zxct1080 Zetex Semiconductors plc., zxct1080 Datasheet - Page 9

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

Capacitor C
are of the order 10pF
For best performance R
minimizing any series resistance with R
When choosing appropriate values for R
signal loss (including potential power dissipation effects) and small signal accuracy.
Higher values for R
due to internal offsets. For best operation the ZXCT1080 has been designed to operate with
V
Current monitors' basic configuration is that of a unipolar voltage to current to voltage converter
powered from a single supply rail. The internal amplifier at the heart of the current monitor may
well have a bipolar offset voltage but the output cannot go negative; this results in current
monitors saturating at very low sense voltages.
As a result of this phenomenon the ZXCT1080 has been specified to operate in a linear manner
over a V
of 0V.
It is for this very reason that Zetex has specified an input offset voltage (V
output voltage for any V
Alternatively the load current can be expressed as:
Issue 3 - March 2008
© Zetex Semiconductors plc 2008
SENSE
V
I
L
of the order of 50mV to 150mV.
OUT
SENSE
=
(
------------------------------------------ -
D
V
=
GxR
OUT
provides high frequency transient decoupling when used with R
range of 10mV to 150mV range, however it will still be monotonic down to
(
V
SENSE
–
SENSE
V
SENSE
O 10
(
)xG
Figure 2 Protection/error sources for ZXCT1080
)
SENSE
)
SENSE
gives better accuracy at low load currents by reducing the inaccuracies
+
V
O 10
voltage from 10mV to 150mV can be calculated as follows:
(
should be connected as close to the S+ (and SENSE ) pins;
)
S +
SENSE
SENSE
ZXCT1080
R
SENSE
.
C
a compromise must be reached between in-line
9
D
S -
R
LIM
O(10)
ZXCT1080
LIM
www.zetex.com
; typical values
) at 10mV. The
VSENSE