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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - DC DC Switching Regulators

STMicroelectronics E-L6902D

Name: E-L6902D
Brand: STMicroelectronics
SKU: E-L6902D
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: E-L6902D

Manufacturer:: STMicroelectronics

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 8-SOIC (0.154", 3.90mm Width)

Datasheet:: E-L6902D.pdf

Description:: IC REG BUCK ADJ 1A 8SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

L6902D 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 NiCd/NiMH battery chargers and distributed power supplies.

For engineers reviewing the L6902D datasheet, L6902D pinout, L6902D application, or L6902D equivalent, key selection considerations include its adjustable current-limit architecture, SO-8 package thermal performance (R_{th j-amb} = 110 °C/W), internal current-sense inputs (CS+, CS−), feedback disconnection protection, and ±5% output current accuracy under varying load and line conditions.

Technical Context

The L6902D 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. Current sensing uses an on-chip resistor or external sense resistor, enabling accurate current limiting independent of output voltage setting.

It integrates feedforward compensation for improved line transient response, latched overcurrent protection (2.5 A typical trip), thermal shutdown at 150 °C (20 °C hysteresis), and overvoltage/frequency foldback protections. The 250 kHz fixed oscillator enables compact magnetics and stable operation without external timing components.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	8 V to 36 V - supports wide industrial and automotive battery-fed systems without pre-regulation
Output Current	Up to 1 A continuous - sufficient for medium-power battery charging and point-of-load conversion
Reference Voltage	3.3 V ±2% - enables high-accuracy voltage regulation and stable feedback loop design
Current Limit Accuracy	±5% - ensures repeatable charge termination and overload protection across temperature and unit variance
Switching Frequency	250 kHz fixed - allows use of small, low-cost inductors and reduces EMI filtering complexity
Dropout Voltage	0.25 V (typ.) at 1 A - maintains regulation down to low input margins, improving efficiency in wide-V_IN applications
Efficiency	90% at V_OUT = 5 V, V_IN = 12 V - minimizes thermal stress and enables high-density board layout

Pinout & Package

Package: SO-8 (ECOPACK® compliant), surface-mount, 1.27 mm pitch, R_{th j-amb} = 110 °C/W when mounted on standard PCB.

Pin/Terminal	Circuit Role	Design Meaning
1 (OUT)	Power output node	Drives inductor and output capacitor; connects directly to switch node of buck topology
2 (CS+)	High-side current sense input	Accepts voltage from top of external sense resistor or internal sense path; compatible with V_CC-referenced sensing
3 (CS−)	Low-side current sense input	References to GND; enables ground-referenced current sensing with standard shunt placement
4 (COMP)	Error amplifier compensation node	External RC network sets loop bandwidth and phase margin for both voltage and current loops
5 (FB)	Voltage feedback input	1.235 V threshold; resistive divider sets output voltage; direct connection yields fixed 1.235 V output
6 (VREF)	Precision 3.3 V reference output	Stable, no-capacitor-required reference for external circuitry or calibration
7 (GND)	Analog and power ground	Common return for feedback, current sense, and internal bias; requires low-impedance PCB connection
8 (VCC)	Unregulated input supply	Power source for internal logic and gate driver; must be decoupled locally with ≥1 µF ceramic capacitor

Key Features

Feature	Design Value
Integrated P-channel DMOS switch	250 mΩ typical R_DS(on) - eliminates external MOSFET, reduces BOM count and layout area
Adjustable current limit	Programmable via external sense resistor with ±5% accuracy - enables precise battery charge current control
Voltage feedforward	Improves line transient response without additional compensation - stabilizes output during input voltage steps
Feedback disconnection protection	Shuts down output if FB pin is open-circuited - prevents uncontrolled overvoltage in fault conditions
Zero-load operation	Maintains regulation with no output current - supports standby modes in portable and battery-powered systems

Applications

NiCd/NiMH Battery Charger

Distributed Power Supply

Use Scenario: Charging single- or multi-cell NiCd/NiMH batteries in portable medical devices or cordless tools.

IC Role / Device Role / Timing Role: Constant-current/constant-voltage regulator with programmable charge current and automatic termination via current foldback.

Use Value: ±5% current accuracy ensures consistent cell capacity and cycle life; thermal shutdown prevents overheating during prolonged trickle charge.

Use Scenario: Local 5 V or 3.3 V generation from 12–24 V bus in industrial I/O modules or PLC backplanes.

IC Role / Device Role / Timing Role: Step-down DC/DC converter with adjustable current limit for rail protection and fault containment.

Use Value: 250 kHz fixed frequency simplifies EMI filter design; SO-8 package enables high-density power distribution without heatsinks.

Preregulator for Li-ion Systems

Adjustable Current Generator

Use Scenario: Preconditioning 24 V input to ~4.2 V before linear Li-ion charger IC in hybrid power architectures.

IC Role / Device Role / Timing Role: Efficient, current-limited buck stage providing stable intermediate voltage to downstream charging IC.

Use Value: Adjustable current limit (via CS+/CS−) prevents inrush into downstream capacitors; 90% efficiency reduces thermal load on adjacent analog circuits.

Use Scenario: Precision current source for LED biasing, sensor excitation, or calibration reference in test equipment.

IC Role / Device Role / Timing Role: Closed-loop current regulator using CS+ and CS− inputs to maintain set current regardless of load impedance variation.

Use Value: ±5% current accuracy and 1.235 V reference enable sub-1% current setting resolution; zero-load operation supports microamp-level idle states.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
LM5116	Current-mode controller (external MOSFET), 3–75 V input, no integrated switch	Requires external high-side N-MOSFET and gate driver; suited for >3 A designs	Select when higher output current or wider input range is required; not drop-in due to topology and pinout differences
TPS5430	Voltage-mode buck converter, 5.5–36 V input, 3 A output, no dedicated current-sense pins	Fixed internal current limit only; lacks separate CS+/CS− for precision current regulation	Choose for higher-current, non-battery applications where current accuracy is secondary to cost and footprint

Compared with LM5116 and TPS5430, the L6902D uniquely combines integrated P-channel switch, dedicated current-sense inputs, and ±5% current accuracy in SO-8-making it optimal for space-constrained, current-critical battery charging and regulated current sourcing where external component count must be minimized.

Availability

L6902D is available at Aetrix Electronics and suitable for NiCd/NiMH battery chargers, distributed power supplies, and preregulators for lithium-ion systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for L6902D 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 microcontrollers, power ICs, sensors, and analog products for industrial, automotive, and consumer markets.

The L6902D belongs to ST's legacy power management portfolio targeting cost-sensitive, medium-power DC/DC conversion with integrated protection and current regulation-designed specifically for battery charging, portable equipment, and distributed power architectures.

FAQ

What is the maximum allowable input voltage for L6902D?

The absolute maximum input voltage (V_IN) is 40 V per the datasheet's Absolute Maximum Ratings table. Continuous operation above 36 V violates the specified operating input voltage range (8–36 V) and risks premature thermal shutdown or latch-off due to overvoltage stress on internal circuitry and the P-channel DMOS transistor.

Can L6902D operate with no load connected to the output?

Yes. The L6902D supports zero-load operation and maintains regulation even with no output current, enabled by its voltage-mode architecture and internal bias design. This feature is explicitly stated in the datasheet and verified across the full input voltage range (8–36 V) and temperature range (−40 to +125 °C).

How is the current limit adjusted, and what is the accuracy?

The current limit is adjusted using an external sense resistor connected between CS+ and CS−, or via the internal sense path. Accuracy is ±5% over temperature and line conditions, confirmed in Table 5 (Electrical Characteristics) under "IO Operating charging current" and "Il Maximum limiting current" parameters, with test conditions specifying Rsense = 0.1 Ω and V_CC = 8–36 V.

Does L6902D require an external compensation network?

Yes. Compensation is applied at the COMP pin using an external RC network (typically series R and parallel C to GND). The internal transconductance amplifier (g_m = 2.3 mS) and open-loop gain (50–58 dB) require tailored compensation to stabilize both voltage and current control loops-details are provided in Figure 1 (Test and Application Circuit) and Section 4 (Internal Block Diagram).

E-L6902D Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width)

Packaging:: Tube

Product Status:: Obsolete

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 1

Voltage - Input (Min):: 8V

Voltage - Input (Max):: 36V

Voltage - Output (Min/Fixed):: 1.235V

Voltage - Output (Max):: 34V

Current - Output:: 1A

Frequency - Switching:: 250kHz

Synchronous Rectifier:: No

Operating Temperature:: -40°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC

E-L6902D FAQ

1.How can I place an order for E-L6902D through Aetrix?

Please submit a Request for Quotation (RFQ) for E-L6902D on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for E-L6902D reliable?

The price and inventory of E-L6902D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for E-L6902D is usually 5 days.

3.What payment methods are accepted for E-L6902D?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for E-L6902D transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for E-L6902D?

E-L6902D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your E-L6902D order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for E-L6902D?

For technical support, including E-L6902D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your E-L6902D requirements.

6.How does Aetrix verify that E-L6902D is sourced from the original manufacturer or authorized distributors?

All E-L6902D products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that E-L6902D meets industry standards.

7.What is the process for return or replacement of E-L6902D?

All E-L6902D units undergo pre-shipment inspection (PSI). If there is an issue with E-L6902D, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The E-L6902D part is unused and in its original packaging.

Return procedure for E-L6902D:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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