STMicroelectronics L5956PD

Overview

L5956PD from STMicroelectronics is a multifunction automotive voltage regulator IC integrating four independent LDO regulators (8.5 V/500 mA, 5 V/300 mA permanent, 5 V/800 mA, 3.3 V/800 mA) and a 2 A high-side power switch, with ignition monitoring, reset generation, load dump protection, and thermal shutdown - designed for car radio power management systems.

For engineers reviewing the L5956PD datasheet, L5956PD pinout, L5956PD application, or L5956PD equivalent, this device supports multi-rail sequencing in infotainment head units, provides integrated fault detection for battery-supplied 12 V systems, and delivers low-quiescent-current standby operation (<100 µA) critical for always-on automotive modules.

Technical Context

The L5956PD implements a triple-LDO + single-LDO architecture with separate input rails (Vin1 for REG1 and standby REG2; Vin2 for REG3 and REG4), enabling flexible supply partitioning in automotive audio systems. Its ignition comparator monitors battery voltage thresholds (9.5 V low, 20 V high) with hysteresis to trigger hold signals during cranking or overvoltage events.

The integrated 2 A high-side driver features programmable delay protection (15–40 ms), peak current limiting (2–3.5 A for <15 ms), and short-circuit foldback. Reset functionality uses a push-pull buffer with 4.7 V nominal threshold, 100 mV hysteresis, and 47 nF capacitor-programmable delay (10–60 ms).

Key Specifications

Pinout & Package

Package: PowerSO20 (slug-up), thermally enhanced surface-mount package with exposed die attach pad on top side for direct PCB copper thermal coupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multifunction automotive regulator applications.

Compared with TLE4271-2G and UC2843BD1R2G, the L5956PD uniquely integrates four LDOs + high-side switch + ignition/reset/hold functions in one PowerSO20 package - reducing bill-of-materials by ≥12 components and eliminating external sequencing logic required by alternatives.

Availability

L5956PD is available at Aetrix Electronics and suitable for automotive infotainment head units, car radio power management systems, and telematics control units requiring stable component supply across extended temperature (-40°C to +85°C) and high-reliability automotive qualification.

Supply support for L5956PD 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, designing and manufacturing silicon solutions for automotive, industrial, and consumer markets since 1987.

The L5956PD belongs to ST's automotive power management IC portfolio, engineered specifically for cost-sensitive, space-constrained car radio and infotainment applications requiring integrated voltage regulation, protection, and system supervision.

FAQ

What is the maximum allowable junction temperature for continuous operation of the L5956PD?

The L5956PD has an absolute maximum junction temperature of 150°C, with thermal shutdown activating above this threshold. Its PowerSO20 package offers 1.5°C/W junction-to-case thermal resistance, enabling 43 W power dissipation at 85°C case temperature - sufficient for full-load operation in properly heatsinked automotive head unit PCBs.

Can the L5956PD's 5 V standby regulator (REG2) be used to power an external microcontroller's RTC domain?

Yes - REG2 delivers 5 V ±250 mV at up to 300 mA continuously with quiescent current ≤100 µA over -20°C to +85°C. Its permanent enable state (no external EN required) and low dropout (0.6 V at 100 mA) make it ideal for RTC, backup RAM, and CAN wake-up circuitry in always-on automotive modules.

How does the ignition comparator function differ from standard voltage monitoring in the L5956PD?

The L5956PD's ignition comparator uses a Schmitt-trigger input (1.18 V rising / 1.03 V falling) with programmable hysteresis to detect engine cranking (VIN1 dip below 9.5 V) and alternator overvoltage (VIN1 surge above 20 V). It asserts HOLD to signal safe-state entry - unlike basic monitors, it provides noise-immune, bounce-free transitions critical for reliable start-stop operation.

Is external compensation required for stability of the L5956PD's LDO outputs?

No - all four regulators are internally compensated and stable with 10 µF to 47 µF ceramic output capacitors (ESR 7–74 mΩ). Figure 4 in the datasheet specifies maximum ESR limits per regulator, and typical application circuits (Figure 3) confirm stability without additional RC networks - simplifying layout and reducing component count.