STMicroelectronics L6902D013TR

Overview

L6902D013TR from STMicroelectronics is a voltage-mode step-down switching regulator with integrated P-channel DMOS transistor (250 mΩ typical R_DS(on)), adjustable current limit (±5% accuracy), and 1 A continuous output current capability. It operates from 8 V to 36 V input, delivers adjustable output voltage from 1.235 V to 34 V, and features precise 3.3 V ±2% reference, 250 kHz fixed switching frequency, and zero-load operation - used in NiMH/NiCd battery chargers and distributed power supplies.

For engineers reviewing the L6902D013TR datasheet, L6902D013TR pinout, L6902D013TR application, or L6902D013TR equivalent, key selection criteria include its adjustable current-limit architecture, internal current-sense inputs (CS+/CS−), thermal shutdown (150°C with 20°C hysteresis), overvoltage protection, and SO-8 package compatibility for compact DC/DC designs.

Technical Context

The L6902D013TR implements a voltage-mode control architecture with dual error amplifiers: one for voltage regulation (FB input, 1.235 V reference) and one for constant-current control via dedicated CS+ and CS− terminals. Its internal 250 kHz oscillator enables predictable EMI behavior and supports small external passive components.

Voltage feedforward compensation improves line regulation across the 8–36 V input range, while the latch-type current limit (2.5 A typical) and feedback disconnection protection ensure robust fault handling without external circuitry - critical for battery charging and unregulated input environments.

Key Specifications

Pinout & Package

Supplied in SO-8 package (ECOPACK® compliant), the L6902D013TR uses standard 150 mil body width with gull-wing leads and thermal pad-compatible footprint per ST's mechanical drawing (Doc ID 7332 Rev 9, Table 1).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down regulator with adjustable current limit applications.

Compared with LM5116PWPR and TPS5430DDAR, the L6902D013TR uniquely integrates both voltage and current error amplifiers with dedicated CS+/CS− inputs, enabling true dual-loop CV/CC operation in a single SO-8 package - ideal for battery charging and precision current sourcing where accuracy and integration outweigh raw power scalability.

Availability

L6902D013TR is available at Aetrix Electronics and suitable for NiCd/NiMH battery chargers, distributed power supplies, and mobile PC subnotebook power systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for L6902D013TR 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 analog, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The L6902 series belongs to ST's legacy power management portfolio targeting simple, robust DC/DC conversion in cost- and space-constrained applications - emphasizing integration, protection, and ease of use over digital configurability.

FAQ

What is the maximum safe operating junction temperature for L6902D013TR?

The L6902D013TR features thermal shutdown triggered at 150°C junction temperature with 20°C hysteresis, meaning the device resumes operation only after cooling to ≤130°C. Its maximum rated junction temperature is 150°C, and thermal resistance junction-to-ambient is 110°C/W when mounted on a standard PCB - proper copper pour and airflow are essential to sustain 1 A output continuously.

Can L6902D013TR operate with an output voltage lower than 1.235 V?

No - the internal reference sets the minimum regulated output at 1.235 V, as defined by the FB pin threshold. Output voltages below this value cannot be stabilized in regulation mode. For sub-1.2 V rails, an external reference or different topology (e.g., LDO or controller with adjustable reference) is required.

How is the current limit programmed, and what is the role of CS+ and CS−?

The current limit is set by an external sense resistor between OUT and the load. CS+ monitors the high-side (OUT-side) voltage of the resistor; CS− monitors the low-side (load-side) voltage. The internal current error amplifier compares their difference to a 100 mV threshold, enabling ±5% accurate current limiting without external op-amps or comparators.

Does L6902D013TR require an external bootstrap capacitor?

No - the L6902D013TR uses a P-channel high-side MOSFET, eliminating the need for a bootstrap capacitor. This simplifies layout and improves reliability in high-duty-cycle or low-input-voltage conditions where bootstrap charging may fail in N-channel-based controllers.