ZETEX ZXCT1081 Technical data

ZXCT1081 High voltage high-side current monitor

Description

The ZXCT1081 is a high side current sense monitor with a gain of 10 and a voltage output. Using this device eliminates the need to disrupt the ground plane when sensing a load current.

The wide input voltage range of 40V down to as low as 3V make it suitable for a range of applications; including systems operating from industrial 24-28V rails and power supplies.

The separate supply pin (V to continue functioning under short circuit conditions, giving an end stop voltage at the output.

For automotive applications the ZXCT1081 has a 60V transient capability and ambient temperature range of -40°C to 125°C.

) allows the device

CC

Features

• 3V to 40V continuous high side voltage

• Accurate high-side current sensing

• Output voltage scaling x10

• 4.5V to 12V V

• Low quiescent current:

• 80µA supply pin

• 30µA I

CC

SENSE+

range

Applications

• Automotive current measurement

• Industrial applications current measurement

• Battery management

• Over current monitor

• Power management

• Power adapters

• SOT23-5 package

• -40°C to 125°C ambient temperature range

Pin connections Typical application circuit

V

CC

GND

OUT

V

1

2

3

5

SENSE-

4

SENSE+

IN

V

CC

1

4

SENSE+

V

cc

ZXCT1081

GND

2

R

SENSE

5

SENSE

OUT

3

-

V

OUT

Ordering information

Device Package Part mark Reel size

(inches)

ZXCT1081E5TA SOT23-5 1081 7 8 3000

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Tape width

(mm)

Quantity per

reel

Absolute maximum ratings

Continuous voltage on SENSE+ and SENSE- -0.6V and 45V

Transient voltage on SENSE+ and SENSE- -0.6V and 65V

Voltage on all other pins -0.6V and 14V

ZXCT1081

Differential sense voltage, V

800mV

SENSE

Operating temperature -40°C to 125°C

Storage temperature -55°C to 150°C

Maximum junction temperature 85°C

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.

= 25°C (de-rate to zero at 125°C)

A

Recommended operating conditions

Parameter Min. Max. Units

V

IN

V

CC

V

SENSE

V

OUT

T

J

Common-mode sense+ input range 3 40

V

Supply voltage range 4.5 12 V

Differential sense input voltage range 0 0.15 V

Output voltage range 0 1.5 V

Ambient temperature range -40 125 °C

Pin function table

Pin Name Description

1V

CC

This is the analogue supply and provides power to internal circuitry

2 GND Ground pin

3 OUT Output voltage pin. NMOS source follower with 20µA bias to ground

4 SENSE+ This is the positive input of the current monitor and has an input range from

40V (60V transient) down to 3V. The current through this pin varies with differential sense voltage

5 SENSE- This is the negative input of the current monitor and has an input range

from 40V (60V transient) down to 3V

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Electrical characteristics

ZXCT1081

Test conditions TA = 25°C, VIN = 12V, VCC = 5 V, V

SENSE

(a)

= 100mV unless otherwise stated.

Symbol Parameter Conditions Min. Typ. Max. Units

I

CC

I

SENSE+

I

SENSE-

V

O(0)

V

O(10)

Gain

V

OUT

VCC supply current VCC = 12V 40 80 120 µA

SENSE+ input current 15 30 60 µA

SENSE- input current 10 40 80 nA

Zero V

SENSE

Output offset voltage

TC

(d)

⌬V

V

/⌬V

OUT

variation with

OUT

(a)

SENSE

error

(a)

(b)

(c)

V

SENSE

V

SENSE

V

SENSE

(a)

= 0V

(a)

= 10mV

(a)

= 10mV to 150mV

035mV

-30 +30 mV

9.95 10 10.05

30 ppm/°C

temperature

Acc Total output error -3 3 %

I

OH

I

OL

PSRR V

Output source current ⌬V

Output sink current ⌬V

supply rejection

CC

VCC = 4.5V to 12V 54 60 dB

= -30mV 1 mA

OUT

= +30mV 20 µA

OUT

ratio

CMRR Common-mode sense

= 40V to 3V 60 75 dB

V

IN

rejection ratio

BW -3dB small signal

bandwidth

V

SENSE

(a)

(AC)

= 10mV

PP

500 kHz

NOTES:

(a) V (b) The ZXCT1081 operates from a positive power rail and the internal voltage-current converter current flow is

(c) For V

(d) Temperature dependent measurements are extracted from characterization and simulation results.

= "V

SENSE

unidirectional; these result in the output offset voltage for V

SENSE

used. V

O(10)

" - "V

SENSE+

> 10mV, the internal voltage-current converter is fully linear. This enables a true offset to be defined and

is expressed as the variance about an output voltage of 100mV>

SENSE-

"

= 0V always being positive.

SENSE

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Typical characteristics

ZXCT1081

Test conditions unless otherwise stated: TA = 25°C, VCC = 5V, V

SENSE+

=12V, V

SENSE

= 100mV

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