TP2111 datasheet(11/18 Pages) 3PEAK

11 / 18 page

TP2111/TP2111N/TP2112/TP2114

Nanopower 300nA, 1.8V, Rail-to-Rail Input/Output Op-amps

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REV1.0

are of equal length so that thermal conduction is in equilibrium. Keep heat sources on the PCB as far away from

amplifier input circuitry as is practical.

The use of a ground plane is highly recommended. A ground plane reduces EMI noise and also helps to maintain a

constant temperature across the circuit board.

BATTERY CURRENT SENSING

The Common Mode Input voltage Range of TP211x OPA series, which goes 0.3V beyond both supply rails, supports

their use in high-side and low-side battery current sensing applications. The low quiescent current (300nA, typical)

helps prolong battery life, and the rail-to-rail output supports detection of low currents.

The battery current (IDD) through the 10Ω resistor causes its top terminal to be more negative than the bottom terminal.

This keeps the Common Mode Input voltage below VDD, which is within its allowed range. The output of the OPA will

also be blow VDD, within its Maximum Output Voltage Swing specification.

VOUT

100k

1MΩ

To Load

OUT







TP2111

Figure 3

Instrumentation Amplifier

The TP211x OPA series is well suited for conditioning sensor signals in battery-powered applications. Figure 4 shows

a two op-amp instrumentation amplifier, using the TP211x OPA.

The circuit works well for applications requiring rejection of Common Mode noise at higher gains. The reference

voltage (VREF) is supplied by a low-impedance source. In single voltage supply applications, VREF is typically VDD/2.

VREF

VOUT

)(1

)

OUT

REF





½ TP2112

Figure 4

TP2111 Datasheet(PDF) 11 Page - 3PEAK INC.