HCPL-7800A/HCPL-7800

Isolation Amplifer

Datasheet

Description

The HCPL-7800(A) isolation amplifier family was designed

for current sensing in electronic motor drives. In a typical

implementation, motor currents flow through an external

resistor and the resulting analog voltage drop is sensed

by the HCPL-7800(A). A differential output voltage is

created on the other side of the HCPL-7800(A) optical

isolation barrier. This differential output voltage is pro-

portional to the motor current and can be converted to

a single-ended signal by using an op-amp as shown in

the recommended application circuit. Since common-

mode voltage swings of several hundred volts in tens of

nanoseconds are common in modern switching inverter

motor drives, the HCPL-7800(A) was designed to ignore

very high common-mode transient slew rates (of at least

10 kV/µs).

The high CMR capability of the HCPL-7800(A) isolation

amplifier provides the precision and stability needed to

accurately monitor motor current in high noise motor

control environ-ments, providing for smoother control

(less “torque ripple”) in various types of motor control

applications.

The product can also be used for general analog signal

isolation applications requiring high accuracy, stability,

and linearity under similarly severe noise con-ditions.

For general applications, we recommend the HCPL-7800

(gain tolerance of ±3%). For precision applications Avago

Technologies offers the HCPL-7800A with part-to-part

gain tolerance of ±1%. The HCPL-7800(A) utilizes sigma

delta (Σ−∆) analog-to-digital converter technology,

chopper stabilized amplifiers, and a fully differential

circuit topology.

Together, these features deliver unequaled isolation-

mode noise rejection, as well as excellent offset and

gain accuracy and stability over time and temperature.

This performance is delivered in a compact, auto-insert-

able, industry standard 8-pin DIP package that meets

worldwide regulatory safety standards. (A gull-wing

surface mount option #300 is also available).

Features

• Compact, Auto-Insertable Standard 8-pin DIP Pack-

age

• 0.00025 V/V/°C Gain Drift vs. Temperature

• 0.3 mV Input Offset Voltage

• 100 kHz Bandwidth

• 0.004% Nonlinearity

• WorldwideSafetyApproval:UL1577(3750Vrms/1min.)

and CSA, IEC/EN/DIN EN 60747-5-2

• Advanced Sigma-Delta (Σ−∆) A/D Converter Technol-

ogy

• Fully Differential Circuit Topology

Applications

• Motor Phase and Rail Current Sensing

• Inverter Current Sensing

• Switched Mode Power Supply Signal Isolation

• General Purpose Current Sensing and Monitoring

• General Purpose Analog Signal Isolation

Functional Diagram

1

2

3

4

8

7

6

5

GND1

GND2

+

-

+

-

SHIELD

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.

Lead (Pb) Free

RoHS 6 fully

compliant

RoHS 6 fully compliant options available;

-xxxE denotes a lead-free product

NOTE: A 0.1 μF bypass capacitor must be connected

between pins 1 and 4 and between pins 5 and 8.