LT1990 Datasheet, PDF (1/16 Pages) Linear Technology – 250V Input Range G = 1, 10, Micropower, Difference Amplifier

U
APPLICATIO S
■ _{Pin Selectable Gain of 1 or 10}
■ _{High Common Mode Voltage Range:}
85V Window (V_S = 5V, 0V)
±250V (V_S = ±15V)
■ _{Common Mode Rejection Ratio: 70dB Min}
■ _{Input Protection to ±350V}
■ _{Gain Error: 0.28% Max}
■ _{PSRR: 82dB Min}
■ _{High Input Impedance: 2MΩ Differential,}
500kΩ Common Mode
■ _{Micropower: 120µA Max Supply Current}
■ _{Wide Supply Range: 2.7V to 36V}
■ _{–3dB Bandwidth: 100kHz}
■ _{Rail-to-Rail Output}
■ _{8-Pin SO Package}
FEATURES
■ _{Battery Cell Voltage Monitoring}
■ _{High Voltage Current Sensing}
■ _{Signal Acquisition in Noisy Environments}
■ _{Input Protection}
■ _{Fault Protected Front Ends}
■ _{Level Sensing}
■ _Isolation
LT1990
±250V Input Range
G = 1, 10, Micropower,
Difference Amplifier
DESCRIPTIO
The LT^®1990 is a micropower precision difference ampli-
fier with a very high common mode input voltage range. It
has pin selectable gains of 1 or 10. The LT1990 operates
over a ±250V common mode voltage range on a ±15V
supply. The inputs are fault protected from common
mode voltage transients up to ±350V and differential
voltages up to ±500V. The LT1990 is ideally suited for both
high side and low side current or voltage monitoring.
On a single 5V supply, the LT1990 has an adjustable 85V
input range, 70dB min CMRR and draws less than 120µA
supply current. The rail-to-rail output maximizes the dy-
namic range, especially important for single supplies as
low as 2.7V.
The LT1990 is specified for single 3V, 5V and ±15V
supplies over both commercial and industrial temperature
ranges. The LT1990 is available in the 8-pin SO package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
+V_SOURCE
–+
R_S
I_L
–12V ≤ V_CM ≤ 73V
V_OUT = V_REF ± (10 • I_L • R_S)
Full-Bridge Load Current Monitor
5V
LT1990
900k
7
IN
OUT
LT6650
GND FB
V_REF = 1.5V
54.9k
1nF
20k
1µF
2 ^1M
–
3 ^1M
+
4
40k
900k
40k
1
10k ₈
100k
6 _VOUT
10k ₅
100k
1990 TA01
1990f
1