May 1997
ML2281, ML2282*,
ML2284#, ML2288#
Serial I/O 8-Bit A/D Converters with
Multiplexer Options
GENERAL DESCRIPTION
FEATURES
■ Conversion time: 6µs
The ML2281 family are 8-bit successive approximation
A/D converters with serial I/O and configurable input
multiplexers with up to 8 input channels.
■ Total unadjusted error: ±1/2LSB or ±1LSB
■ Sample-and-hold: 375ns acquisition
■ 2, 4 or 8-input multiplexer options
All errors of the sample-and-hold, incorporated on the
ML2281 family are accounted for in the analog-to-digital
converters accuracy specification.
■ 0 to 5V analog input range with single 5V
power supply
■ Operates ratiometrically or with up to 5V
The voltage reference can be externally set to any value
voltage reference
between GND and V , thus allowing a full conversion
CC
over a relatively small voltage span if desired.
■ No zero or full-scale adjust required
■ ML2281 capable of digitizing a 5V, 40kHz sine wave
■ Low power: 12.5mW MAX
The ML2281 family is an enhanced double polysilicon
CMOS pin compatible second source for the ADC0831,
ADC0832, ADC0834, and ADC0838 A/D converters. The
ML2281 series enhancements are faster conversion time,
true sample-and-hold function, superior power supply
rejection, improved AC common mode rejection, faster
digital timing, and lower power dissipation. All parameters
are guaranteed over temperature with a power supply
voltage of 5V ±10%.
■ Superior pin compatible replacement for ADC0831,
ADC0832, ADC0834, and ADC0838
■ Analog input protection: 25mA (min) per input
■ Now in 8-Pin SOIC Package (ML2281, ML2282)
(* Indicates Part is Obsolete)
(# Indicates Part is End Of Life as Of July 1, 2000)
ML2284 (8-Channel SE or 4-Channel Diff Multiplexer)
ML2288
BLOCK DIAGRAM
ML2284 ((24--CChhaannnneell SSEE oorr 12--CChhaannnneell DDiiffff MMuullttiipplleexxeerr))
ML2281
CS
CONTROL
DI
INPUT
SHIFT-REGISTER
AND
TIMING
CLK
SARS
CONTROL
4-BIT
AND
CLK
DO
OUTPUT
SHIFT-REGISTER
TIMING
CS
A/D WITH SAMPLE & HOLD FUNCTION
DO
V
V
OUTPUT
SHIFT-REGISTER
IN+
+
SUCCESSIVE
APPROXIMATION
REGISTER
+
Σ
COMP
CH0
CH1
CH2
–
–
SE
8pF
8pF
V
REF
DGND
CH3
CH4
CH5
A/D
CONVERTER
WITH
SAMPLE & HOLD
FUNCTION
IN–
D/A
CONVERTER
CH6
CH7
SHUNT
REGULATOR
V
V
V
CC
V+
CC
GND
COMMON
AGND
REF
1