May 1997
ML2252*, ML2259**
µP Compatible 8-Bit A/D Converters
with 2- or 8-Channel Multiplexer
GENERAL DESCRIPTION
The ML2252 and ML2259 combine an 8-bit A/D
converter, 2- or 8-channel analog multiplexer, and a
microprocessor compatible 8-bit parallel interface and
control logic in a single monolithic CMOS device.
Easy interface to microprocessors is provided by the
latched and decoded multiplexer address inputs and a
double buffered three-state data bus. These analog-to-
digital converters allow the microprocessor to operate
completely asynchronous to the converter clock.
The built in sample and hold function provides the ability
to digitize a 5V, 50kHz sinewave to 8-bit accuracy. The
differential comparator design provides low power supply
sensitivity to DC and AC variations. The voltage reference
can be externally set to any value between ground and
V
CC
, thus allowing a full conversion over a relatively
small span. All parameters are guaranteed over
temperature with a power supply voltage of 5V ±10%.
The device is suitable for a wide range of applications
from process and machine control to consumer,
automotive, and telecommunication applications.
FEATURES
s
s
s
s
s
s
s
s
s
s
s
s
s
Conversion time (f
CLK
= 1.46MHz); 6.6µs
Total unadjusted error; ±1/2LSB or ±1LSB
No missing codes
Sample and hold; 390ns acquisition
Capable of digitizing a 5V, 50kHz sinewave
2- or 8-channel input multiplexer
0V to 5V analog input range with single 5V
power supply
Operates ratiometrically or with up to 5V
voltage reference
No zero or full scale adjust required
Analog input protection; 25mA per input min
Continuous conversion mode
Low power dissipation; 15mW max
TTL and CMOS compatible digital inputs and outputs
ML2252 BLOCK DIAGRAM
* This Part Is Obsolete
** This Part Is End of Life As Of August 1, 2000
V
CC
CH0
2-CHANNEL
MULTIPLEXER
CLOCK
CONTROL
& TIMING
START
EOC
CH1
+
Σ
–
8pF
+
COMP
–
DB0
SUCCESSIVE
APPROXIMATION
REGISTER
THREE
STATE
OUTPUT
BUFFER
D/A
CONVERTER
DB1
DB2
DB3
DB4
DB5
DB6
DB7
ADDRESS
LATCH
AND
DECODER
ALE
A0
8pF
A/D WITH
SAMPLE-AND-HOLD FUNCTION
GND
+V
REF
–V
REF
OE
1
MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
