TL/H/11490
ADC12062
12-Bit,
1
MHz,
75
mW
A/D
Converter
with
Input
Multiplexer
and
Sample/Hold
December 1994
ADC12062
12-Bit, 1 MHz, 75 mW A/D Converter
with Input Multiplexer and Sample/Hold
General Description
Using an innovative multistep conversion technique, the
12-bit ADC12062 CMOS analog-to-digital converter digitizes
signals at a 1 MHz sampling rate while consuming a maxi-
mum of only 75 mW on a single a5V supply. The
ADC12062 performs a 12-bit conversion in three lower-res-
olution ‘‘flash’’ conversions, yielding a fast A/D without the
cost and power dissipation associated with true flash ap-
proaches.
The analog input voltage to the ADC12062 is tracked and
held by an internal sampling circuit, allowing high frequency
input signals to be accurately digitized without the need for
an external sample-and-hold circuit. The multiplexer output
is available to the user in order to perform additional exter-
nal signal processing before the signal is digitized.
When the converter is not digitizing signals, it can be placed
in the Standby mode; typical power consumption in this
mode is 100 mW.
Features
Y
Built-in sample-and-hold
Y
Single a5V supply
Y
Single channel or 2 channel multiplexer operation
Y
Low Power Standby mode
Key Specifications
Y
Sampling rate 1 MHz (min)
Y
Conversion time 740 ns (typ)
Y
Signal-to-Noise Ratio, f
IN
e 100 kHz 69.5 dB (min)
Y
Power dissipation (f
s
e 1 MHz) 75 mW (max)
Y
No missing codes over temperature Guaranteed
Applications
Y
Digital signal processor front ends
Y
Instrumentation
Y
Disk drives
Y
Mobile telecommunications
Y
Waveform digitizers
Block Diagram
TL/H/11490–1
Ordering Information
Industrial (b40§C
s
T
A
s a
85§) Package
ADC12062BIV V44 Plastic Leaded Chip Carrier
ADC12062BIVF VGZ44A Plastic Quad Flat Package
ADC12062CIV V44 Plastic Leaded Chip Carrier
ADC12062CIVF VGZ44A Plastic Quad Flat Package
ADC12062EVAL Evaluation Board
TRI-STATE is a registered trademark of National Semiconductor Corporation.
C
1995 National Semiconductor Corporation RRD-B30M75/Printed in U. S. A.