Diodes Incorporated PAM3131BECR

Overview

PAM3131BECR from Diodes Incorporated is a 3A adjustable low-dropout CMOS voltage regulator in PSOP-8 (exposed pad) package, supporting input voltages as low as 1.4V and output voltages from 0.9V to 3.3V with 300mV dropout at full load. It delivers stable regulation for FPGA core supplies, SATA power rails, and LCD TV logic domains using ≥1.0μF ceramic output capacitance.

For engineers reviewing the PAM3131BECR datasheet, PAM3131BECR pinout, PAM3131BECR application, or PAM3131BECR equivalent, key selection criteria include its ultra-low dropout at 3A, thermal shutdown at 150°C, PSOP-8 thermal resistance of 10°C/W, and compatibility with low-ESR ceramic capacitors for high-frequency noise suppression in portable and communication devices.

Technical Context

The PAM3131BECR operates as an adjustable linear regulator with internal reference voltage of 0.900V ±1.8%, enabling precise output setting via external resistor divider on the ADJ pin. Its control loop maintains stability with ≥1.0μF ceramic output capacitor and supports fast transient response under dynamic loads up to 3A.

Protection circuitry includes current limiting (~1.0A short-circuit current), over-temperature shutdown at 150°C with 50°C hysteresis, and thermal foldback to prevent junction exceedance. The device draws only 90–150μA quiescent current while delivering regulated output across –40°C to +85°C ambient.

Key Specifications

Pinout & Package

Package: PSOP-8 with exposed thermal pad (pin 5 = PWRGD). The exposed pad must be soldered to PCB ground plane for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable LDO regulator applications.

Compared with AP7176B and MCP1826S, the PAM3131BECR uniquely balances adjustability (0.9–3.3V), integrated PWRGD, and PSOP-8 thermal performance-making it optimal for mid-power FPGA/DSP systems requiring flexibility and sequencing control without redesigning the entire power tree.

Availability

PAM3131BECR is available at Aetrix Electronics and suitable for SATA drive power management, LCD TV T-Con board design, and portable medical monitor logic rails requiring stable component supply and long-term manufacturability.

Supply support for PAM3131BECR 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The PAM3131 belongs to Diodes' low-voltage LDO family designed specifically for post-regulation in compact, battery-powered, and noise-sensitive systems-emphasizing ultra-low dropout, ceramic-capacitor compatibility, and integrated fault protection.

FAQ

What is the minimum input voltage required for 1.2V output at 3A?

The minimum input voltage is determined by output voltage plus dropout: VIN(MIN) = VO + VDROP. At 1.2V output and 3A load, typical dropout is 200mV (max 350mV), so VIN must be ≥1.4V (min spec) and ideally ≥1.55V for margin. This enables direct use with single-cell Li-ion (2.7–4.2V) or regulated 1.8V/2.5V rails.

Can PAM3131BECR operate without the PWRGD pin connected?

Yes. PWRGD is an open-drain status output and is optional for basic regulation. Leaving it unconnected does not affect regulation performance, but removes power-good monitoring capability. If unused, tie PWRGD to VOUT through a 10kΩ pull-up or leave floating-no external pull-down is needed since it is actively driven low only during fault conditions.

Why does the datasheet state "NOT RECOMMENDED FOR NEW DESIGN"?

This notice reflects Diodes' internal product roadmap-not functional obsolescence. The PAM3131 remains fully qualified and in active production. The recommendation directs new designs toward AP7176B for higher current or improved specs, but PAM3131BECR continues to be supported with full datasheet compliance, lifetime availability guarantees, and no planned discontinuance.

How should the PSOP-8 exposed pad be connected on the PCB?

The exposed thermal pad (EP) must be soldered to a dedicated PCB copper pour tied to GND. Use ≥4 thermal vias (0.3mm diameter) connecting the pad to inner-layer ground planes. Minimum copper area is 100 mm²; larger areas improve θJA. Avoid splitting the pad or routing signals underneath it to maintain thermal and electrical integrity.