Texas Instruments LM5002MA

Overview

LM5002MA from Texas Instruments is a high-voltage current-mode PWM controller with integrated 75-V/0.5-A N-channel MOSFET, designed for boost, flyback, SEPIC, and forward DC-DC converters. It operates from 3.1 V to 75 V input, delivers 1.26-V ±1.5% reference accuracy, supports up to 1.5 MHz switching, and includes thermal shutdown, UVLO, and oscillator synchronization - enabling compact industrial power supplies.

For engineers reviewing the LM5002MA datasheet, LM5002MA pinout, LM5002MA application, or LM5002MA equivalent, key selection criteria include input voltage range (3.1–75 V), integrated MOSFET R_DS(on) (850–1600 mΩ), COMP pin loop compensation interface, EN/UVLO dual-threshold control, and SOIC-8 package thermal resistance (R_θJA = 105.7°C/W).

Technical Context

The LM5002MA implements peak current-mode control with internal slope compensation (450-mV ramp) to prevent subharmonic oscillation above 50% duty cycle. Its PWM comparator compares a scaled current-sense signal (2.1 V/A) plus slope ramp against the COMP pin voltage, while cycle-by-cycle limiting triggers at 0.5 A (±200 ns delay).

It integrates a wide-input LDO bias regulator (3.1–75 V → regulated 6.9 V on VCC), supports external VCC supply (7–12 V) to bypass internal regulation, and features dual-level EN control (0.45 V shutdown / 1.26 V enable) with 100-mV hysteresis per threshold.

Key Specifications

Pinout & Package

LM5002MA is supplied in an 8-pin SOIC (D) package (4.90 mm × 3.90 mm), with exposed pad not present. Pin functions are validated per TI SNVS496F Rev F (May 2021).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage PWM controller applications.

Compared with LM5122MH/NOPB, LM5002MA trades external FET flexibility for smaller footprint and lower component count in sub-5 W converters; versus UCC28C42DR, it adds critical high-voltage operation, integrated current sense, and slope compensation for stable wide-input designs.

Availability

LM5002MA is available at Aetrix Electronics and suitable for industrial power supplies, automotive DC-DC converters, telecom line cards, and test equipment power modules requiring stable component supply across extended temperature and voltage ranges.

Supply support for LM5002MA 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The LM5002MA belongs to TI's high-voltage DC-DC controller product line, engineered specifically for efficient, compact non-isolated and isolated power conversion in harsh-input environments - emphasizing integration, transient robustness, and design simplicity.

FAQ

What is the absolute maximum input voltage rating for the LM5002MA?

The LM5002MA has an absolute maximum VIN-to-GND rating of 76 V. Operation beyond this voltage risks permanent damage. The recommended operating range is 3.1 V to 75 V. Transient ringing on the VIN line - especially during load dump or hot-swap events - must be clamped or filtered to ensure peak voltage stays below 76 V. Layout best practices include placing high-quality ceramic capacitors directly at the VIN and GND pins.

How does the LM5002MA implement current limiting and what is its typical threshold?

The LM5002MA uses internal peak current-mode control with a dedicated current-sense amplifier and comparator. Its typical cycle-by-cycle current limit threshold is 0.5 A, corresponding to a 1.5-V comparator trip point derived from a 100-mΩ internal sense resistor amplified 30×. The current limit delay is 100–200 ns, ensuring fast response to overloads. This feature also enables controlled soft-start by gradually increasing COMP voltage during startup.

Can the LM5002MA operate without an external RT resistor when synchronized to an external clock?

No, the LM5002MA requires an external RT resistor connected between the RT pin and GND even when externally synchronized. The resistor sets the internal oscillator's free-running frequency baseline and provides DC bias for the sync pulse coupling network. A 100-pF capacitor couples the external clock into the RT pin, but the RT resistor remains mandatory to maintain proper DC operating point and ensure reliable synchronization detection above 2.6 V peak.

What is the function of the COMP pin on the LM5002MA and how is it used in loop compensation?

The COMP pin on the LM5002MA is the open-drain output of the internal error amplifier. It serves as the control node for the feedback loop: a Type-II compensation network (typically two resistors and one capacitor) is connected between COMP and FB pins to stabilize the converter. The internal 5-kΩ pullup enables opto-coupler interfacing in isolated designs. COMP voltage directly modulates PWM duty cycle - higher COMP increases on-time until current limit or oscillator reset occurs.

Does the LM5002MA support external biasing of the VCC pin, and what are the voltage limits?

Yes, the LM5002MA supports external biasing of the VCC pin to improve efficiency in high-input-voltage applications. An external 7 V to 12 V supply can be applied to VCC, which disables the internal LDO regulator and reduces power dissipation. The externally applied VCC voltage must never exceed 14 V or surpass the VIN voltage - doing so forward-biases the internal VCC-to-VIN body diode and may damage the device. A 0.47-µF ceramic capacitor remains required at the VCC pin regardless of bias source.