TSZ121 datasheet(19/38 Pages) STMICROELECTRONICS

19 / 38 page

TSZ121, TSZ122, TSZ124

Application information

DocID023563 Rev 5

19/38

5.2

Operating voltages

TSZ121, TSZ122, and TSZ124 devices can operate from 1.8 to 5.5 V. The parameters are

fully specified for 1.8 V, 3.3 V, and 5 V power supplies. However, the parameters are very

stable in the full VCC range and several characterization curves show the TSZ121, TSZ122,

and TSZ124 device characteristics at 1.8 V and 5.5 V. Additionally, the main specifications

are guaranteed in extended temperature ranges from -40 to 125 ° C.

5.3

Input pin voltage ranges

TSZ121, TSZ122, and TSZ124 devices have internal ESD diode protection on the inputs.

These diodes are connected between the input and each supply rail to protect the input

MOSFETs from electrical discharge.

If the input pin voltage exceeds the power supply by 0.5 V, the ESD diodes become

conductive and excessive current can flow through them. Without limitation this over

current can damage the device.

In this case, it is important to limit the current to 10 mA, by adding resistance on the input

pin, as described in Figure 42: "Input current limitation".

Figure 42: Input current limitation

5.4

Rail-to-rail input

TSZ121, TSZ122, and TSZ124 devices have a rail-to-rail input, and the input common

mode range is extended from (VCC-) - 0.1 V to (VCC+) + 0.1 V.

TSZ121 Datasheet(PDF) 19 Page - STMicroelectronics