TL/H/10554
ADC1241
Self-Calibrating
12-Bit
Plus
Sign
m
P-Compatible
A/D
Converter
with
Sample-and-Hold
November 1994
ADC1241 Self-Calibrating 12-Bit Plus
Sign mP-Compatible A/D Converter
with Sample-and-Hold
General Description
The ADC1241 is a CMOS 12-bit plus sign successive ap-
proximation analog-to-digital converter. On request, the
ADC1241 goes through a self-calibration cycle that adjusts
positive linearity and full-scale errors to less than g(/2 LSB
each and zero error to less than g1 LSB. The ADC1241
also has the ability to go through an Auto-Zero cycle that
corrects the zero error during every conversion.
The analog input to the ADC1241 is tracked and held by the
internal circuitry, and therefore does not require an external
sample-and-hold. A unipolar analog input voltage range (0V
to a5V) or a bipolar range (b5V to a5V) can be accom-
modated with g5V supplies.
The 13-bit word on the outputs of the ADC1241 gives a 2’s
complement representation of negative numbers. The digi-
tal inputs and outputs are compatible with TTL or CMOS
logic levels.
Applications
Y
Digital Signal Processing
Y
High Resolution Process Control
Y
Instrumentation
Key Specifications
Y
Resolution 12 Bits plus Sign
Y
Conversion Time 13.8ms (max)
Y
Linearity Error g(/2 LSB (g0.0122%) (max)
Y
Zero Error g1LSB (max)
Y
Positive Full Scale Error g1LSB (max)
Y
Power Consumption 70mW (max)
Features
Y
Self-calibrating
Y
Internal sample-and-hold
Y
Bipolar input range with g5V supplies and single
a5V reference
Y
No missing codes over temperature
Y
TTL/MOS input/output compatible
Y
Standard 28-pin DIP
TRI-STATE is a registered trademark of National Semiconductor Corporation.
Simplified Schematic
TL/H/10554–1
Connection Diagram
Dual-In-Line Package
TL/H/10554–2
Top View
Order Number ADC1241CMJ,
ADC1241CMJ/883, ADC1241BIJ or
ADC1241CIJ
See NS Package Number J28A
C
1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.