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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > LED Drivers

STMicroelectronics STLD20D-DEF

Name: STLD20D-DEF
Brand: STMicroelectronics
SKU: STLD20D-DEF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: STLD20D-DEF

Manufacturer:: STMicroelectronics

Category:: LED Drivers

Package:: 8-VQFN

Datasheet:: STLD20D-DEF.pdf

Description:: IC LED DRVR RGLTR PWM 21MA 8QFN

Quantity:: RFQ Add To RFQ list

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Inventory:3,232

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Product details

Overview

STLD20D-DEF from STMicroelectronics is a constant-frequency PWM boost LED driver IC designed to supply up to 4 white LEDs in series from 2.8V–4.2V battery sources. It delivers 20mA regulated LED current with 80–85% efficiency, integrates a load disconnect switch (R_DS(on) = 4.3Ω @ 4.2V), and features overvoltage (18.5V) and overtemperature (110°C) protection with automatic restart - used in mobile phone LCD backlight systems.

For engineers reviewing the STLD20D-DEF datasheet, STLD20D-DEF pinout, STLD20D-DEF application, or STLD20D-DEF equivalent, key selection criteria include its QFN 3×3 8L package, 500kHz switching frequency, shutdown-controlled PWM dimming up to 10kHz, and FB pin reference voltage of 0.302V for precise current regulation via external R_LED.

Technical Context

The STLD20D-DEF implements a fixed-frequency (400–600kHz) PWM-controlled boost converter with internal compensation to reject input voltage transients. Its feedback loop regulates LED current by sensing voltage across an external R_LED (15Ω typical), referenced to a 0.302V internal error amplifier threshold.

It integrates dual protection circuitry: overvoltage protection triggers at 18.5V on VOUT with 0.7V hysteresis, and overtemperature protection disables operation above 110°C with 5°C hysteresis. The LDS switch isolates the LED string in shutdown, reducing leakage to <1µA.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	2.8V to 4.2V - matches Li-ion battery discharge profile without external regulation.
LED Current Accuracy	19–21mA @ R_LED = 15Ω - ensures consistent brightness across temperature and supply variation.
Switching Frequency	400–600kHz - enables use of small 10µH shielded inductors and 1µF ceramic output capacitors.
FB Reference Voltage	0.285–0.315V - sets LED current as I_LED = V_FB/R_LED, enabling precise analog or PWM dimming.
LDS R_DS(on)	4.2–4.3Ω @ 4.2V - minimizes dropout loss during active drive while enabling full LED string isolation in shutdown.
OVP Threshold	17.5–20V - protects against open-circuit LED failure by disabling SW before VOUT exceeds 20V.
Shutdown Current	<1µA - eliminates standby power drain in portable devices during sleep mode.

Pinout & Package

STLD20D-DEF uses a thermally enhanced QFN 3×3 mm, 8-lead package with exposed thermal pad (pin 9). Pin 1 is marked by a dot; top-view pin order is SW, VIN, SHDN, RSET, FB, LDS, VOUT, GND (clockwise from top-left).

Pin/Terminal	Circuit Role	Design Meaning
SW	Boost switch drain node	Connects to inductor and diode anode; switches at 500kHz with R_DS(on) = 0.42Ω @ 4.2V.
VIN	Main power input	Accepts 2.8–4.2V battery input; powers internal circuitry and boost stage.
SHDN	Digital enable/disable control	Active-low logic input; drives controller into ultra-low-I_Q state (<1µA) and activates LDS switch.
RSET	Peak current programming (NC on -DEF)	No-connect on STLD20D-DEF; fixed 640mA peak limit (unlike -C8 variant which supports resistor-programmable ILIM).
FB	Current sense feedback	Monitors voltage across R_LED; closed-loop regulation maintains I_LED = V_FB/R_LED.
LDS	Load disconnect switch source	Connects to LED cathode; opens path in shutdown to eliminate DC leakage through LEDs.
VOUT	Boost output node	Drives LED anodes; OVP circuit monitors this pin to detect open-string fault conditions.
GND	Analog/digital ground	Common return for FB, SHDN, and LDS; must be low-impedance connection to exposed thermal pad.

Key Features

Feature	Design Value
Integrated Load Disconnect Switch	Eliminates LED string leakage current in shutdown, enabling true zero-current off-state for battery-sensitive designs.
Supply Voltage Rejection	0.9mA/V line regulation - suppresses display flicker during battery voltage sag by maintaining stable LED current.
PWM Dimming Support	Full-brightness ON/OFF switching up to 10kHz - preserves LED color point and avoids analog dimming nonlinearity.
Thermal Shutdown with Hysteresis	110°C trip / 105°C recovery - prevents thermal runaway while allowing automatic recovery after cooling.
Small External Component Count	Requires only 10µH inductor, 1µF ceramic C_OUT, 15Ω R_LED, and Schottky diode - reduces PCB area and BOM cost.

Applications

Mobile Phone Backlight

Portable Media Player Display

Use Scenario: Powering 4-series white LEDs in a slim smartphone LCD module powered by single-cell Li-ion battery.

IC Role / Device Role / Timing Role: Constant-current boost regulator with integrated LDS switch and OVP, operating at 500kHz to minimize EMI and filter size.

Use Value: Enables flicker-free backlighting across full battery range (4.2V → 2.8V) while consuming <1µA in sleep mode.

Use Scenario: Driving edge-lit LED array in MP3 player's 2.8-inch TFT display under variable ambient temperature.

IC Role / Device Role / Timing Role: LED current controller with supply rejection and thermal protection, ensuring stable luminance from –40°C to +85°C.

Use Value: Maintains ±1mA LED current accuracy despite input voltage and temperature drift, preserving display uniformity.

PDA Organizers

Handheld Gaming Devices

Use Scenario: Compact backlight solution for monochrome or color LCD in legacy PDA with tight board space constraints.

IC Role / Device Role / Timing Role: High-efficiency (85% @ 4.2V) boost driver with QFN 3×3mm footprint and no external compensation components.

Use Value: Reduces total solution size by 40% vs. SOT23-8 alternatives while delivering identical 20mA output performance.

Use Scenario: Brightness-controlled LED backlight in battery-powered handheld console requiring silent, ripple-free dimming.

IC Role / Device Role / Timing Role: PWM-dimmable LED driver supporting 10kHz digital control without audible noise or color shift.

Use Value: Delivers smooth brightness scaling from 1% to 100% using standard MCU GPIO, eliminating need for DAC or external PWM generator.

Equivalent & Alternatives

The following parts are listed as comparable options for similar white LED boost driver applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MAX1910	Fixed 1.2MHz switching frequency; no integrated LDS switch; requires external MOSFET for LED disconnection.	Lacks true zero-current shutdown - residual LED leakage persists unless external FET added.	Choose when higher switching frequency justifies added complexity and board area for smaller magnetics.
TPS61160	Adjustable switching frequency (600kHz–1.2MHz); 30V OVP; no thermal shutdown; higher quiescent current (25µA).	Higher OVP threshold suits 6–8 LED strings but lacks OTP - requires external thermal monitoring in high-power layouts.	Prefer for multi-LED configurations where extended output voltage range outweighs missing thermal protection.

Compared with MAX1910 and TPS61160, STLD20D-DEF uniquely integrates load disconnect and thermal protection in a QFN 3×3mm package while maintaining sub-1µA shutdown current - critical for long battery life in compact portable devices.

Availability

STLD20D-DEF is available at Aetrix Electronics and suitable for mobile phone backlight, portable media player display, and PDA organizer applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for STLD20D-DEF 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 management ICs, and analog/mixed-signal devices for automotive, industrial, and consumer markets.

The STLD20D product line targets portable backlighting applications, delivering highly integrated, battery-optimized LED drivers with minimal external components and robust protection features.

FAQ

What is the function of the RSET pin on STLD20D-DEF?

The RSET pin is not connected internally on the STLD20D-DEF variant. Unlike the STLD20D-C8, which uses an external resistor to program peak inductor current (ILIM), the -DEF version has a fixed 640mA ILIM threshold. Leaving RSET unconnected or floating is required per datasheet layout guidance.

Can STLD20D-DEF drive more than 4 white LEDs?

No - STLD20D-DEF is characterized and guaranteed for up to 4 white LEDs in series (max ~16V VOUT). Attempting to drive 5+ LEDs risks exceeding its 20V absolute maximum VOUT rating and triggering OVP shutdown. For higher LED counts, select a driver rated for ≥24V output like the STLD40.

How does the LDS switch improve system efficiency?

The integrated Load Disconnect Switch (LDS) opens the LED current path during shutdown, eliminating the DC leakage path present in conventional boost drivers. This reduces total system standby current to <1µA - extending battery life in always-on portable devices by preventing continuous LED string discharge.

Is STLD20D-DEF still in active production?

STLD20D-DEF is marked as obsolete by STMicroelectronics per official documentation, but Aetrix Electronics maintains legacy inventory with full traceability and offers engineering support for design-in continuity, including pin-compatible alternatives and migration paths for new designs.

STLD20D-DEF Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: 8-VQFN

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Type:: DC DC Regulator

Topology:: Step-Up (Boost)

Internal Switch(s):: Yes

Number of Outputs:: 1

Voltage - Supply (Min):: 2.8V

Voltage - Supply (Max):: 4.2V

Voltage - Output:: -

Current - Output / Channel:: 21mA

Frequency:: 500kHz

Dimming:: Analog, PWM

Applications:: Backlight

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-QFN (3x3)

STLD20D-DEF FAQ

1.How can I place an order for STLD20D-DEF through Aetrix?

Please submit a Request for Quotation (RFQ) for STLD20D-DEF 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 STLD20D-DEF reliable?

The price and inventory of STLD20D-DEF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STLD20D-DEF is usually 5 days.

3.What payment methods are accepted for STLD20D-DEF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STLD20D-DEF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STLD20D-DEF?

STLD20D-DEF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STLD20D-DEF 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 STLD20D-DEF?

For technical support, including STLD20D-DEF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STLD20D-DEF requirements.

6.How does Aetrix verify that STLD20D-DEF is sourced from the original manufacturer or authorized distributors?

All STLD20D-DEF 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 STLD20D-DEF meets industry standards.

7.What is the process for return or replacement of STLD20D-DEF?

All STLD20D-DEF units undergo pre-shipment inspection (PSI). If there is an issue with STLD20D-DEF, 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 STLD20D-DEF part is unused and in its original packaging.

Return procedure for STLD20D-DEF:

1.Submit a request within 90 days.

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

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