ACPL-C79B, ACPL-C79A, ACPL-C790

Precision Miniature Isolation Amplifiers

Data Sheet

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.

Description

The ACPL-C79B/C79A/C790 isolation amplifiers are

designed for current and voltage sensing in electronic

power converters in applications including motor drives

and renewable energy systems. In a typical motor drive

implementation, current flows through an external

resistor and the resulting analog voltage drop is sensed by

the isolation amplifier. A differential output voltage that is

proportional to the current is created on the other side of

the optical isolation barrier.

For general applications, the ACPL-C79A (±1% gain

tolerance) and the ACPL-C790 (±3% gain tolerance)

are recommended. For high precision applications, the

ACPL-C79B (±0.5% gain tolerance) can be used. The

product operates from a single 5 V supply and provides

excellent linearity and dynamic performance of 60 dB SNR.

With 200 kHz bandwidth, 1.6

µs fast response time, the

product captures transients in short circuit and overload

conditions. The high common-mode transient immunity

(15 kV/

µs) of the ACPL-C79B/C79A/C790 provides the

precision and stability needed to accurately monitor

motor current in high noise motor control environments,

providing for smoother control (less “torque ripple”) in

various types of motor control applications.

Combined with superior optical coupling technology, the

ACPL-C79B/C79A/C790 implements sigma-delta (

∑-∆)

analog-to-digital converter, chopper stabilized ampli-

fiers, and a fully differential circuit topology to provide

unequaled isolation-mode noise rejection, low offset,

high gain accuracy and stability. This performance is

delivered in a compact, auto-insertable Stretched SO-8

(SSO-8) package that meets worldwide regulatory safety

standards.

Functional Diagram

Features

• ±0.5% High Gain Accuracy (ACPL-C79B)

• –50 ppm/°C Low Gain Drift

• 0.6 mV Input Offset Voltage

• 0.05% Excellent Linearity

• 60 dB SNR

• 200 kHz Wide Bandwidth

• 3 V to 5.5 V Wide Supply Range for Output Side

• –40°C to +105°C Operating Temperature Range

• Advanced Sigma-Delta (∑-∆) A/D Converter Technology

• Fully Differential Isolation Amplifier

• 15 kV/µs Common-Mode Transient Immunity

• Compact, Auto-Insertable Stretched SO-8 Package

• Safety and Regulatory Approvals:

– IEC/EN/DIN EN 60747-5-5: 1414 Vpeak working

insulation voltage

– UL 1577: 5000 Vrms/1min double protection rating

– CSA: Component Acceptance Notice #5

Applications

• Current/Voltage Sensing in AC and Servo Motor Drives

• Solar Inverters, Wind Turbine Inverters

• Industrial Process Control

• Data acquisition systems

• Switching Power Supply Signal Isolation

• General Purpose Analog Signal Isolation

• Traditional Current Transducer Replacements

NOTE:

A 0.1

µF bypass capacitor must be connected

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

Figure 1.

1

2

3

4

8

7

6

5

GND1

GND2

+

-

+

-

SHIELD