Description
The HCPL-0370/3700 and HCPL-3760 are voltage/cur-
rent threshold detection optocouplers. The HCPL-3760 is
a low-current version of the HCPL-0370/3700. To obtain
lower current operation, the HCPL-3760 uses a high-effi-
ciency AlGaAs LED which provides higher light output at
lower drive currents. The devices utilize threshold sens-
ing input buffer ICs which permit control of threshold
levels over a wide range of input voltages with a single
external resistor.
The input buffer incorporates several features: hysteresis
for extra noise immunity and switching immunity, a di-
ode bridge for easy use with ac input signals, and inter-
nal clamping diodes to protect the buffer and LED from
a wide range of over-voltage and over-current transients.
Because threshold sensing is done prior to driving the
LED, variations in optical coupling from the LED to the
detector will have no effect on the threshold levels.
Functional Diagram
HCPL-0370, HCPL-3700, HCPL-3760
Isolated Voltage/Current Detectors
Data Sheet
Features
• Standard (HCPL-0370/3700) and low input current
(HCPL-3760) versions
• AC or DC input
• Programmable sense voltage
• Hysteresis
• Logic compatible output
• Thresholds guaranteed over temperature
• Thresholds independent of LED optical parameters
• Recognized under UL 1577 and CSA approved for
dielectric withstand proof test voltage of 3750 Vac, 1
minute
Applications
• Limit switch sensing
• Low voltage detector
• AC mains and DC link voltage detection
• Relay contact monitor
• Relay coil voltage monitor
• Current sensing
• Microprocessor interfacing
Lead (Pb) Free
RoHS 6 fully
compliant
RoHS 6 fully compliant options available;
-xxxE denotes a lead-free product
CAUTION: It is advised that normal static precautions be taken in handling and assembly
of this component to prevent damage and/or degradation which may be induced by ESD.
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HCPL-3700 Functional Diagram
AC
DC+
DC-
AC
V
CC
V
O
GND
TRUTH TABLE
(POSITIVE LOGIC)
INPUT
H
L
OUTPUT
L
H
NC
