®
®
ADS-943
14-Bit, 3MHz, Low-Distortion
Sampling A/D Converters
FEATURES
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14-bit resolution
3MHz minimum sampling rate
Ideal for both frequency and time-domain applications
Excellent peak harmonics, –83dB
Excellent signal-to-noise ratio, 79dB
No missing codes over full military temperature range
±5V supplies, 1.7 Watts
Small, 24-pin ceramic DDIP or SMT
Low cost
PIN
1
2
3
4
5
6
7
8
9
10
11
12
INPUT/OUTPUT CONNECTIONS
FUNCTION
BIT1 (MSB)
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
BIT 8
BIT 9
BIT 10
BIT 11
BIT 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
GENERAL DESCRIPTION
The low-cost ADS-943 is a 14-bit, 3MHz sampling A/D
converter optimized to meet the demanding dynamic-range
and sampling-rate requirements of contemporary digital
telecommunications applications. The ADS-943's outstanding
dynamic performance is evidenced by a peak harmonic
specification of –83dB and a signal-to-noise ratio (SNR) of
79dB. Additionally, the ADS-943 easily achieves the 2.2MHz
minimum sampling rate required by digital receivers in certain
ADSL, HDSL and ATM applications. The ADS-943 also
addresses size and power constraints normally associated with
these types of applications. This device requires just ±5V
supplies, dissipates 1.7 Watts, and is packaged in a very small
24-pin DDIP.
Although optimized for frequency-domain applications, the
ADS-943's DNL and noise specifications are also outstanding,
thereby making it an equally impressive device for time-domain
applications (graphic and medical imaging, process control,
etc.). In fact, the ADS-943 guarantees no missing codes to the
14-bit level over the full military operating temperature range.
The functionally complete ADS-943 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 unit is
edge-triggered, requiring only the rising edge of a start convert
pulse to initiate a conversion.
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 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
DIGITAL GROUND
–5V SUPPLY
ANALOG GROUND
22
13
14
20
19, 24
AMP
FLASH
ADC
2
REGISTER
DAC
Σ
START CONVERT 18
EOC 17
TIMING AND
CONTROL LOGIC
Figure 1. ADS-943 Functional Block Diagram
DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048-1151 (U.S.A.)
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Tel: (508) 339-3000 Fax: (508) 339-6356
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For immediate assistance: (800) 233-2765
MURATA-PS [ MURATA POWER SOLUTIONS INC. ]
