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ZXCT1041
Bidirectional precision high-side current monitor
Description
The ZXCT1041 is a bidirectional precision highside current sense monitor. The output voltage
is proportional to the differential input voltage.
Direction of current flow is indicated by the
Flag pin.
The ZXCT1041 provides a fixed gain of 10 for
applications where minimal sense voltage is
required.
Features
• Bidirectional high side measurement
• Output voltage scaling x10
• 2.7V to 20V high side voltage
• 35µA quiescent current
• 1% typical accuracy
• SOT23-5 package
Pin connections
The very low offset voltage enables a typical
accuracy of 2% for sense voltages of only
10mV, giving better tolerances for small sense
resistors necessary at higher currents.
The wide input voltage range of 18V down to
as low as 2.7V make it suitable for a range of
applications.
A minimum operating current of just 40A,
combined with a SOT23-5 package makes this
part suitable for portable battery equipment.
Applications
• Battery management
• Over current monitor
• Battery gas gauging
• Motor control
Typical application circuit
R
V
+
IN
SENSE
VIN-
54
Flag
V
SENSE
V
-
SENSE
V
+
SENSE-
ZXCT1041
Flag
1
GND
V
OUT
3
V
OUT
V
OUT
V
SENSE
GND
+
2
Ordering information
Order code Package Partmark Reel size
(inches)
ZXCT1041E5TA SOT23-5 1041 7 8 3000
Issue 1 - November 2006 1 www.zetex.com
© Zetex Semiconductors plc 2006
Tape width
(mm)
Quantity
per reel
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Absolute maximum ratings
ZXCT1041
Voltage on V
Voltage on all other pins -0.6V to (V
Vsense [(V
SENSE
Operating temperature, T
SENSE-
+) - (V
and V
SENSE
SENSE+
-)] +/-6V
A
-0.6 to 20V
-40 to 125°C
SENSE+
/ V
SENSE-
) +0.6V
Storage temperature -55 to 150°C
Maximum junction temperature, T
Package power dissipation 300mW at T
Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for
extended periods, may reduce device reliability.
150°C
J
= 25°C (De-rate to zero at 150°C)
A
Recommended operating conditions
Parameter Min. Max. Units
V
SENSE±
Flag Current direction flag output 0 V
V
SENSE
V
OUT
T
A
Common-mode sense input range 2.7 20 V
SENSE±
V
Differential sense input voltage range 0 ±0.8 V
Output voltage range 0 V
SENSE±
-1.5 V
Ambient temperature range -40 125 °C
Pin function table
Pin Name Description
1 Flag This is the current direction pin. It is open collector and allows the logic high
level to be set independent of V
greater than V
SENSE-
2 GND Ground pin
3 OUT Output voltage pin
4V
SENSE+
This is the positive input of the current monitor. It also acts as the supply
voltage pin providing current for internal circuitry. The current through this
pin varies with differential sense voltage
5V
SENSE-
This is the negative input of the current monitor. The current through this
pin varies with differential sense voltage
SENSE+
voltage. Low indicates V
SENSE+
is
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Electrical characteristics
ZXCT1041
Test conditions TA = 25°C, V
SENSE
+ = 10V, V
SENSE
= 100mV
Symbol Parameter Conditions Min. Typ. Max. Units
I
Q
I
SENSE
I
SENSE
V
OUT
Ground pin current 15 35 50 µA
+V
-V
Output voltage
+ input current V
SENSE
- input current V
SENSE
SENSE
SENSE
V
SENSE
= 0V 10 17 24 µA
= 0V 10 17 24 µA
= +150mV 1.55 1.5 1.45 V
[flag high]
= +100mV 1.02 1 0.98 V
SENSE
= +30mV 309 300 291 mV
SENSE
= 0V 0 15 mV
SENSE
= -30mV 285 300 315 mV
SENSE
= -100mV 0.95 1 1.05 V
SENSE
= -150mV 1.42 1.50 1.58 V
SENSE
= ±100mV 30 ppm/ºC
SENSE
V
OUT
[flag low] V
TC V
variation with
OUT
V
V
V
V
V
V
temperature
Gain V
OUT/VSENSE
10
Accuracy Total output error
V
= 100mV -2 2 %
SENSE
(Gain + offset)
Accuracy Total output error
V
SENSE
= -100mV -5 5 %
(Gain + offset)
BW Bandwidth V
CMRR V
SENSE+
common
SENSE(DC)
V
SENSE(AC)
VIN = 2.7 to 20V TBD 60 dB
= 100mV
= 63mV
300 kHz
PP
mode rejection ratio
Flag TP Flag trip point Referred to V
V
FL
Flag low output
I
= 100A60200mV
SINK
SENSE
-2.5 +2.5 mV
voltage
I
FH
Flag high leakage
VOH = 5V 1 A
current
NOTES:
(a) - V
(b) Temperature dependent measurements are extracted from characterisation and simulation results.
SENSE
= "V
SENSE+
" - "V
SENSE-
"
Issue 1 - November 2006 3 www.zetex.com
© Zetex Semiconductors plc 2006