A Product Line of
Diodes Incorporated
ZXCT1030
HIGH-SIDE CURRENT MONITOR WITH COMPARATOR
Description
The ZXCT1030 is a high side current sense monitor
containing an internal reference and comparator with a non-
latching output. Using this device eliminates the need to
disrupt the ground plane when sensing a load current.
The wide input voltage range of 20V down to as low as 2.2V
make it suitable for a range of applications. Dynamics and
supply current are optimized for the processing of fast pulses,
associated with switch mode applications
.
Pin Assignments
V
CC
V
SENSE-
V
SENSE+
GND
V
COMP_OUT
V
OUT
Vref_out
V
COMP_IN
Features
•
•
•
•
•
•
•
Low cost, accurate high-side current sensing
Output voltage scaling
Up to 18V output
2.2V - 20V supply range
Voltage reference on chip
Comparator on chip
SO8 package
Applications
•
•
•
•
•
Battery chargers
Electronic fuse
DC motor control
Over current monitor
Power management
Inrush current limiting
•
Typical Application Circuit
ZXCT1030
Document number: DS32161 Rev. 4 - 2
1 of 7
www.diodes.com
June 2010
© Diodes Incorporated
A Product Line of
Diodes Incorporated
ZXCT1030
Pin Description
Pin Name
V
CC
V
SENSE-
V
SENSE+
GND
V
COMP_IN
V
REF_OUT
V
OUT
V
COMP_OUT
Function
Supply voltage
Negative sense input
Positive sense input
Ground
Comparator input, usually a ratio of the
reference or other control signal
Reference output
Current monitor output voltage
Open collector comparator output
Absolute Maximum Ratings
Parameter
Voltage on any pin
Operating Temperature
Storage Temperature
Package Power Dissipation
SO8
Rating
-0.6 and V
CC
+0.6
-40 to 85
-55 to 125
(T
AMB
= 25)
700
Unit
V
°C
°C
°C
mW
Recommended Operating Conditions
Parameter
V
CC
V
SENSE+
V
SENSE
(a)
V
OUT
V
COMP_IN
T
AMB
Min
2.2
2.2
10
0
0.005
-40
Max
20
V
CC
500
V
SENSE-
-1V
10
85
Units
V
V
mV
V
V
°C
ZXCT1030
Document number: DS32161 Rev. 4 - 2
2 of 7
www.diodes.com
June 2010
© Diodes Incorporated
A Product Line of
Diodes Incorporated
ZXCT1030
Electrical Characteristics (ZXCT1030N8)
– Test conditions T
AMB
= 25°C, V
IN
= V
CC
= 15V, R
COMP
= 10kΩ,
V
COMP
_
SUPPLY
= 5V unless otherwise stated.
Symbol
V
CC
V
SENSE
+
V
CC
Range
Sense+ Range
V
SENSE
= 0
V
SENSE
= 10
V
SENSE
= 30
V
SENSE
= 50
V
SENSE
= 100
V
SENSE
= 500
V
SENSE -
= 15V,
V
OUT
= 1V
Parameter
Condition
Min.
2.2
2.2
0
88
284
480
970
4500
1.2
Typ.
Max.
20
V
CC
2
100
300
500
1000
5000
1.5
30
V
SENSE -
= 15V
V
SENSE-
= 14.9V
V
CC
= 15V
V
COMP
_
SUPPLY
= 5V
V
COMP
_
IN
= V
REF
V
SENSE
= 10mV
V
SENSE
= 100mV
V
SENSE
= 100mV
V
SENSE
= 10mVp-p
V
SENSE
= 100mVp-p
170
270
48
70
350
90
220
10
112
316
520
1030
5500
1.8
Unit
V
V
OUT
Output Voltage
mV
R
OUT
V
OUT
T
C
I
CC
I
SENSE
+
I
SENSE
-
V
CM(MIN)
(B)
Output Resistance
V
OUT
Temperature Coefficient
Supply Current
V
SENSE
+ Input Current
V
SENSE
- Input Current
Minimum Active Common Mode Voltage
kΩ
ppm/°C
µA
µA
nA
2.8
V
A
CC
GAIN
BW
Accuracy
V
OUT
/V
SENSE
Bandwidth
-3
9.7
10.0
3
6
3
10.3
%
MHz
10
V
mV
nA
ns
mV
COMPARATOR
Input Voltage
V
COMP_IN
Hysteresis
V
H
Input Bias
I
B
Propagation Delay
T
D
Output Voltage Low
V
OL
V
OH
Output Voltage High
Vol = 0.4V
0.005
5
30
15
80
100
150
150
200
V
COMP_
SUPPLY
Output Sink Current
I
OL
Output High Leakage Current
I
OH
Voltage Reference
V
REF
Delta V
REF
T
C
PSR
Notes:
2
1.0
mA
µA
V
mV
ppm/°C
%/V
Change in V
REF
Supply Rejection
Reference Current =
+300µA to -5µA
I
SOURCE
5µA to
I
SINK
300µA
1.200
1.240
10
30
0.01
1.280
(a) (V
SENSE
+
) – (V
SENSE
-)
(b) Level of V
SENSE
+ where comparator output defaults to ‘off’.
ZXCT1030
Document number: DS32161 Rev. 4 - 2
3 of 7
www.diodes.com
June 2010
© Diodes Incorporated
A Product Line of
Diodes Incorporated
ZXCT1030
Voltage output current monitor
Referring to the block diagram, the current monitor takes the small voltage developed across the sense resistor (V
SENSE
)
and transfers it from the large common mode supply voltage to a ground referenced signal with a gain of 10. The sense
input common mode range is 2.2V to 20V. In this range, a linear output voltage is delivered.
Reference
The bandgap reference allows the comparator to compare the translated V
SENSE
with threshold value chosen by the user
which can be any voltage from 0 to 1.24V, configured by two external resistors which forms V
COMP
_
IN
.
The output current which can be drawn from the comparator reference (I
REF
source) is limited to 5μA, making
potentiometers
≥250kΩ
suitable for setting a threshold level. Where a lower potentiometer resistor value is used, an
additional resistor value should be inserted between V
REF
and V
CC
to maintain sufficient current for the reference.
(as shown in Figure 1).
Figure 1: External Resistor for Reference Level
The voltage reference has a maximum current sink capability. This magnitude of current will be influenced by the value of
R1 which is inserted between V
REF
and V
CC
. The value of current flowing through R1 can be expressed as:
I = (V
CC
-V
REF
) / R1
Comparator
The open collector output is active low and is asserted when V
SENSE
x 10 (V
OUT
) > V
COMP
_
IN
. It can be connected to any
voltage rail up to V
IN
via a pull-up resistor. Suggest values for the resistor are in the range of 10-100kΩ.
In the case where high load currents or a short circuit occurs, thus reducing the common mode signals (V+, V-) typically
below 2.2V, the comparator will default to the asserted state. This can eliminate a closed loop system 'latch-up' condition,
allowing the controller to remove the applied power.
Stability
To ensure stable operation of the ZXCT1030, it is recommended a decoupling capacitor is placed across the V
CC
and
ground connections. A ceramic 10µF will be adequate.
ZXCT1030
Document number: DS32161 Rev. 4 - 2
5 of 7
www.diodes.com
June 2010
© Diodes Incorporated
stm32/stm8
京公网安备 11010802033920号
EEWORLD
