STMicroelectronics L4938NPD013TR

Overview

L4938NPD013TR from STMicroelectronics is a dual low-dropout voltage regulator IC designed for automotive microcomputer power supply systems. It delivers a precision 5V ±2% standby output (VO1, 50mA) and a tracked/adjustable main output (VO2, up to 500mA), with integrated power-on reset, undervoltage warning, enable control, and thermal/short-circuit protection. Its 40V transient tolerance and <250µA standby quiescent current support engine control units and body electronics.

For engineers reviewing the L4938NPD013TR datasheet, L4938NPD013TR pinout, L4938NPD013TR application, or L4938NPD013TR equivalent, key selection criteria include VO2 tracking accuracy (±25mV), dropout performance (0.25V/0.6V max), reset delay programmability via CT capacitor, and PowerSO-20 package thermal resistance (9°C/W junction-to-case).

Technical Context

The device integrates two independent LDO regulators: VO1 uses an isolated-collector vertical PNP for ultra-low dropout (down to 2V input) and stable 5V regulation; VO2 employs the same topology but supports higher current and adjustable output (5–20V) via external resistor divider on ADJ pin. Both outputs share ground-referenced sensing and protection circuitry.

Its auxiliary functions are tightly coupled to system supervision: the RESET block monitors VO1 with 4.7V threshold and user-defined delay (tRD = CT × 2V / 2µA); the SENSE comparator (1.23V reference) provides early undervoltage warning via SI/SO pins. Enable logic disables VO2 while preserving VO1 in standby mode.

Key Specifications

Pinout & Package

Package: PowerSO-20 (PSO20), thermally enhanced surface-mount package with exposed slug; R_thj-case = 9°C/W, R_thj-amb < 20°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-LDO automotive regulator applications.

Compared with TLE4275G and TPS7B8133QPWPRQ1, L4938NPD013TR uniquely integrates dual LDOs with tracking, programmable VO2, reset delay tuning, and early warning sense-making it irreplaceable for automotive systems requiring coordinated multi-rail power sequencing and fault monitoring.

Availability

L4938NPD013TR is available at Aetrix Electronics and suitable for engine control units, body control modules, ADAS camera ECUs, and infotainment head units requiring stable component supply across extended automotive temperature and lifetime requirements.

Supply support for L4938NPD013TR 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 broad AEC-Q100 qualification coverage.

The L4938 series belongs to ST's automotive power management portfolio, engineered specifically for microcomputer-controlled vehicle systems needing robust dual-rail regulation, fault supervision, and transient resilience.

FAQ

What is the maximum allowable value for the CT capacitor used in the reset delay circuit?

The CT capacitor value is not strictly capped by the datasheet, but practical limits arise from leakage and board space. For reliable 100µs delay, 100nF is typical; values above 1µF increase tRD linearly but risk excessive discharge time and reduced noise immunity. ST recommends CT ≤ 1µF to maintain tRR < 50µs and ensure fast reset reaction.

Can the L4938NPD013TR be used with VO2 set to 3.3V?

Yes-VO2 can be set from 5V to 20V using the ADJ pin and external resistor divider. To achieve 3.3V, connect VO1 (5V) to ADJ via a resistive divider that scales 5V down to 1.23V at ADJ. However, this violates the minimum VO2 specification (5V); output regulation and stability are not guaranteed below 5V per datasheet limits.

How does the SENSE comparator behave when SI is left unconnected?

Leaving SI floating is not recommended. The SI pin has internal ESD protection but no pull-up/down; floating input may cause erratic SO output or increased quiescent current. If unused, SI must be tied to GND per datasheet guidance, increasing standby IQ from 290µA to 300µA-still within the <250µA spec at TJ < 100°C and VS = 14V.

Is the PowerSO-20 package RoHS-compliant and lead-free?

Yes-the L4938NPD013TR uses STMicroelectronics' standard PowerSO-20 package, which is RoHS-compliant and lead-free per EU Directive 2011/65/EU and JEDEC J-STD-020. The exposed slug is matte tin-plated, and all solder-reflow profiles meet IPC/JEDEC J-STD-020D moisture sensitivity level 3 requirements.