Figure 55. Input bias current vs. common mode voltage Vcc = 5 V

-20

-10

0

10

20

30

40

50

60

70

-600

-500

-400

-300

-200

-100

0

100

200

300

400

500

600

Iibp

Vref=Vcc/2

Vsense=0V

Vcc=5V

Iibn

Vicm (V)

•

Gnd < Vicm < Vcc

In this manner, the TSC2011H is only powered by the power supply Vcc, and the iib currents are very close to 0

µA and do not have any impact on the current measurement.

•

-20 V < Vicm < Gnd

The TSC2011H is fully functional in this range of common mode voltage and has also been characterized.

As the high positive common mode voltage, in this specific range, the TSC2011H is also powered by the input,

see Figure 3.

Figure 56. Power supply when Vicm < Gnd

Most of the current is still due to the pin In+ as we can see on the iibp curve of Figure 7. The current is about - 300

µA, some of it being Vicm / (R4 + R1) and some other supplies the circuit, roughly 250 µA. A small part of the

current, coming from the common mode rail, is also due to the input In– in order to power the TSC2011H, in a

range of -100 µV.

TSC2010H, TSC2011H, TSC2012H

Application information

DS13791 - Rev 2

page 24/49