ST L6902 Up to 1 A Switching Regulator with Adjustable Current Limit
Summary
The L6902 is a compact, high-efficiency DC/DC switching regulator providing constant voltage and adjustable current limit control (up to 1A). Ideal for engineers developing reliable power supplies for battery systems, portable devices, or mobile PC applications requiring enhanced protection features. This manual offers comprehensive technical documentation, including detailed electrical characteristics, operational ratings, precise pin assignments, and advanced system protections like thermal shutdown and overvoltage safeguards, guiding you through successful implementation of your next project.
Page 1 Text Content
Up to 1 A switching regulator with adjustable current limit
Features Up to 1 A output current Operating input voltage from 8 V to 36 V Precise 3.3 V (±2%) reference voltage 5 % output current accuracy Output voltage adjustable from 1.235 V to 34 V
250 k Hz internally fixed frequency
current control can be used to charge Ni MH and
Voltage feedforward
Ni Cd batteries.
Zero load current operation
The device can be used as a standard DC/DC
Adjustable current limit
converter with adjustable current limit (set by
Protection against feedback Disconnection using the external sense resistor). Thermal shutdown
The internal robust P-channel DMOS transistor with a typical of 250 mΩ assures high efficiency Applications and a minimum dropout even at high output current level. The internal limiting current (latched
Chargers for Ni Cd, Ni MH batteries and function) of typical value of 2.5 A protects the preregulator for lithium-ion batteries device from accidental output short circuit
avoiding dangerous loads damage.
Adjustable current generator
Simple step-down converters with adjustable If the temperature of the chip goes higher than a current limit fixed internal threshold (150°C with 20°C hysteresis), the power stage is turned off.
Battery equipped systems
Other protections beside thermal shutdown
Distributed power supply
complete the device for a safe and reliable
Mobile PC and subnotebook
application: overvoltage protection, frequency folback overcurrent protection and protection vs.
Description feedback disconnection.
The L6902D is a complete and simple step down The internal fixed switching frequency of 250KHz, switching regulator with adjustable current limit. and the SO-8 package pin allow to built an ultra compact DC/ DC converter with a minimum board
Based on a voltage mode structure it integrates a
space.
current error amplifier to have a constant voltage and constant current control.
Table 1. Device summary
By means of an on board current sense resistor
Order codes Package Packaging
and the availability of the current sense pins (both compatible to Vcc and for Cs- compatible with
L6902D Tube
GND too) a current limit programming is very SO-8
L6902D013TR Tape and reel
simple and accurate (±5%). Moreover constant
November 2010 Doc ID 7332 Rev 9 1/11
www.st.com
Page Summary Contents For ST L6902 Up to 1 A Switching Regulator with Adjustable Current Limit
Manual Details
| Brand | Current |
|---|---|
| Pages | 11 |
| File Size | 197.56 KB |
| Published | May 28, 2026 |
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Frequently Asked Questions
What voltage levels are required to set the output voltage?
An external resistive divider using R1 and R2 connected to pin 4 is needed for precise voltage adjustments higher than the default 1.235 V.
What specific safety mechanisms prevent component damage?
Protections include thermal shutdown, overvoltage protection, and overcurrent protection against accidental output short circuit.
Does the L6902 support battery charging applications?
Yes, it can charge NiCd and NiMH batteries using constant current control features.
What is the operational input voltage range for this converter?
The device operates with an input voltage ranging from 8 V up to 36 V.