Diodes ZXCT1041 User Manual

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 external
components are 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

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.

Applications

• Battery management

• Over current monitor

• Battery gas gauging

• Motor control

Typical application circuit

-

Pin connections

Flag

S-

R

V

+

IN

S+

S

54

S-

ZXCT1041

V

IN

Flag

1

GND

OUT

S+

GND

2

OUT

3

V

OUT

Ordering information

Order code Package Partmark Reel size

(inches)

ZXCT1041E5TA SOT23-5 1041 7 8 3000

Issue 2 - January 2008 1 www.zetex.com

© Zetex Semiconductors plc 2008

Tape width

(mm)

Quantity

per reel

Absolute maximum ratings

ZXCT1041

Voltage on VS- and V

S+

Voltage on all other pins -0.6V to (V

V

[(VS+) - (VS-)] +/-6V

sense

Operating temperature, T

A

-0.6 to 20V

-40 to 125°C

or VS-) +0.6V

S+

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

S±

Flag Current direction flag output 0 V

V

SENSE

V

OUT

T

A

Common-mode sense input range 2.7 20 V

S±

V

Differential sense input voltage range 0 ±0.8 V

Output voltage range 0 VS± -1.5 V

Ambient temperature range -40 125 °C

Pin function table

Pin Name Description

1Flag

2 GND Ground pin

3 OUT Output voltage pin

4 S+ This is the positive input of the current monitor. It also acts as the supply

5 S- This is the negative input of the current monitor. The current through this

This is the current direction pin. It is open collector and allows the logic high
level to be set independent of V

voltage. Low indicates VS+ is greater than V

S+

voltage pin providing current for internal circuitry. The current through this
pin varies with differential sense voltage

pin varies with differential sense voltage

S-

Issue 2 - January 2008 2 www.zetex.com

© Zetex Semiconductors plc 2008

Electrical characteristics

ZXCT1041

Test conditions TA = 25°C, VS+ = 10V, V

SENSE

= 100mV

Symbol Parameter Conditions Min. Typ. Max. Units

I

I

I

V

Q

S+

S-

OUT

Ground pin current 15 35 50 µA

VS+ input current V

VS- input current V

Output voltage

V

= 0V 10 17 24 µA

SENSE

= 0V 10 17 24 µA

SENSE

= +150mV 1.55 1.5 1.45 V

SENSE

[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

TC V

[flag low] V

variation with

OUT

V

V

V

V

V

V

temperature

Gain V

OUT/VSENSE

10

Accuracy Total output error

V

= 100mV ±2 %

SENSE

(Gain + offset)

Accuracy Total output error

V

SENSE

= -100mV ±5 %

(Gain + offset)

BW Bandwidth V

CMRR V

common mode

S+

SENSE(DC)

V

SENSE(AC)

VIN = 2.7 to 20V 60 dB

= 100mV
= 63mV

300 kHz

PP

rejection ratio

Flag TP Flag trip point Referred to V

V

FL

Flag low output

I

= 100␮A60200mV

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.

= "VS+" - "VS-"

SENSE

Issue 2 - January 2008 3 www.zetex.com

© Zetex Semiconductors plc 2008

Typical characteristics

ZXCT1041

Conditions V

SENSE

+=10V, V

=100mV, TA=25°C unless otherwise stated.

SENSE

Issue 2 - January 2008 4 www.zetex.com

© Zetex Semiconductors plc 2008