TSU101 datasheet(22/33 Pages) STMICROELECTRONICS

22 / 33 page

Application information

TSU101, TSU102, TSU104

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DocID024317 Rev 2

Figure 40. Potentiostat schematic using the TSU101 (or TSU102)

4.8

Fast desaturation

When the TSU101, TSU102, and TSU104 operational amplifiers go into saturation mode,

they take a short period of time to recover, typically thirty microseconds. When recovering

after saturation, the TSU10x series does not exhibit any voltage peaks that could generate

issues (such as false alarms) in the application (see Figure 17). This is because the internal

gain of the amplifier decreases smoothly when the output signal gets close to the VCC+ or

VCC- supply rails (see Figure 15 and Figure 16).

Thus, to maintain signal integrity, the user should take care that the output signal stays at

100 mV from the supply rails.

With a trans-impedance schematic, a voltage reference can be used to keep the signal

away from the supply rails.

4.9

Using the TSU10x series in comparator mode

The TSU10x series can be used as a comparator. In this case, the output stage of the

device always operates in saturation mode. In addition, Figure 4 shows the current

consumption is not bigger and even decreases smoothly close to the rails. The TSU101,

TSU102, and TSU104 are obviously operational amplifiers and are therefore optimized to

be used in linear mode. We recommend to use the TS88 series of nanopower comparators

if the primary function is to perform a signal comparison only.

TSU101 Datasheet(PDF) 22 Page - STMicroelectronics