Si85xx
Si85
X X
Features
Single-chip ac current
sensor/conditioner
Low loss: Less than 1.3 mΩ
primary series resistance;
less than 2 nH primary
inductance at 25 ºC
Leading-edge noise suppression
eliminates need for leading-edge
blanking
"Ping-Pong" output version
allows one Si85xx to replace two
current transformers in full-bridge
applications
5, 10, and 20 A full-scale versions
FAULT output helps safeguard
operation
1,000 VDC isolation
Accurate to ±5% of measurement
Large 2 V
PP
output pins signal at
full scale
High-side or low-side current
sensing
–40 to 125 ºC operating range
(Si85x4/5/6)
Small 4 x 4 x 1 mm package
Low cost
Pin Assignments:
See page 20
UNIDIRECTIONAL
AC
CURRENT SENSORS
12-Pin QFN
VDD2
R1
R2
GND2
GND3
OUT
NC
IOUT
1
VDD1
IIN
Si850x
TRST
Applications
Power supplies
Motor controls
Lighting equipment
Industrial equipment
R1
R2
1
MODE
Description
The Si85xx products are unidirectional ac current sensors available in full-
scale ranges of 5, 10, and 20 A. Si85xx products are ideal upgrades for
older current-sensing technologies offering size, performance and cost
advantages over current transformers, Hall effect devices, DCR circuits
and other approaches. The Si85xx are extremely low loss, adding less
than 1.3 mΩ of series resistance and less than 2 nH series inductance in
the sensing path at 25 ºC. Current-sensing terminals are isolated from the
other package pins to a maximum voltage of 1,000 VDC.
VDD
GND1
IIN
R3
R4
OUT1
OUT2
Si851x
IOUT
Functional Block Diagram
Patents pending
IIN
R1
R2
R3
R4
Si851x
RESET LOGIC
MODE LOGIC
MODE
R2
VDD
VIN
VDD1
TRST
IIN
GND1
Si850x
IOUT
OUT
GND2
OUT1
METAL SLUG
INTEGRATOR
SIGNAL CONDITIONING
OUT2
R1
PH1
Q1
L
C
PH2
Q2
VOUT
TEMP
SENSOR
ADC
AUTO CALIBRATION
LOGIC
Typical Application
IOUT
GND
VDD
TRST/FAULT
Preliminary Rev. 0.1 7/07
Copyright © 2007 by Silicon Laboratories
TRST/FAULT
GND
Si85xx
This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Silicon Laboratories Confidential. Information contained herein is covered under non-disclosure agreement (NDA).
SILABS [ SILICON LABORATORIES ]
