®
®
ADS-325A
10-Bit, 20MHz
Sampling A/D Converter
IN N O VA T IO N a n d E X C E L L E N C E
FEATURES
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10-bit, 20MHz sampling
±1LSB max. differential nonlinearity
Internal calibration circuit
Internal S/H amplifier
70MHz input bandwidth
TTL/CMOS compatible in-out logic
Latched three-state output data
Single +5V supply
Low 150mW power dissipation
Small 48 pin LQFP package
Low cost
INPUT/OUTPUT CONNECTIONS
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
FUNCTION
BIT 10 (LSB)
BIT 9
BIT 8
BIT 7
BIT 6
DIGITAL GROUND (DGND)
+DV
S
(Digital)
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1 (MSB)
TEST PIN
TEST SIGNAL IN
RESET
DIGITAL GROUND (DGND)
SELECT (SEL)
+AVS (Analog)
TEST MODE
LINV
MINV
A/D CLOCK
OUTPUT ENABLE (OE)
CHIP ENABLE (CE)
PIN
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
FUNCTION
DIGITAL GROUND (DGND)
NO CONNECTION
NO CONNECTION
+DV
S
(Digital)
ANALOG GROUND (AGND)
ANALOG GROUND (AGND)
TEST SIGNAL IN
CALIBRATION (CAL)
NO CONNECTION
ANALOG INPUT (V
IN
)
TEST SIGNAL OUT
TEST SIGNAL IN
ANALOG GROUND (AGND)
REFERENCE BOTTOM (
VRB
)
REFERENCE BOTTOM (V
RB
)
NO CONNECTION
NO CONNECTION
NO CONNECTION
REFERENCE TOP (V
RT
)
REFERENCE TOP (V
RT
)
ANALOG GROUND (AGND)
ANALOG GROUND (AGND)
+AVS (Analog)
+AVS (Analog)
GENERAL DESCRIPTION
DATEL's ADS-325A is a low power, 10-bit, 20MHz, CMOS
sampling A/D converter. Its small 48 pin plastic LQFP package
contains a S/H amplifier, a 3-state output register, linearity
calibration circuitry, and all necessary control logic. Only two
external reference voltages, an A/D clock and a few digital
inputs are required. The A/D clock may be applied with 50%
duty cycle.
The excellent dynamic performance includes a spurious free
dynamic range of 65dB and a signal-to-noise ratio with
distortion of 54dB with a 3MHz input. ADS-325A is capable of
operating from a single +5V power supply and typically
consumes only 150mW. It can also operate from a +5V analog
V
S
with +3.3V digital V
S
enabling an interface with 3.3V logic
circuitry. The ADS-325A is ideally suited for high quality video/
CCD imaging applications.
AGND
+AV
S
44
43
27
28
36
18
25
26
SENSE
AMP
#1
12 BIT 1 (MSB)
COARSE
CORRECTION
AND
LATCH
11 BIT 2
10 BIT 3
9 BIT 4
8 BIT 5
V
IN
39
V
RT
29
V
RT
30
S/H AMP
+
x8
5 BIT 6
COARSE
COMPARISON
AND
ENCODE
DAC
FINE
COMPARISON
AND
ENCODE
4 BIT 7
FINE
LATCH
3 BIT 8
2 BIT 9
1 BIT 10 (LSB)
SENSE
AMP
#2
21 MINV
20 LINV
19 TEST MODE
V
RB
34
V
RB
35
CALIBRATION
UNIT
A/D CLOCK 22
CE 24
OE 23
TIMING GEN.
AUTOCALIBRATION
PULSE
GENERATOR
41 CAL
17 SEL
15 RESET
Figure 1. ADS-325A Functional Block Diagram
DATEL, Inc., Mansfield, MA 02048 (USA)
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Tel: (508) 339-3000, (800) 233-2765 Fax: (508) 339-6356
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Email: sales@datel.com
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Internet: www.datel.com
MURATA-PS [ MURATA POWER SOLUTIONS INC. ]
