ZXCT1041
Bidirectional precision high-side current monitor
Description
The ZXCT1041 is a bidirectional precision high-
side 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
external
components are required.
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 20V down to
as low as 2.7V make it suitable for a range of
applications.
A minimum operating current of just 40 A,
combined with a SOT23-5 package makes the
ZXCT1041 particularly suitable for portable
battery equipment.
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
Applications
•
•
•
•
Battery management
Over current monitor
Battery gas gauging
Motor control
Typical application circuit
V
IN
+
R
S
V
IN
-
Pin connections
4
5
Flag
GND
OUT
S-
S+
S-
ZXCT1041
1
Flag
GND
OUT
3
S+
2
V
OUT
Ordering information
Order code
ZXCT1041E5TA
Package
SOT23-5
Partmark
1041
Reel size
(inches)
7
Tape width
(mm)
8
Quantity
per reel
3000
Issue 2 - January 2008
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ZXCT1041
Absolute maximum ratings
Voltage on V
S-
and V
S+
Voltage on all other pins
V
sense
[(V
S+
) - (V
S-
)]
Operating temperature, T
A
Storage temperature
Maximum junction temperature, T
J
Package power dissipation
-0.6 to 20V
-0.6V to (V
S+
or V
S-
) +0.6V
+/-6V
-40 to 125°C
-55 to 150°C
150°C
300mW at T
A
= 25°C (De-rate to zero at 150°C)
Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings, for
extended periods, may reduce device reliability.
Recommended operating conditions
Parameter
V
S±
Flag
V
SENSE
V
OUT
T
A
Common-mode sense input range
Current direction flag output
Differential sense input voltage range
Output voltage range
Ambient temperature range
Min.
2.7
0
0
0
-40
Max.
20
V
S±
±0.8
V
S±
-1.5
125
Units
V
V
V
V
°C
Pin function table
Pin
1
2
3
4
Name
Flag
GND
OUT
S+
Description
This is the current direction pin. It is open collector and allows the logic high
level to be set independent of V
S+
voltage. Low indicates V
S+
is greater than V
S-
Ground pin
Output voltage pin
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
This is the negative input of the current monitor. The current through this
pin varies with differential sense voltage
5
S-
Issue 2 - January 2008
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ZXCT1041
Electrical characteristics
Test conditions T
A
= 25°C, V
S+
= 10V, V
SENSE
= 100mV
Symbol
I
Q
I
S+
I
S-
V
OUT
Parameter
Ground pin current
V
S+
input current
V
S-
input current
Output voltage
[flag high]
V
SENSE
= 0V
V
SENSE
= 0V
V
SENSE
= +150mV
V
SENSE
= +100mV
V
SENSE
= +30mV
V
SENSE
= 0V
[flag low]
V
SENSE
= -30mV
V
SENSE
= -100mV
V
SENSE
= -150mV
V
OUT
TC
Gain
Accuracy
Accuracy
BW
CMRR
Flag TP
V
FL
I
FH
V
OUT
variation with
temperature
V
OUT
/V
SENSE
Total output error
(Gain + offset)
Total output error
(Gain + offset)
Bandwidth
V
S+
common mode
rejection ratio
Flag trip point
Flag low output
voltage
Flag high leakage
current
V
SENSE
= 100mV
V
SENSE
= -100mV
V
SENSE(DC)
= 100mV
V
SENSE(AC)
= 63mV
PP
V
IN
= 2.7 to 20V
Referred to V
SENSE
I
SINK
= 100 A
V
OH
= 5V
-2.5
60
300
60
+2.5
200
1
V
SENSE
= ±100mV
Conditions
Min.
15
10
10
1.55
1.02
309
0
285
0.95
1.42
300
1
1.50
30
10
±2
±5
%
%
kHz
dB
mV
mV
A
Typ.
35
17
17
1.5
1
300
Max.
50
24
24
1.45
0.98
291
15
315
1.05
1.58
Units
µA
µA
µA
V
V
mV
mV
mV
V
V
ppm/ºC
NOTES:
(a) V
SENSE
= "V
S+
" - "V
S-
"
(b) Temperature dependent measurements are extracted from characterisation and simulation results.
Issue 2 - January 2008
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ZXCT1041
Typical characteristics
Conditions V
SENSE
+=10V, V
SENSE
=100mV, T
A
=25°C unless otherwise stated.
Issue 2 - January 2008
© Zetex Semiconductors plc 2008
4
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ZXCT1041
Typical characteristics
Conditions V
SENSE
+=10V, V
SENSE
=100mV, T
A
=25°C unless otherwise stated.
FLAG V
CC
= 5V
I
GND
(
µ
A)
8
R
FLAG
= 50k
6
Voltage (V)
300
250
200
150
100
50
4
2
0
-0.15
FLAG V
CC
= 5V
R
FLAG
= 50k
Flag Current 100
µ
A
2
0
-0.8 -0.6 -0.4 -0.2
V
SENSE
(V)
0.0
0.2
0.4
0.6
0.8
V
FLAG
(V)
4
-0.10
-0.05
V
SENSE
(V)
0.00
0.05
0.10
0.15
V
OUT
& V
FLAG
v Sense Voltage
700
700
I
GND
& V
FLAG
v Sense Voltage
Sense+ Pin Current (
µ
A)
600
500
400
300
200
100
Sense- Pin Current (
µ
A)
T
A
= -40°C to 125°C
600
500
400
300
200
100
0
-0.8 -0.6 -0.4 -0.2
T
A
= -40°C to 125°C
0
-0.8 -0.6 -0.4 -0.2
V
SENSE
(V)
0.0
0.2
0.4
0.6
0.8
V
SENSE
(V)
0.0
0.2
0.4
0.6
0.8
I
SENSE+
v Sense Voltage
Output Voltage Error (mV)
0
150
100
50
0
-50
-100
-150
-10
I
SENSE-
v Sense Voltage
Gain Error (%)
-5
-10
-15
5
10
Output Load Resistance (
Ω
)
10
6
10
7
10
8
Output Load Current (
µ
A))
-5
0
5
10
Error v Resistive Loading
Error v Current Loading
Issue 2 - January 2008
© Zetex Semiconductors plc 2008
5
www.zetex.com
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