May 1997
ML2258*
µP Compatible 8-Bit A/D Converter
with 8-Channel Multiplexer
1
GENERAL DESCRIPTION
The ML2258 combines an 8-bit A/D converter, 8-channel
analog multiplexer, and a microprocessor compatible 8-
bit parallel interface and control logic in a single
monolithic device.
Easy interface to microprocessors is provided by the
latched and decoded multiplexer address inputs and
latched three-state outputs.
The device is suitable for a wide range of applications
from process and machine control to consumer,
automotive, and telecommunication applications.
The ML2258 is an enhanced, pin-compatible, second
source for the industry standard ADC0808/ADC0809. The
ML2258 enhancements are faster conversion time, true
sample and hold function, superior power supply
rejection, wider reference range, and a double buffered
data bus as well as faster digital timing. All parameters
are guaranteed over temperature with a power supply
voltage of 5V ±10%.
FEATURES
a73 Conversion time 6.6µs
a73 Total unadjusted error ±1/2LSB or ±1LSB
a73 No missing codes
a73 Sample and hold 390ns acquisition
a73 Capable of digitizing a 5V, 50kHz sine wave
a73 8-input multiplexer
a73 0V to 5V analog input range with single 5V
power supply
a73 Operates ratiometrically or with up to 5V
voltage reference
a73 No zero-or full-scale adjust required
a73 Analog input protection 25mA per input min
a73 Low power dissipation 3mA max
a73 TTL and CMOS compatible digital inputs and outputs
a73 Standard 28-pin DIP or surface mount PCC
a73 Superior pin compatible replacement for ADC0808 and
ADC0809
* Some Packages Are End Of Life As Of August 1, 2000
BLOCK DIAGRAM
COMPARATOR
A/D WITH
SAMPLE HOLD
CONTROL & TIMING
S.A.R.
SWITCH TREE
THREE
STATE
OUTPUT
LATCH
BUFFER
DB0
DB1
DB2
DB3
DB4
DB5
DB6
DB7
OUTPUT
ENABLE
–V
REF
+V
REF
GNDV
CC
CAPACITOR/
RESISTOR
ARRAY
ADDRESS
LATCH
AND
DECODER
ADDR0
ADDR1
ADDR2
ADDRESS
LATCH ENABLE
IN7
IN6
IN0
IN1
IN2
IN3
IN4
IN5
8-CHANNEL
MULTIPLEXER
START CLOCK
END OF CONVERSION
(INTERRUPT)