ADS-238Q Datasheet, PDF (1/7 Pages) List of Unclassifed Manufacturers – 12-Bit, 20MHz, Low Power Sampling A/D Converters

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INNOVATION and EXCELLENCE
ADS-238Q
12-Bit, 20MHz, Low Power
Sampling A/D Converters
FEATURES
· 20MHz sampling rate
· Low Power, 100mW, max
· 100MHz full power input bandwidth
· Integral sample-and-hold
· Single +3V supply operation
· TTL compatible digital output
· Offset binary output coding
GENERAL DESCRIPTION
The ADS-238Q is a monolithic, 12-bit, 20MHz, sampling
analog-to-digital converter fabricated in a CMOS process.
The converter is designed for applications where high speed,
wide bandwidth and low power dissipation are essential.
These characteristics are provided through the use of a fully
differential pipeline A/D architecture with digital error
correction logic for the eleven most significant bits.
The ADS-238Q offers excellent dynamic performance while
consuming only 79mW, typical. The power dissipation is
approximately proportional to the sampling rate, thus the
ADS-238Q is ideal for low power applications between 1 and
20 MHz. With low distortion and high dynamic range, this
device provides the performance required for imaging,
telecommunications, multimedia, and instrumentation
applications.
The ADS-238Q is available in a 44-pin (plastic) TQFP
package and operates over the commercial 0°C to 70°C
temperature range.
INPUT/OUTPUT CONNECTIONS
PIN FUNCTION
PIN FUNCTION
1 GND
2 CLK
3 N.C.
4
VS
5
VS
6
VS
7
VS
8
VS
9
VS
10
VREF–
11
VREF+
12 N.C.
13 N.C.
14 N.C.
15 GND
16 BIAS1
17 BIAS2
18
VCM
19 GND
20
VIN+
21
VIN–
22 GND
44 VS
43 BIT 12 (LSB)
42 BIT 11
41 BIT 10
40 BIT 9
39 BIT 8
38 BIT 7
37 BIT 6
36 BIT 5
35 BIT 4
34 BIT 3
33 BIT 2
32 BIT 1
31 GND
30 GND
29 GND
28 GND
27 GND
26 GND
25 GND
24 GND
23 GND
Note: Recommend that N.C. (no connect) pins be connected to analog ground.
BIAS1 16
BIAS2 17
VREF+ 11
VREF– 10
VIN+ 20
VIN– 21
VCM 18
Bias
Current
Adjust
X2
å–
+
X2
Reference
Input
å–
+
S/H
Common Mode
Voltage Reference
2-Bit
Flash A/D
Stage 10
2-Bit
Flash A/D
2-Bit
DAC
Stage 1
2-Bit
Flash A/D
2-Bit
DAC
4 to 9, 44
+VS
1, 15, 19, 22 to 31
GND
Figure 1. ADS-238Q Functional Block Diagram
Digital Delay
and Error
Correction
Clock
32 Bit 1 (MSB)
33 Bit 2
34 Bit 3
35 Bit 4
36 Bit 5
37 Bit 6
38 Bit 7
39 Bit 8
40 Bit 9
41 Bit 10
42 Bit 11
43 Bit 12 (LSB)
2 CLK
DATEL, Inc., 11 Cabot Boulevard, Mansfield, MA 02048 (U.S.A.) · Tel: [phone] Fax: [phone] · For immediate assistance: [phone]