Texas Instruments UCD3138128APFC

Overview

UCD3138128APFC from Texas Instruments is a highly integrated digital power controller for isolated AC/DC and DC/DC converters, featuring 128 kB flash memory, dual-bank firmware update capability, 8 high-resolution DPWM outputs (250 ps pulse width resolution), up to 3 independent PID-based feedback loops, and support for PFC, phase-shifted full-bridge, and LLC topologies in telecom rectifiers and server power supplies.

For engineers reviewing the UCD3138128APFC datasheet, UCD3138128APFC pinout, UCD3138128APFC application, or UCD3138128APFC equivalent, key selection considerations include its 80-pin TQFP package, 31.25 MHz ARM7TDMI-S core, 15-channel 12-bit ADC (539 ksps), synchronous rectifier dead-time optimization peripheral, and dual I²C/PMBus + SPI + dual UART communication interfaces.

Technical Context

The UCD3138128APFC implements three dedicated Digital Power Peripherals (DPPs), each integrating an error ADC (up to 16 MSPS, 1 mV/LSB min), 2-pole/2-zero configurable hardware compensator, and DPWM output with cycle-by-cycle duty matching. Its architecture supports simultaneous voltage, average current, and peak current mode control with automatic FM–PWM and phase-shift–PWM mode switching.

It integrates a 31.25 MHz ARM7TDMI-S processor executing from 128 kB flash (4 × 32 kB banks), 8 kB RAM, and 2 kB ECC-protected data flash; peripherals include 7 analog comparators with programmable blanking, burst-mode and ideal diode emulation for light-load efficiency, and hardware-accelerated current sharing (average/master-slave) for multi-phase systems.

Key Specifications

Pinout & Package

UCD3138128APFC is housed in an 80-pin TQFP package (12.00 mm × 12.00 mm, 0.5 mm pitch) with separate analog/digital ground and power domains (AGND/DGND, V33A/V33D/V33DIO) to minimize noise coupling in high-precision control loops.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital power controller applications.

Compared with UCD3138A64PFC and UCC28950PW, the UCD3138128APFC delivers uniquely scalable firmware, hardware-accelerated control loops, and full PMBus telemetry - making it optimal for programmable, upgradable, and monitored high-density power systems.

Availability

UCD3138128APFC is available at Aetrix Electronics and suitable for telecom rectifiers, server PSU PFC stages, and isolated DC-DC modules requiring stable component supply, long-term lifecycle assurance, and traceable sourcing for industrial and infrastructure programs.

Supply support for UCD3138128APFC 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management technologies, with decades of leadership in digital power control ICs.

The UCD3138 family was designed specifically for high-efficiency, high-density isolated power conversion - targeting telecom, server, and industrial applications needing programmable, reliable, and standards-compliant digital control.

FAQ

What is the primary function of the UCD3138128APFC in a power supply design?

The UCD3138128APFC serves as a fully programmable digital power controller for isolated AC/DC and DC/DC converters. It executes real-time control algorithms for PFC, phase-shifted full-bridge, LLC, and forward topologies using dedicated hardware peripherals - including three PID-based digital power peripherals, 8 high-resolution DPWM outputs, and a 31.25 MHz ARM7TDMI-S core. Its role is to replace analog controllers and discrete logic with a single-chip solution delivering precision regulation, telemetry, and field-upgradable firmware.

Does the UCD3138128APFC support dual-firmware image execution?

Yes, the UCD3138128APFC supports dual-firmware image execution via its 128 kB flash memory partitioned into four 32 kB banks. This architecture allows the device to run firmware from one bank while simultaneously programming a new image into another - enabling seamless field updates without interrupting power delivery. The boot ROM and firmware loader manage bank selection and validation, ensuring safe fallback if the new image fails integrity checks.

How does the synchronous rectifier dead-time optimization peripheral improve efficiency in the UCD3138128APFC?

The UCD3138128APFC includes a dedicated hardware peripheral for synchronous rectifier dead-time optimization that dynamically adjusts gate timing based on real-time current and voltage conditions. This reduces body-diode conduction loss and voltage overshoot during transitions, improving efficiency by up to 1.2% at light loads and lowering MOSFET stress. It eliminates manual dead-time tuning and accelerates development for PSFB and LLC topologies when used with UCD7138 drivers.

What communication interfaces are available on the UCD3138128APFC for system telemetry and configuration?

The UCD3138128APFC provides two I²C/PMBus interfaces (PMBus v1.3 compliant), two UARTs (with auto-baud rate detection), and one SPI interface. These support full telemetry (voltage, current, temperature, faults), real-time configuration, firmware updates, and event logging. The dual I²C/PMBus ports allow concurrent host communication and daisy-chained multi-controller systems, while UART auto-baud simplifies integration with legacy host processors lacking fixed baud-rate clocks.

Can the UCD3138128APFC operate without an external crystal oscillator?

Yes, the UCD3138128APFC can operate using its internal oscillator (240–260 MHz PLL-derived clock), but it also supports an external 10 MHz crystal connected to pins XTAL_IN (61) and XTAL_OUT (62) for improved timing accuracy and stability - especially critical for RTC functions and synchronized multi-device DPWM operation. External crystal use is optional and enabled via configuration bits; the internal oscillator meets all timing specs for standard power control loops.