ZXCT1010
ENHANCED HIGH-SIDE CURRENT MONITOR
DESCRIPTION
The ZXCT1010 is a high side current sense monitor.
Using this device eliminates the need to disrupt the
ground plane when sensing a load current.
It is an enhanced version of the ZXCT1009 offering
reduced typical output offset and improved accuracy
at low sense voltage.
The wide input voltage range of 20V down to as low as
2.5V make it suitable for a range of applications. A
minimum operating current of just 4µA, combined
with its SOT23-5 package make suitable for portable
battery equipment.
FEATURES
•
•
•
•
•
•
•
•
Low cost, accurate high-side current sensing
Output voltage scaling
Up to 2.5V sense voltage
2.5V – 20V supply range
300nA typical offset current
3.5µA quiescent current
1% typical accuracy
SOT23 -5 package
APPLICATIONS
•
•
•
•
•
•
Battery chargers
Smart battery packs
DC motor control
Over current monitor
Power management
Programmable current source
APPLICATION CIRCUIT
ORDERING INFORMATION
DEVICE
ZXCT1010E5TA
REEL
SIZE
7”
TAPE
WIDTH
8mm
QUANTITY PER
REEL
3,000 units
PARTMARK
PACKAGE
101
SOT23-5
ISSUE 10 - JULY 2007
1
SEMICONDUCTORS
ZXCT1010
ABSOLUTE MAXIMUM RATINGS
Voltage on any pin
Continuous output current, I
OUT
,
Continuous sense voltage, V
SENSE2
,
Operating temperature, T
A,
Storage temperature
Package power dissipation
SOT23-5
-0.6V to 20V (relative to GND)
25mA
-0.5V to +5V
-40 to 85°C
-55 to 150°C
(T
A
= 25°C)
300mW
Operation above the absolute maximum rating may cause device failure.
Operation at the absolute maximum ratings, for extended periods, may reduce device reliability.
ELECTRICAL CHARACTERISTICS
Test Conditions T
A
= 25°C, V
in
= 5V, R
out
= 100Ω.
SYMBOL
V
in
I
out 1
PARAMETER
V
CC
Range
Output current
V
sense
= 0V
CONDITIONS
Min
2.5
0
85
0.975
1.95
9.7
LIMITS
Typ
0.3
100
1.00
2.00
10.0
3.5
0
UNIT
Max
20
10
115
1.025
2.05
10.3
8
2500
100
V
µA
µA
mA
mA
mA
µA
mV
nA
V
sense
= 10mV
V
sense
= 100mV
V
sense
= 200mV
V
sense
= 1V
I
q
V
sense 2
I
sense
-
Acc
Gm
Ground pin
current
Sense Voltage
V
sense
-
input current
Accuracy
Transconducta
nce,
I
out
/ V
sense
BW
Bandwidth
V
SENSE(DC)
= 10mV, Pin = -40dBm ‡
V
SENSE(DC)
= 100mV, Pin = -20dBm ‡
R
sense
= 0.1Ω
V
sense
= 200mV
V
sense
= 0V
-2.5
10000
2.5
%
µA/V
300
2
kHz
MHz
Includes input offset voltage contribution
V
SENSE
is defined as the differential voltage between V
SENSE+
and V
SENSE-
.
V
SENSE
= V
SENSE+
- V
SENSE-
= V
IN
- V
LOAD
= I
LOAD
x R
SENSE
3
-20dBm=63mVp-p into 50Ω
2
1
ISSUE 10 - JULY 2007
SEMICONDUCTORS
ZXCT1010
TYPICAL CHARACTERISTICS
ISSUE 10 - JULY 2007
3
SEMICONDUCTORS
ZXCT1010
PIN DESCRIPTION
Pin Name
V
sense
+
V
sense
-
I
out
GND
Pin Function
Supply voltage
Connection to load/battery
Output current, proportional to V
in
-V
load
Ground
CONNECTION DIAGRAM
SOT23-5
Package Suffix – E5
Top View
SCHEMATIC DIAGRAM
ISSUE 10 - JULY 2007
4
SEMICONDUCTORS
ZXCT1010
POWER DISSIPATION
The maximum allowable power dissipation of the
device for normal operation (Pmax), is a function of
the package junction to ambient thermal resistance
(θja), maximum junction temperature (Tjmax), and
ambient temperature (Tamb), according to the
expression:
P
max
= (Tj
max
– T
amb
) /
θ
ja
The device power dissipation, P
D
is given by the
expression:
P
D
=I
out
.(V
in
-V
out
) Watts
APPLICATIONS INFORMATION
The following lines describe how to scale a load
current to an output voltage.
V
sense
= V
in
- V
load
V
out
= 0.01 x V
sense
x R
out1
E.g.
A 1A current is to be represented by a 100mV output
voltage:
1)Choose the value of R
sense
to give 50mV > V
sense
>
500mV at full load.
For example V
sense
= 100mV at 1.0A. R
sense
= 0.1/1.0
=> 0.1 ohms.
2)Choose R
out
to give V
out
= 100mV, when V
sense
=
100mV.
Rearranging
1
for R
out
gives:
R
out
= V
out
/(V
sense
x 0.01)
R
out
= 0.1 / (0.1 x 0.01) = 100
Ω
TYPICAL CIRCUIT APPLICATION
Where R
load
represents any load including DC motors,
a charging battery or further circuitry that requires
monitoring, R
sense
can be selected on specific
requirements of accuracy, size and power rating.
ISSUE 10 - JULY 2007
5
SEMICONDUCTORS
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