ZXCT1022
Low offset high-side current monitor
Description
The ZXCT1022 is a precision high-side current
sense monitor. Using this type of device
eliminates the need to disrupt the ground
plane when sensing a load current.
The ZXCT1022 provides a fixed gain of 100 for
applications where minimal sense voltage is
required.
The very low offset voltage enables a typical
accuracy of 3% for sense voltages of only 10mV,
giving better tolerances for small sense
resistors necessary at higher currents.
The wide input voltage range of 20V down to as
low as 2.5V make it suitable for a range of
applications. With a minimum operating
current of just 25µA, combined with its SOT23-
5 package make it suitable for portable battery
equipment too.
Features
•
•
•
•
•
Accurate high-side current sensing
Ground referred output
2.5V – 20V supply range
25 A quiescent current
SOT23-5 package
Applications
•
•
•
•
•
•
Battery chargers
Smart battery packs
DC motor control
Over-current protection
Power supply current measurement
Level translating
Pinout information
NC
GND
V
OUT
Pinout - top view
Typical application circuit
V
SENSE
-
V
SENSE
+
Ordering information
Order reference
ZXCT1022E5TA
Package
SOT23-5
Device
marking
1022
Status
Active
Reel size
(inches)
7
Quantity
per reel
3000
Tape width
(mm)
8
Issue 6 - March 2008
© Zetex Semiconductors plc 2008
1
www.zetex.com
ZXCT1022
Absolute maximum ratings
Voltage on V
s+ (*)
pin
Voltage on V
s-(*) (†)
V
OUT (*)(†)
pin
V
SENSE (‡)
Operating temperature
Storage temperature
Package power dissipation
- SOT23-5
NOTES:
(*) with respect to GND pin
(†) voltage not to exceed 20V
(‡) V
SENSE
= V
S+
- V
S-
-0.6V to 20V
-0.6V to V
S+
+0.5V
-0.6V to +0.5V
-40 to 85°C
-55 to 150°C
(T
A
= 25°C)
- 450mW
Pinout information
Pin name
N/C
GND
V
OUT
V
S
_
V
S+
Pin function
Not internally connected
Ground
Voltage output referenced to GND. Intended to
drive high impedance loads
High impedance negative sense voltage input
Supply and positive sense voltage input
Issue 6 - March 2008
© Zetex Semiconductors plc 2008
2
www.zetex.com
ZXCT1022
Electrical characteristics test conditions T
amb
= 25°C, V
IN
= 15V
Symbol
V
IN
V
OUT
Parameter
V
CC
range
Output voltage
V
SENSE
= 0V
V
SENSE
= 10mV
V
SENSE
= 30mV
V
SENSE
= 100mV
R
OUT
T
C (*)
I
Q
V
SENSE (†)
I
SENSE
Acc
Gain
BW
Output resistance
Output temperature
coefficient
Ground pin current
Sense voltage
Load pin current
Accuracy
V
OUT
/ V
SENSE
Bandwidth
V
SENSE
= 0V
V
IN
= 20V
V
SENSE
= 0V
V
SENSE
= 10mV
V
SENSE
= 10mV
V
SENSE
= 10mV
V
SENSE
= 100mV
-3
97
100
300
2
0
Conditions
Min.
2.5
0
0.97
2.91
9.7
10
30
1.0
3.0
10.0
15
50
25
Limits
Typ.
Max.
20
100
1.03
3.09
10.3
20
300
35
180
(‡)
100
3
103
V
mV
V
V
V
k
ppm
A
mV
nA
%
V/V
kHz
MHz
Unit
NOTES:
(*) T
C
limits are determined by characterization
(†) V
SENSE
= V
IN
- V
LOAD
(‡) For linear operation maximum V
SENSE
is limited by operating voltage and is approximately:
-
V
SENSE
=
----------------------
(
V
IN
–
2
)
100
Issue 6 - March 2008
© Zetex Semiconductors plc 2008
3
www.zetex.com