AD22001_15 Datasheet, PDF (1/8 Pages) Analog Devices – 5-Channel Monolithic Comparator for Lamp Monitoring

a
5-Channel Monolithic Comparator
for Lamp Monitoring
FEATURES
Continuous Status Checks of Five Bulbs
Lamp Status Check in “ON” and “OFF” States
Status Checks of Two In-Line Fuses
Very Low Voltage Drop at Sensor Shunt Resistor
(Comparator Threshold 1.75 mV at 22؇C)
Temperature and Supply Voltage Compensated
Powered Directly from Car Battery: Protection
Included for Transient, Reverse Supply, Load Dump
Operating Temperature Range: –40؇C to +125؇C
15 V CMOS Compatible Digital Output Signals
Voltage Limited Power Supply Output for 15 V CMOS
Logic ICs
GENERAL DESCRIPTION
The AD22001 is a monolithic, five-channel comparator circuit
for monitoring the functionality of lamps in automotive
applications.
The IC tests the series circuit leading to the lamp to determine
if the circuit is intact and a functional lamp is in the socket. The
AD22001 continuously checks the functionality of up to five
bulbs in either their “on” or “off” state, and also tests for the
presence of an in-line fuse in two of the series circuits.
Digital outputs indicate the status of each channel. Additionally,
the AD22001 provides a voltage limited power supply output to
supply 15 V CMOS circuits that may interface to the AD22001.
AD22001*
FUNCTIONAL BLOCK DIAGRAM
+V_S 2
CHIP ₁
ENABLE
GND 20
–IN1 4
+IN1 5
IN_FUSE1 & 2 6
–IN2 9
+IN2 ⁸
–IN3 ¹¹
+IN3 ¹⁰
–IN4 ¹⁴
+IN4 ¹⁵
–IN5 ¹⁶
+IN5 ¹⁷
IN_FUSE5 19
3
SWITCH &
LIMITER
AD22001
CHANNEL 1
POWER
OUT
7
OUT 1 & 2
CHANNEL 2
CHANNEL 3
13
12
OUT 3 & 4
OUT (3 × 4)
CHANNEL 4
CHANNEL 5
18
OUT 5
+V BATT
FUSE
SWITCH
COPPER
SHUNT
RESISTOR
OUTPUT
LAMP
SIGNAL CONDITIONING
AND SIGNAL PROCESSING
Figure 1. Typical Application Circuit for a Single Channel Lamp Monitor
REV. A
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