB)
ANALOG INPUT 3
GAIN ADJUST 7
OFFSET ADJUST 5
START CONVERT 32
EOC 16
–
S/H
+
GAIN
CIRCUIT
BUFFER
FLASH
ADC
1
REF
DAC
Σ
OFFSET
CIRCUIT
AMP
FLASH
ADC
2
TIMING AND
CONTROL LOGIC
31 BIT 1 (MSB)
30 BIT 1 (MSB)
29 BIT 2
28 BIT 3
27 BIT 4
26 BIT 5
25 BIT 6
24 BIT 7
23 BIT 8
22 BIT 9
21 BIT 10
20 BIT 11
19 BIT 12
18 BIT 13
17 BIT 14 (LSB)
9 OUTPUT ENABLE
1
+5V
ANALOG
SUPPLY
2
–5.2V
DIGITAL
SUPPLY
4, 6, 11
ANALOG
GROUND
10
+5V
DIGITAL
SUPPLY
12
+15V
SUPPLY
14
–5.2V
ANALOG
SUPPLY
Figure 1. ADS-944 Functional Block Diagram
15
DIGITAL
GROUND
8
COMP.
BITS
DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.) • Tel: [phone] Fax: [phone] • For immediate assistance: [phone]