®
®
ADS-946
14-Bit, 8MHz
Sampling A/D Converters
INNOVATION and EXCELLENCE
FEATURES
•
•
•
•
•
•
•
•
•
•
14-bit resolution
8MHz guaranteed sampling rate
No missing codes over full military temperature range
Ideal for both time and frequency-domain applications
Excellent THD (–75dB) and SNR (77dB)
Edge-triggered; No pipeline delays
Small, 24-pin, ceramic DDIP or SMT
Requires only ±5V supplies
Low-power, 2 Watts
MIL-STD-883 screening optional
GENERAL DESCRIPTION
The low-cost ADS-946 is a 14-bit, 8MHz sampling A/D
converter. This device accurately samples full-scale input
signals up to Nyquist frequencies with no missing codes.
Excellent differential nonlinearity error (DNL), signal-to-noise
ratio (SNR), and total harmonic distortion (THD) make the
ADS-946 the ideal choice for both time-domain (CCD/FPA
imaging, scanners, process control) and frequency-domain
(radar, telecommunications, spectrum analysis) applications.
The functionally complete ADS-946 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. The
ADS-946 only requires the rising edge of a start convert
pulse to operate.
Requiring only ±5V supplies, the ADS-946 typically dissipates
just 2 Watts. The device is offered with a bipolar input range
of ±2V. Models are available for use in either commercial
(0 to +70°C) or military (–55 to +125°C) operating
PIN
1
2
3
4
5
6
7
8
9
10
11
12
INPUT/OUTPUT CONNECTIONS
FUNCTION
BIT
BIT
BIT
BIT
BIT
BIT
BIT
BIT
BIT
BIT
BIT
BIT
1 (MSB)
2
3
4
5
6
7
8
9
10
11
12
PIN
24
23
22
21
20
19
18
17
16
15
14
13
FUNCTION
ANALOG GROUND
OFFSET ADJUST
+5V ANALOG SUPPLY
ANALOG INPUT
–5V SUPPLY
ANALOG GROUND
START CONVERT
EOC
BIT 14 (LSB)
BIT 13
DIGITAL GROUND
+5V DIGITAL SUPPLY
temperature ranges. A proprietary, auto-calibrating, error-
correcting circuit allows the device to achieve specified
performance over the full military temperature range.
OFFSET ADJUST 23
BUFFER
REGISTER
ANALOG INPUT 21
–
S/H
+
FLASH
ADC
1
16 BIT 14 (LSB)
15 BIT 13
12 BIT 12
DIGITAL CORRECTION LOGIC
11 BIT 11
OUTPUT REGISTER
10 BIT 10
9
8
7
6
5
4
3
2
1
BIT 9
BIT 8
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1 (MSB)
POWER AND GROUNDING
REF
+5V ANALOG SUPPLY
+5V DIGITAL SUPPLY
–5V SUPPLY
ANALOG GROUND
DIGITAL GROUND
22
13
20
19, 24
14
AMP
FLASH
ADC
2
REGISTER
DAC
Σ
START CONVERT 18
EOC 17
TIMING AND
CONTROL LOGIC
Figure 1. ADS-946 Functional Block Diagram
DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048 (U.S.A.)
•
Tel: (508)339-3000 Fax: (508)339-6356
•
For immediate assistance: (800) 233-2765
MURATA-PS [ MURATA POWER SOLUTIONS INC. ]
