zxct1080 Zetex Semiconductors plc., zxct1080 Datasheet - Page 8

• Manufacturer Part Number: zxct1080
• Description: Zxct1080 - 60v Common-mode Input Range Current Monitor
• Manufacturer: Zetex Semiconductors plc.

Application information
The ZXCT1080 has been designed to allow it to operate with 5V supply rails while sensing
common mode signals up to 60V. This makes it well suited to a wide range of industrial and power
supply monitoring applications that require the interface to 5V systems while sensing much
higher voltages.
To allow this its V
Figure 1 shows the basic configuration of the ZXCT1080.
Load current from the input is drawn through R
inputs of the ZXCT1080.
The internal amplifier forces V
through MOSFET M1. This current is then converted to a voltage by R
R
The gain equation of the ZXCT1080 is:
The maximum recommended differential input voltage, V
withstand voltages up to 800m . This can be increased further by the inclusion of a resistor, R
between S- pin and the load; typical value is of the order of 10k .
Issue 3 - March 2008
© Zetex Semiconductors plc 2008
G
and R
V
OUT
GT
creates the fixed gain of 10. The output is then buffered by the unity gain buffer.
=
I
L
R
CC
SENSE
pin can be used independently of S+.
GND
OUT
Input
V
--------- - 1
R
R
CC
Figure 1 Typical configuration of ZXCT1080
GT
G
×
ZXCT1080
=
SENSE
S +
I
L
A2+1
×
R
across internal resistance R
SENSE
M1
R
R
GT
×
G
10
R
8
SENSE
SENSE
A1
developing a voltage V
S -
SENSE
GT
, is 150mV; it will however
Load
causing a current to flow
G
. A ratio of 10:1 between
ZXCT1080
SENSE
www.zetex.com
across the
LIM
,