|
LT1787_15 Datasheet, PDF (1/16 Pages) Linear Technology – Precision, High Side Current Sense Amplifiers | |||
|
LT1787/LT1787HV
Precision, High Side
Current Sense Amplifiers
FEATURES
â Input Offset Voltage: 75µV (Max)
â 60V Supply Operation (LT1787HV)
â 12-Bit Dynamic Range
â Operating Current: 60µA
â User-Selectable External Sense Resistor
â Bidirectional High Side Current Sensing
â Unidirectional or Bidirectional Output
â Input Noise Filtering
â â40°C to 125°C Operating Temperature Range
â Available in 8-Lead SO and MSOP Packages
U
APPLICATIO S
â Battery Monitoring
â Power Monitoring
â Portable Phones
â Cellular Phones
â Portable Test/Measurement Systems
â Battery-Operated Systems
DESCRIPTIO
The LT®1787 is a complete micropower precision high
side current sense amplifier. The LT1787 monitors bidi-
rectional currents via the voltage across an external sense
resistor. A current or voltage output indicates the direction
and magnitude of the sense current. The LT1787 delivers
greater than a 12-bit dynamic range with ultralow 40µV
input offset voltage compared to a typical 250mV full-
scale input voltage. A fixed gain of 8 is set by onboard
precision resistors. Input signal filtering is easily imple-
mented with a capacitor between the FILâ and FIL+ pins.
The LT1787HV operates from 2.5V to 60V total supply
voltage and the LT1787 operates from 2.5V to 36V total
supply voltage. Both versions have a PSRR in excess of
120dB. The LT1787/LT1787HV draw only 60µA and are
available in 8-lead SO and MSOP packages.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
12-Bit Dynamic Resolution Unidirectional Output into LTC®1286 ADC
TO
LOAD
RSENSE
I = 100A 0.0016â¦
1 FILâ
FIL+ 8
2 VSâ LT1787HV VS+ 7
3
DNC
4
VEE
VBIAS 6
ROUT
20k 5
VOUT
VOUT = VBIAS + (8 ⢠ILOAD ⢠RSENSE)
C2
0.1µF
2.5V TO 60V
R1
C1
15k
1µF
VREF VCC
+IN
CS
LTC1286 CLK
âIN
GND DOUT
LT1634-1.25
5V
TO µP
1787 TA01
Input Offset Voltage vs Supply Voltage
50
40
30
20
10
0
â10
â20
â30
â40
â50
0
10 20 30 40 50 60
TOTAL SUPPLY VOLTAGE (V)
1787 TA01b
1787fc
1
|
▷ |