ADA4522-1 datasheet(21/32 Pages) AD

21 / 32 page

LTC2063/LTC2064/LTC2065

Rev. C

For more information www.analog.com

APPLICATIONS INFORMATION

90V High Side Current Sense

This micropower precision LTC2063 high side current

sense circuit measures currents from 100μA to 250mA

over a 4.5V to 90V input voltage range.

The output of this circuit is:

VOUT =

ROUT •RSHUNT

RIN

ISENSE = 500 •ISENSE

The LTC2063’s low typical input offset voltage of 1μV and

low input bias current of 3pA contribute output errors

that are much smaller than the error due to precision

limitations of the resistors used. Thus, output accuracy

is mainly set by the accuracy of the resistors RSENSE, RIN,

and ROUT.

The LT1389-4.096V reference, along with the bootstrap

circuit composed of M2, R3, and D1, establishes a very

low power isolated 3V rail that protects the LTC2063 from

reaching its absolute maximum voltage of 5.5V while

allowing for much higher input voltages.

Since the LTC2063’s gain-bandwidth product is 20kHz,

it is recommended to use this circuit to measure sig-

nals that are 2kHz or slower. Note that the output filter as

drawn will limit the frequency to 1.5Hz, which optimizes

for lowest noise. If this output filter bandwidth is too nar-

row, removing C2 leads to an output filter with 318Hz

bandwidth, created by C3 and ROUT.

VOUT = 10 • ISENSE

1mV TO 2.5V

VIN

4.5V TO 90V

2063 F11

49.9

0.1%

1N4148

REF

LT1389-4.096

3.3µF

22µF

100nF

10µF

499k

100k

RSENSE

0.1

ROUT

4.99k

0.1%

BSP322P

RIN

49.9

0.1%

BSP322P

ISENSE

100µA TO 250mA

LOAD

LTC2063

Figure 11. High Side Current Sense

ADA4522-1 数据表(PDF) 21 Page - Analog Devices

ADA4522-1 数据表(HTML) 21 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

数据表下载

链接网址

ADA4522-1 数据表(PDF) 21 Page - Analog Devices

ADA4522-1 数据表(HTML) 21 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

数据表 下载

链接网址

数据表下载