TLE4275QKTTRQ1 (Texas Instruments, Automotive-Grade LDO) – Input Characteristics Summary

Operating Input Voltage Range

• Normal DC input: 5.5 V ~ 42 V.
• Absolute maximum transient withstand voltage: 45 V (capable of withstanding surges such as automotive load dump).

Transient and Dynamic Response

• Input transient rejection: under cold crank or 1 V/µs input step, output deviation is within ±2%, no external clamp required.

Input Polarity Protection

• Built-in reverse polarity protection (specific to legacy chips); reverse connection of power supply does not damage the device, but attention must be paid to reverse current path limitations.

Input Quiescent Power Consumption

• Self-consumption: IQ typical 100 µA (@ Iout = 1 mA), maximum about 200 µA (the Supply Current_max of 22 mA in the datasheet is an extreme non-steady-state value).
• Suitable for always-on applications (e.g., standby MCU, CAN transceivers), with low burden on the battery.

Input Capacitor Requirements

• Legacy chip does not specify clear requirements for input capacitance; typically, a ≥0.1 µF ceramic capacitor should be placed close to the input for high-frequency bypass, along with a larger electrolytic capacitor (10 µF~47 µF) to suppress ringing caused by long-wire inductance.

Key Selection Constraints

• Minimum dropout: 0.5 V @ 300 mA, so for 5 V output, the input must be ≥ 5.5 V (consistent with the minimum operating voltage).
• Power dissipation at high input voltage: for example, at Vin = 24 V, Iout = 300 mA, dissipation is approximately (24-5)×0.3 = 5.7 W, exceeding the heat dissipation capability of the TO-263 package; large copper areas or active cooling are required, otherwise the maximum input voltage or output current must be limited.