ADC0852 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – Multiplexed Comparator with 8-Bit Reference Divider

April 1995
ADC0852 ADC0854
Multiplexed Comparator with 8-Bit Reference Divider
General Description
The ADC0852 and ADC0854 are CMOS devices that com-
bine a versatile analog input multiplexer voltage compara-
tor and an 8-bit DAC which provides the comparator’s
threshold voltage (V_TH) The comparator provides a ‘‘1-bit’’
output as a result of a comparison between the analog input
and the DAC’s output This allows for easy implementation
of set-point on-off or ‘‘bang-bang’’ control systems with
several advantages over previous devices
The ADC0854 has a 4 input multiplexer that can be software
configured for single ended pseudo-differential and full-dif-
ferential modes of operation In addition the DAC’s refer-
ence input is brought out to allow for reduction of the span
The ADC0852 has a two input multiplexer that can be con-
figured as 2 single-ended or 1 differential input pair The
DAC reference input is internally tied to V_CC
The multiplexer and 8-bit DAC are programmed via a serial
data input word Once programmed the output is updated
once each clock cycle up to a maximum clock rate of
400 kHz
Features
Y _{2 or 4 channel multiplexer}
Y _{Differential or Single-ended input software controlled}
Y _{Serial digital data interface}
Y _{256 programmable reference voltage levels}
Y _{Continuous comparison after programming}
Y _{Fixed ratiometric or reduced span reference capability}
(ADC 0854)
Key Specifications
Y _Accuracy g _{LSB or} g _{1 LSB of Reference (0 2%)}
Y _{Single 5V power supply}
Y _{Low Power 15 mW}
TL H 5521 – 1
FIGURE 1 ADC0854 Simplified Block Diagram (ADC0852 has 2 input channels
COM tied to GND V_REF tied to V_CC Va omitted and one GND connection)
2 Channel and 4 Channel Pin Out
ADC0852 2-CHANNEL MUX
Dual-In-Line Package
ADC0854 4-CHANNEL MUX
Dual-In-Line Package
Top View
TL H 5521 – 10
AGND and COM internally connected to GND
V_REF internally connected to V_CC
Order Number ADC0852
See NS Package Number N08E
TRI-STATE is a registered trademark of National Semiconductor Corporation
C1995 National Semiconductor Corporation TL H 5521
Top View
TL H 5521 – 11
Order Number ADC0854
See NS Package Number N14A
RRD-B30M75 Printed in U S A