ZETEX ZXCT1022

ZXCT1022
LOW OFFSET HIGH-SIDE CURRENT MONITOR
DESCRIPTION
APPLICATIONS
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.
• Battery chargers
• Smart battery packs
• DC motor control
The ZXCT1022 provides a fixed gain of 100 for
applications where minimal sense voltage is required.
• Over current monitor
• Power management
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.
• Level translating
• Programmable current source
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
TYPICAL CIRCUIT APPLICATION
• Accurate high-side current sensing
• Output voltage scaling
• 2.5V – 20V supply range
• 25␮A quiescent current
• 1% typical accuracy
• SOT23-5 package
ORDERING INFORMATION
DEVICE
REEL
SIZE
TAPE
WIDTH
QUANTITY PER
REEL
7”
8mm
3,000 units
ZXCT1022E5TA
DEVICE MARKING
1022
PROVISIONAL ISSUE J - APRIL 2004
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SEMICONDUCTORS
ZXCT1022
Absolute Maximum Ratings
Voltage on any pin
Vsense
-0.6V to 20V
-0.6V to Vin + 0.5V
Operating temperature
-40 to 85°C
Storage temperature
-55 to 150°C
Package power dissipation
(TA = 25°C)
SOT23
450mW
ELECTRICAL CHARACTERISTICS Test Conditions TA = 25°C, Vin = 15V
SYMBOL
PARAMETER
CONDITIONS
LIMITS
Min
Typ
2.5
UNIT
Max
V in
V CC range
V out
Output voltage
V sense = 0V
0
30
100
mV
(ZXCT1022)
V sense = 10mV
0.97
1.0
1.03
V
V sense = 30mV
2.91
3.0
3.09
V
9.7
10.0
10.3
V
10
15
20
50
300
V sense = 100mV
R out
Output resistance
Tc
Output temperature
coefficient
Iq
Ground pin current
V sense (2)
Sense voltage
I sense
Load pin input
current
Acc
Accuracy
V sense = 10mV
-3
Gain
V out / V sense
Bandwidth
V sense = 10mV
0.97
BW
V sense = 0V
20
25
0
V sense = 10mV
V sense = 100mV
1.0
35
V
K⍀
ppm
␮A
1.5
V
100
nA
3
%
1.03
V
300
kHz
2
MHz
NOTES
(2)
Vsense= Vin - Vload
TC Limits are determined by characterization.
PROVISIONAL ISSUE J - APRIL 2004
SEMICONDUCTORS
2
ZXCT1022
TYPICAL CHARACTERISTICS
PROVISIONAL ISSUE J - APRIL 2004
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SEMICONDUCTORS
ZXCT1022
TYPICAL CHARACTERISTICS
BLOCK DIAGRAM
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SEMICONDUCTORS
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ZXCT1022
Application information
The ZXCT1022 has a fixed dc voltage gain of 100. No external scaling resistors are required for the output. Output
voltage is simply defined as:
Vout = 100 x Vsense (V)
Where Vsense = Vin - VLoad
PCB trace shunt resistor for low cost solution
The figure below shows a PCB layout suggestion for a low cost solution where a PCB resistive trace in
replacement for a conventional shunt resistor, can be used. The resistor section is 25mm x 0.25mm giving
approximately 150mΩ using 1 oz copper. Smaller resistances can be used if required.
GND
Load
Total circuit solution: 1 component. Shows area of 150mΩ sense resistor
compared to SOT23 package.
Practical tolerance of the PCB resistor will be around 5% depending on
manufacturing methods.
PINOUT
PIN NAME
PIN FUNCTION
N/C
Not internally connected
GND
Ground
V out
Voltage output referenced to GND. Intended to
drive high impedance loads
Load
High impedance negative sense voltage input
V in
Supply and positive sense voltage input
Top view
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SEMICONDUCTORS
ZXCT1022
PACKAGE DIMENSIONS SOT23-5
PACKAGE DIMENSIONS
DIM
Millimetres
Inches
MIN
MAX
MIN
MAX
A
0.90
1.45
0.035
0.057
A1
0.00
0.15
0.00
0.006
A2
0.90
1.3
0.035
0.051
b
0.35
0.50
0.014
0.020
C
0.09
0.20
0.0035
0.008
D
2.80
3.00
0.110
0.118
E
2.60
3.00
0.102
0.118
E1
1.50
1.75
0.059
0.069
e
0.95 REF
0.037 REF
e1
1.90 REF
0.075 REF
L
0.10
0.60
0.004
0.024
a°
0
10
0
10
© Zetex plc 2004
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Fields New Road, Chadderton
Oldham, OL9 8NP
United Kingdom
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[email protected]
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Fax: (1) 631 360 8222
[email protected]
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Fax: (852) 24250 494
[email protected]
Telephone (44) 161 622 4444
Fax: (44) 161 622 4446
[email protected]
These offices are supported by agents and distributors in major countries world-wide.
This publication is issued to provide outline information only which (unless agreed by the Company in writing) may not be used, applied or reproduced
for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. The Company
reserves the right to alter without notice the specification, design, price or conditions of supply of any product or service.
For the latest product information, log on to www.zetex.com
PROVISIONAL ISSUE J - APRIL 2004
SEMICONDUCTORS
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SCZXLD1022DSH