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STMicroelectronics STLD40DPMR
- Part No.:
- STLD40DPMR
- Manufacturer:
- STMicroelectronics
- Category:
- LED Drivers
- Package:
- 8-VDFN Exposed Pad
- Datasheet:
-
STLD40DPMR.pdf
- Description:
- IC LED DRVR RGLTR PWM 20MA 8QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,933
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Product details
Overview
STLD40DPMR from STMicroelectronics is a PFM-mode inductor-switch boost controller IC designed to drive up to 10 white LEDs in series for LCD backlighting. It operates from 3.0 V to 5.5 V input, delivers up to 37 V output, regulates 20 mA LED current, and features adjustable peak inductor current limit (0.2–1 A), OVP with 1.5 V hysteresis, and PWM dimming via EN pin.
For engineers reviewing the STLD40DPMR datasheet, STLD40DPMR pinout, STLD40DPMR application, or STLD40DPMR equivalent, key selection criteria include its QFN8 3×3 mm footprint, 250 ns minimum OFF time, 5.5 µs maximum ON time, 75–80% efficiency across input range, and integrated OVP restart behavior.
Technical Context
The STLD40DPMR implements a discontinuous conduction mode (DCM) PFM boost architecture where regulation is achieved by sensing LED current through an external RLED resistor and comparing FB voltage (130–200 mV) against an internal reference. The embedded N-channel MOSFET switch has RDSON ≤ 0.5 Ω and BVDS ≥ 38 V.
Peak inductor current is programmable via RSET (12–100 kΩ), setting limits from 0.2 A to 1 A; OVP triggers at 36–42 V with automatic restart after 1.5 V hysteresis; EN pin accepts logic-high enable (VIH ≥ 1.2 V) and supports low-frequency PWM dimming without external circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.0 V to 5.5 V - supports single-cell Li-ion, Li-polymer, or triple-AA battery operation |
| Output Voltage Range | Up to 37 V - sufficient to bias 10-series white LEDs (VF ≈ 3.2–3.7 V each) |
| Regulated LED Current | 20 mA - stable current delivery for uniform brightness across full LED string |
| Efficiency | 75% at 3.0 V / 80% at 5.5 V (IO = 20 mA, VO = 36 V) - minimizes thermal load in space-constrained handhelds |
| OVP Threshold | 36–42 V with 1.5 V hysteresis - prevents overvoltage damage during open-circuit or feedback loss |
| Shutdown Current | < 1 µA - enables ultra-low-power standby in battery-powered devices |
| Peak Inductor Current Limit | 0.2 A to 1 A (set by RSET) - allows optimization of inductor size and transient response |
Pinout & Package
STLD40DPMR is housed in a thermally enhanced QFN8 package (3 mm × 3 mm, 0.9 mm height) with exposed thermal pad (PGND-connected) and wettable flanks for automated optical inspection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VI | Power input supply | Accepts 3.0–5.5 V DC; requires local 2.2 µF ceramic decoupling |
| 2 RSET | Peak current programming | Connects to GND via resistor (12–100 kΩ) to set inductor current limit |
| 3 GND | Analog ground reference | Separate from PGND; must be star-connected near FB and RLED |
| 4 FB | Current-sense feedback | Senses voltage across RLED (8 Ω typical); regulates LED current to 20 mA |
| 5 N.C. | No connection | Internally unconnected; must remain floating or grounded per layout guidelines |
| 6 VO | Boost output node | Drives LED anode string; connects to Schottky diode cathode (e.g., STPS1L40M) |
| 7 EN | Enable/dimming control | Logic-high (≥1.2 V) enables operation; PWM signal here controls LED brightness |
| 8 SW | Switch node | Drain of internal MOSFET; connects to inductor and Schottky diode anode |
Key Features
| Feature | Design Value |
|---|---|
| PFM control with DCM operation | Enables high efficiency at light loads and eliminates audible switching noise in portable displays |
| Integrated OVP with auto-restart | Protects LEDs and external components during feedback fault without requiring external latch circuitry |
| Adjustable peak current limit | Allows precise inductor sizing and EMI optimization while maintaining safe SOA under all input conditions |
| Low shutdown current & PWM dimming | Extends battery life in standby and enables flicker-free brightness control using standard MCU GPIO |
| QFN8 3×3 mm with thermal pad | Provides 52 °C/W junction-to-ambient thermal resistance for reliable operation at 20 mA continuous load |
Applications
| LCD Backlight for Smartphones | Handheld PDA Display Power |
|---|---|
Use Scenario: Driving 8–10 white LEDs in series for 3.5–4.3 inch smartphone LCD panels powered by single-cell Li-ion battery. IC Role / Device Role / Timing Role: Boost controller regulating constant LED current; PFM modulation adapts switching frequency dynamically to maintain efficiency across battery discharge curve. Use Value: Delivers 20 mA at 32–36 V output with >75% efficiency at 3.0 V input, minimizing heat generation in thin form factor. | Use Scenario: Powering monochrome or color TFT display in legacy PDAs and enterprise organizers operating from 3.3 V or dual-AA supply. IC Role / Device Role / Timing Role: Primary LED driver IC enabling compact, low-component-count backlight solution with no external gate driver or compensation network. Use Value: Integrates OVP, current sense, and enable logic-reducing BOM count by 4 discrete parts versus discrete boost + comparator approach. |
| Portable Medical Device Displays | Industrial Handheld Terminal Backlight |
Use Scenario: Illuminating critical status displays in battery-operated medical monitors and diagnostic tools requiring consistent brightness and long runtime. IC Role / Device Role / Timing Role: Constant-current LED driver with fail-safe OVP and <1 µA shutdown current for emergency power preservation. Use Value: Maintains regulated 20 mA output despite input sag to 3.0 V, ensuring display visibility during low-battery alerts. | Use Scenario: Backlighting ruggedized LCDs in warehouse scanners, field service terminals, and logistics handhelds exposed to wide temperature (-40°C to +85°C). IC Role / Device Role / Timing Role: Robust boost controller qualified for industrial temp range with guaranteed 250 ns min-OFF-time stability across voltage and temperature. Use Value: Stable 20 mA regulation and 1.5 V OVP hysteresis prevent false trips during thermal cycling or ESD events in harsh environments. |
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 |
|---|---|---|---|
| MAX1910EUT+T | Fixed 35 V OVP threshold; no RSET-adjustable peak current; uses external MOSFET | Requires additional FET, gate driver, and current-sense resistor - larger footprint and higher BOM cost | Select when design requires external switch control or tighter OVP tolerance (±2%) |
| TPS61160DRVR | Higher 40 V output capability; I²C programmable current; 2 MHz fixed-frequency PWM mode | Supports digital dimming and multi-string configurations but consumes more quiescent current (25 µA vs. <1 µA) | Select when system-level brightness calibration or multiple independent LED strings are required |
Compared with MAX1910EUT+T and TPS61160DRVR, STLD40DPMR offers lowest component count, smallest PCB area (QFN8 3×3 mm), and lowest shutdown current - making it optimal for cost-sensitive, space-constrained, battery-powered LCD backlight designs where analog PWM dimming suffices.
Availability
STLD40DPMR is available at Aetrix Electronics and suitable for LCD backlighting in smartphones, PDAs, portable medical displays, and industrial handheld terminals requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for STLD40DPMR 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 chips for automotive, industrial, and consumer markets.
STLD40DPMR belongs to ST's LED lighting driver product line, engineered specifically for low-input-voltage, high-efficiency boost conversion in portable display backlight applications with minimal external components.
FAQ
What is the recommended inductor value and saturation current for STLD40DPMR?
The datasheet specifies a 4.7 µH inductor with ISAT ≥ 1 A (when RSET = GND) and DCR ≤ 1 Ω. Recommended part is a shielded power inductor such as Coilcraft MSS5131-472ML or equivalent, rated for ≥1.2 A DC saturation to ensure stable operation across temperature and input voltage range.
Can STLD40DPMR drive more than 10 white LEDs?
No - the device is characterized and specified for up to 10 white LEDs (VO ≤ 37 V). Attempting to drive longer strings risks exceeding the 44 V absolute maximum rating at VO/SW pins and may trigger OVP continuously or cause premature failure due to sustained overvoltage stress on internal MOSFET.
How does PWM dimming work on the EN pin, and what frequency range is supported?
Applying a logic-low signal to EN disables the controller; a low-frequency square wave (typically 100–500 Hz) modulates LED brightness proportionally to duty cycle. The IC responds within microseconds, supporting smooth dimming without visible flicker or color shift when paired with appropriate LED capacitance and layout.
Is the NC pin (Pin 5) required to be left floating, or can it be tied to GND?
Pin 5 is internally unconnected and must remain floating per ST's layout recommendations. Grounding it may create unintended parasitic paths or coupling; ST explicitly states "N.C. Not connected" in the pin description table and recommends no solder mask opening or trace routing to this pad.
STLD40DPMR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-VDFN Exposed Pad
- 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):
- 3V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 37V
- Current - Output / Channel:
- 20mA
- Frequency:
- -
- Dimming:
- PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-QFN (3x3)
STLD40DPMR FAQ
1.How can I place an order for STLD40DPMR through Aetrix?
Please submit a Request for Quotation (RFQ) for STLD40DPMR 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 STLD40DPMR reliable?
The price and inventory of STLD40DPMR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STLD40DPMR is usually 5 days.
3.What payment methods are accepted for STLD40DPMR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STLD40DPMR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STLD40DPMR?
STLD40DPMR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STLD40DPMR 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 STLD40DPMR?
For technical support, including STLD40DPMR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STLD40DPMR requirements.
6.How does Aetrix verify that STLD40DPMR is sourced from the original manufacturer or authorized distributors?
All STLD40DPMR 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 STLD40DPMR meets industry standards.
7.What is the process for return or replacement of STLD40DPMR?
All STLD40DPMR units undergo pre-shipment inspection (PSI). If there is an issue with STLD40DPMR, 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 STLD40DPMR part is unused and in its original packaging.
Return procedure for STLD40DPMR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STLD40DPMR Tags
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BCR402RE6327HTSA1
Infineon Technologies
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BCR430UXTSA2
Infineon Technologies
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BCR420UE6433HTMA1
Infineon Technologies
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BCR420UE6327HTSA1
Infineon Technologies
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BCR421UE6327HTSA1
Infineon Technologies
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LYT1604D-TL
Power Integrations
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HV9910CLG-G
Microchip Technology
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CL2N8-G
Microchip Technology
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BCR420UW6-7
Diodes Incorporated
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BCR421UW6-7
Diodes Incorporated
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BCR420UFD-7
Diodes Incorporated
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BCR421UFD-7
Diodes Incorporated
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