Avago Technologies ACPL-C790-000E User Manual
User guide, Isolated current sensing module with acpl-c79x

Isolated Current Sensing Module with ACPL-C79X
User Guide
Introduction
The ACPL-C79x isolated current sense evaluation module,
shown in Figure 1, is pin-to-pin compatible with several
Hall effect current transducers. The evaluation module has
a ±1% (ACPL-C79A) isolation amplifier gain accuracy, but
the ACPL-C79x is also offered with a ±0.5% (ACPL-C79B)
or ±3% (ACPL-C790) specification. The ACPL-C79B/C79A/
C790 isolation amplifiers were designed for current and
voltage sensing in electronic power converter, motor
drive and renewable energy applications.
For many compact power drive designs, a shunt resistor
plus isolation amplifier measurement solution has many
benefits over traditional Hall effect current sensors. The
benefits include a smaller, lower profile component with
better linearity, lower temperature drift, and lower cost.
As shown in Figure 2, the evaluation module is 20 mm by
16 mm and 24 mm high.
Key components, including the shunt resistor and isola-
tion amplifier, are available in small surface mount pack-
ages. Some designers who are familiar with current trans-
ducers can find using the shunt resistor plus optically
isolated isolation amplifier a challenge. This evaluation
module makes the evaluation quick and very easy.
The evaluation module is pin-to-pin compatible with se-
lected Hall effect current transducers, such as LEM’s LTS
6-NP, LTS 15-NP, LTS 25-NP, CAS 6-NP, CAS 15-NP, and CAS
25-NP models
[1]
. With the evaluation module, designers
using the LTS and CAS devices will find it easy to evaluate
and compare the ACPL-C79X based current sensing solu-
tion against their existing Hall effect current transducer
solutions. For example, a designer can simply remove an
LTS 15-NP device and plug in the evaluation module and
start a quick evaluation.
Figure 1. ACPL-C79x isolated current sense evaluation module
Figure 2. Current sense isolation amplifier evaluation module
ACPL-C79A
DC-DC converter
Shunt Resistor
PCB1
PCB2
Note 1. Products of LEM Holding SA