STMicroelectronics L4947PD013TR

Overview

L4947PD013TR from STMicroelectronics is a monolithic 5V/0.5A very low-dropout linear voltage regulator in PowerSO-20 package, featuring integrated power-on reset with externally programmable delay, ±80V load dump protection, reverse voltage protection (–18V), short-circuit and thermal shutdown with hysteresis, and precise output voltage (5.0V ±4%) over –40°C to +125°C - designed for automotive microprocessor supply during cranking (down to 6V input).

For engineers reviewing the L4947PD013TR datasheet, L4947PD013TR pinout, L4947PD013TR application, or L4947PD013TR equivalent, key selection considerations include dropout voltage ≤0.75V at 500mA across temperature, reset threshold hysteresis of 50mV, external capacitor–programmed power-on delay (e.g., 10–30ms with 100nF), and compliance with automotive transient immunity requirements (load dump, field decay, low-energy spike).

Technical Context

The L4947PD013TR employs a lateral PNP pass transistor enabling ultra-low dropout (0.40V typ. at 25°C, 0.75V max. over full temperature range at 500mA) and stable operation down to 6V input - critical for automotive cranking conditions. Its internal architecture includes an error amplifier, reference generator, anti-saturation circuit, and three-stage gain path requiring external output capacitance (≥47µF, ESR <10Ω) for loop stability.

The reset function uses dual-voltage comparators with programmable delay via external capacitor Cd: power-on reset triggers when V_OUT crosses V_RT(on) = V_OUT – 0.04V, then asserts high after delay T_d; power-off reset asserts low instantly at V_RT(off) = V_OUT – 0.15V, providing 50mV hysteresis. Reset output saturation voltage is ≤0.40V at 1.6mA sink current.

Key Specifications

Pinout & Package

Package: PowerSO-20 (HiPSO), thermally enhanced exposed slug, JEDEC MO-166 compliant, R_{th j-case} = 3°C/W - optimized for high-power dissipation in compact automotive PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar automotive LDO with reset applications.

Compared with TLV70750PDPWR and TPS7B6950QDCYRQ1, the L4947PD013TR uniquely delivers full ±80V load dump immunity, external reset delay tuning, and 500mA capability in a thermally efficient PowerSO-20 package - making it the only choice for safety-critical, cranking-resilient automotive power rails.

Availability

L4947PD013TR is available at Aetrix Electronics and suitable for Engine Control Units, Body Control Modules, Instrument Clusters, and Telematics Control Units requiring stable component supply across extended temperature and automotive transient environments.

Supply support for L4947PD013TR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management ICs with vertical manufacturing and AEC-Q100 qualification expertise.

The L4947PD belongs to ST's automotive-grade linear regulator product line, engineered specifically for microprocessor supply in harsh-temperature, high-transient automotive subsystems - prioritizing cranking resilience, integrated protection, and functional safety readiness.

FAQ

What is the minimum input voltage required for regulation at full 500mA load?

The L4947PD013TR maintains regulation down to 6V input at 500mA load, enabled by its 0.75V maximum dropout voltage over –40°C to +125°C. Below 6V, output collapses; this specification is validated per ST's datasheet Figure 1 and absolute maximum ratings table, making it suitable for engine cranking scenarios where battery voltage dips transiently.

Can the reset delay be adjusted to values outside the 10–30ms range specified for 100nF?

Yes - the reset delay T_d scales linearly with external capacitor C_d value. Datasheet test condition shows 10–30ms with 100nF at 25°C; using 47nF yields ~5–14ms, while 220nF extends delay to ~22–66ms. Delay tolerance depends on C_d accuracy and temperature drift, and the internal charging current (20µA typ.) is stable across operating conditions.

Is the L4947PD013TR qualified to AEC-Q100, and what grade does it meet?

Yes - the L4947PD013TR is AEC-Q100 qualified Grade 1 (–40°C to +125°C), as confirmed by STMicroelectronics' official product brief and packaging markings. This qualification covers stress testing for temperature cycling, humidity, ESD, and transient immunity, aligning with automotive electronic control unit reliability requirements.

Does the device require an input capacitor, and if so, what value and type is recommended?

An input capacitor is recommended but not strictly mandatory; ST specifies a 100nF ceramic capacitor between VIN and GND (pin 20 to pins 10/19) close to the device to suppress high-frequency noise and improve transient response. This value is derived from the test circuit in the datasheet (D94AT108) and complements the required 47µF output capacitor for loop stability.