SCLA043 April 2021 SN74HC00

3 Voltage Translation for Wireless Interface Modules

It is common to see asset trackers utilizing wireless interface modules. These modules often use UART for communication, and commonly are operating at a different logic voltage level from the primary system controller. The addition of a voltage level translator protects low-power system controllers and ensures accurate communication to the peripheral module.

Figure 3-1 Example 2-wire UART Voltage Translation Block Diagram

See more about this use case in the Logic Minute video Voltage Level Translation for UART Interface

Some devices support up to 5 Mbps UART communication; most are limited to 115 kbps or less
Translators enable communication when devices have mismatched logic voltage levels
Prevent damage to devices that cannot support higher voltage inputs
Improve data rates over discrete translation solutions
Protect controller while peripheral is not connected
[FAQ] How does a slow or floating input affect a CMOS device?
Need additional assistance? Ask our engineers a question on the TI E2E™ Logic Support Forum

Table 3-1 Recommended Parts

Part Number	Automotive Qualified	Voltage Translation Range	Features
SN74AXC2T245-Q1	✓	0.65 V — 3.6 V	Glitch-free power supply sequencing Outputs are disabled when either supply is 0 V Active translation architecture
SN74AXC2T245		0.65 V — 3.6 V
TXB0102		1.2 V — 3.6 V to 1.65 V— 5.5 V	Auto-bidirectional Active translation architecture
TXS0102-Q1	✓	1.2 V — 3.6 V to 1.65 V— 5.5 V	Auto-bidirectional Internal pull-up resistors Passive translation architecture

For more devices, browse through the online parametric tool where you can sort by desired voltage, channel numbers, and other features.