Agilent HCPL-7860/HCPL-786J
Optically Isolated
Sigma-Delta (Σ−∆ Modulator
Σ−∆)
Σ−∆
Data Sheet
In operation, the HCPL-7860/
HCPL-786J Isolated Modulator
(optocoupler with 3750 V
RMS
dielectric withstand voltage
rating) converts a low-
bandwidth analog input into a
high-speed one-bit data stream
by means of a Sigma-Delta (Σ−
∆)
over-sampling modulator.
This modulation provides for
high noise margins and
excellent immunity against
isolation-mode transients. The
modulator data and on-chip
sampling clock are encoded
and transmitted across the
isolation boundary where they
are recovered and decoded
into separate high-speed clock
and data channels.
Features
•
12-bit Linearity
•
200 ns Conversion Time (Pre-
Trigger Mode 2 with HCPL-0872)
•
12-bit Effective Resolution with 5
µ
s Signal Delay (14-bit with 102
µ
s) (with HCPL-0872)
•
Fast 3
µ
s Over-Range Detection
(with HCPL-0872)
•
± 200 mV Input Range with Single
5 V Supply
•
1% Internal Reference Voltage
Matching
•
Offset Calibration (with HCPL-
0872)
•
-40°C to +85°C Operating
Temperature Range
•
15 kV/µs Isolation Transient
µ
Immunity
8
SIGMA
DELTA
MOD./
ENCODE
Description
The HCPL-7860/HCPL-786J
Optically Isolated Modulator
and HCPL-0872 Digital
Interface IC or digital filter
together form an isolated
programmable two-chip
analog-to-digital converter. The
isolated modulator allows
direct measurement of motor
phase currents in power
inverters.
1
2
Input
Current
3
4
HCPL-7860
•
Safety Approval: UL 1577, CSA
and IEC/EN/DIN EN 60747-5-2
HCPL-0872
or
Digital Filter
MCU
or
DSP
7
DECODE
6
Applications
•
Motor Phase and Rail Current
Sensing
•
Data Acquisition Systems
•
Industrial Process Control
•
Inverter Current Sensing
•
General Purpose Current Sensing
and Monitoring
5
A 0.1 µF bypass capacitor must be connected between pins V
DD
and Ground
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.
SPI and QSPI are trademarks of Motorola Corp.
Microwire is a trademark of National Semiconductor Inc.