My Inquiry
My Account
Texas Instruments LM3509SDE/NOPB
- Part No.:
- LM3509SDE/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 10-WFDFN Exposed Pad
- Datasheet:
-
LM3509SDE/NOPB.pdf
- Description:
- IC LED DRVR RGLTR I2C 30MA 10SON
- Quantity:
- Payment:
- Shipping:
Inventory:452
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM3509SDE/NOPB from Texas Instruments is a dual-output white LED/OLED display bias supply IC featuring two independently configurable current sinks (MAIN and SUB/FB), 32-step I²C-compatible exponential brightness control, 30 mA per string maximum output, and adaptive boost regulation operating from 2.7V to 5.5V input - used in portable LCD backlighting and OLED panel power systems.
For engineers reviewing the LM3509SDE/NOPB datasheet, LM3509SDE/NOPB pinout, LM3509SDE/NOPB application, or LM3509SDE/NOPB equivalent, key selection considerations include dual-mode operation (LED+LED or LED+OLED), 0.15% current matching in unison mode, 21 V over-voltage protection, 1.27 MHz fixed-frequency switching, and WSON-10 thermal performance for space-constrained handheld displays.
Technical Context
The LM3509SDE/NOPB implements a current-mode PWM boost converter with dual regulated outputs: MAIN operates as a constant-current sink up to 30 mA, while SUB/FB functions either as a second current sink or as a 1.21 V feedback input for OLED voltage regulation up to 21 V. Adaptive regulation dynamically adjusts output voltage to maintain ≥500 mV headroom across both strings.
Control is delivered via an I²C-compatible interface (7-bit address 0x36) supporting independent or unison brightness programming, ramp-rate configuration (4 settings), active-low hardware reset, and GPIO reconfiguration. Internal soft-start limits inrush current, and thermal shutdown engages at 140°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.7 V to 5.5 V - supports single-cell Li-ion and USB-powered portable systems without external LDO. |
| Max Output Current | 30 mA per string - sets upper limit for driving up to 5-series white LEDs per channel. |
| Current Matching Accuracy | 0.15% typ. in unison mode - ensures consistent luminance across dual display zones without manual calibration. |
| Switching Frequency | 1.27 MHz fixed - enables use of compact 1–2.2 µF ceramic output capacitors and sub-3 mm inductors. |
| OVP Threshold | 21.2 V (min) - protects OLED panels and low-voltage output caps during open-circuit or load-dump conditions. |
| I²C Address | 0x36 (7-bit) - allows daisy-chaining with other TI display power ICs on shared bus without address conflict. |
| Thermal Shutdown | 140°C activation - prevents permanent damage during sustained high-power backlight operation in sealed enclosures. |
Pinout & Package
LM3509SDE/NOPB uses a thermally enhanced 10-pin WSON package (3 mm × 3 mm × 0.8 mm) with exposed DAP for PCB-level heat dissipation. Pin 1 is MAIN; pin 10 is SCL; DAP is internally connected to GND.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - MAIN | Main current sink input | Connects to cathode of first LED string; regulates current up to 30 mA with 500 mV headroom requirement. |
| 2 - SUB/FB | Secondary current sink or 1.21 V feedback input | Configurable via GP register: drives second LED string or sets VOLED = 1.21 × (1 + R1/R2) for OLED bias. |
| 3 - SET | Current setting reference | Resistor from SET to GND sets max current: ILED_MAX = 192 × 1.244 V / RSET. |
| 4 - VIO | I²C logic voltage reference | Defines SCL/SDA logic thresholds (VIH = 0.7×VIO); supports 1.4–VIN range for mixed-voltage system interfacing. |
| 5 - RESET/GPIO | Active-low reset or programmable I/O | Pulling low resets all registers to default; configured as open-drain GPIO for status signaling or sync control. |
| 6 - SW | Internal NMOS switch drain | Connects to boost inductor; requires Schottky diode and proper layout to minimize EMI and conduction loss. |
| 7 - OVP | Over-voltage sense input | Monitors output rail directly; triggers shutdown if VOVP exceeds 21.2 V - must connect to COUT+ node. |
| 8 - IN | Power input | Accepts 2.7–5.5 V; requires ≥1 µF ceramic bypass capacitor placed near pin to stabilize input impedance. |
| 9 - SDA | I²C data line | Open-drain bidirectional; requires external pull-up to VIO; supports standard/fast-mode timing per Figure 2. |
| 10 - SCL | I²C clock input | Drives internal state machine; clock period ≥2.5 µs required for reliable register access and brightness updates. |
Key Features
| Feature | Design Value |
|---|---|
| Dual-mode output configuration | Supports either dual white LED strings (up to 10 total LEDs) or hybrid white LED + OLED panel (VOLED ≤21 V). |
| 32-step exponential dimming | Enables smooth, perceptually linear brightness control across full 0–100% range without MCU-side gamma correction. |
| True shutdown isolation | Disables MAIN and SUB/FB sinks completely (high-Z), eliminating leakage current into disconnected LED strings. |
| Integrated soft-start | Ramps average input current from 0 to 450 mA in 1.2 ms - prevents input rail sag and audible coil whine at power-on. |
| 0.15% current matching (unison) | Ensures <±0.5% luminance deviation between dual display zones under identical register settings and temperature. |
Applications
| Portable Dual-Display Backlighting | OLED Panel + LED Indicator Bias |
|---|---|
|
Use Scenario: Dual-screen handheld device with main LCD and secondary status display. IC Role / Device Role / Timing Role: LM3509SDE/NOPB provides independent 20 mA current regulation to each display using BMAIN/BSUB registers via I²C. Use Value: Eliminates need for separate boost converters and reduces BOM count by 40% versus discrete solutions. |
Use Scenario: Smartwatch with primary OLED screen and secondary RGB LED notification ring. IC Role / Device Role / Timing Role: LM3509SDE/NOPB configures SUB/FB as 18 V OLED regulator while MAIN drives 30 mA LED string. Use Value: Single IC delivers both high-efficiency panel bias and precise indicator current with shared thermal path. |
| Large-Format Industrial LCD Backlight | Medical Diagnostic Display Power |
|
Use Scenario: 7-inch industrial HMI with edge-lit LED backlight requiring uniform brightness across 2 parallel strings. IC Role / Device Role / Timing Role: LM3509SDE/NOPB operates in unison mode (UNI=1) to match MAIN/SUB currents within 0.15%. Use Value: Reduces visible banding artifacts and eliminates post-calibration trimming steps in production test. |
Use Scenario: Portable ultrasound monitor needing fail-safe display power with thermal and OVP monitoring. IC Role / Device Role / Timing Role: LM3509SDE/NOPB delivers regulated 21 V OLED bias with automatic shutdown on OVP or TJ>140°C. Use Value: Meets IEC 62304 Class B safety requirements via integrated protection features and no external sensing components. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-output display bias applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS61165DRVR | Single-output, 40 V boost with analog/PWM dimming; no I²C interface or dual-sink capability. | Suitable only for single-string LED backlighting; lacks OLED voltage regulation mode. | Select when cost sensitivity outweighs need for dual-channel control or OLED support. |
| MAX16832ATP+ | Two independent boost channels, but no integrated I²C controller; requires external MCU for brightness sequencing. | Supports dual LED strings but adds firmware complexity and board area for external logic. | Choose when deterministic timing control or custom dimming profiles justify added design effort. |
Compared with TPS61165DRVR and MAX16832ATP+, the LM3509SDE/NOPB uniquely integrates dual-sink current regulation, I²C-based 32-step dimming, and OLED voltage mode in one WSON-10 package - reducing component count, layout area, and firmware overhead for portable display systems.
Availability
LM3509SDE/NOPB is available at Aetrix Electronics and suitable for portable LCD backlighting, OLED panel biasing, medical diagnostic displays, industrial HMIs, and consumer handheld devices requiring stable component supply across multi-year production cycles.
Supply support for LM3509SDE/NOPB 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
Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and connectivity solutions with emphasis on power efficiency, reliability, and system integration.
The LM3509SDE/NOPB belongs to TI's display power management product line, engineered specifically for space-constrained, battery-operated portable displays requiring high-efficiency dual-output bias with minimal external components.
FAQ
What is the maximum number of white LEDs the LM3509SDE/NOPB can drive?
The LM3509SDE/NOPB can drive up to 10 white LEDs total - 5 in series per string - at 30 mA per string in dual-LED mode. When configured for OLED + LED mode, it supports up to 5-series white LEDs on MAIN while regulating up to 21 V on SUB/FB for OLED panels. The actual count depends on forward voltage per LED and input voltage; for example, at VIN = 3.6 V and VF = 3.2 V, up to 3 LEDs per string remain within regulation margin.
Does the LM3509SDE/NOPB support true shutdown isolation for LED strings?
Yes, the LM3509SDE/NOPB provides true shutdown isolation: when ENM or ENS bits in the General Purpose register are cleared, the corresponding MAIN or SUB/FB current sink enters high-impedance state, eliminating leakage current into disconnected LED strings. This prevents unintended glow in off-state displays and improves system-level power efficiency during sleep modes.
How does the LM3509SDE/NOPB achieve 0.15% current matching between MAIN and SUB/FB?
The LM3509SDE/NOPB achieves 0.15% typical current matching in unison mode (UNI = 1) by sharing a single brightness register (BMAIN) to control both sinks simultaneously and using matched internal current mirror circuitry referenced to the same SET pin voltage. This eliminates independent DAC errors and process mismatches that cause drift in non-unison operation, where matching degrades to 1% typical.
Can the LM3509SDE/NOPB be used to power both an OLED panel and a white LED indicator simultaneously?
Yes - the LM3509SDE/NOPB supports simultaneous OLED panel bias and white LED indicator operation: configure SUB/FB as feedback input (OLED = 1) to regulate VOLED up to 21 V, while MAIN drives the LED indicator at up to 30 mA. Ensure ≥300 mV headroom at MAIN (i.e., VOLED − VF_LED ≥ 0.3 V) to maintain current regulation integrity during dynamic brightness changes.
What is the purpose of the OVP pin on the LM3509SDE/NOPB?
The OVP pin on the LM3509SDE/NOPB monitors the output voltage directly and triggers automatic shutdown if VOVP exceeds 21.2 V (min). It must be connected to the positive terminal of the output capacitor to enable fast overvoltage response. This protects downstream OLED panels and low-voltage ceramic capacitors from overstress during open-circuit or transient fault conditions - a critical safety feature absent in basic boost controllers.
LM3509SDE/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 10-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 2
- Voltage - Supply (Min):
- 2.7V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 21V
- Current - Output / Channel:
- 30mA
- Frequency:
- 1.27MHz
- Dimming:
- I2C
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-SON (3x3)
LM3509SDE/NOPB FAQ
1.How can I place an order for LM3509SDE/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3509SDE/NOPB 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 LM3509SDE/NOPB reliable?
The price and inventory of LM3509SDE/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3509SDE/NOPB is usually 5 days.
3.What payment methods are accepted for LM3509SDE/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3509SDE/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3509SDE/NOPB?
LM3509SDE/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3509SDE/NOPB 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 LM3509SDE/NOPB?
For technical support, including LM3509SDE/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3509SDE/NOPB requirements.
6.How does Aetrix verify that LM3509SDE/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3509SDE/NOPB 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 LM3509SDE/NOPB meets industry standards.
7.What is the process for return or replacement of LM3509SDE/NOPB?
All LM3509SDE/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3509SDE/NOPB, 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 LM3509SDE/NOPB part is unused and in its original packaging.
Return procedure for LM3509SDE/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3509SDE/NOPB Tags
-
BCR402RE6327HTSA1
Infineon Technologies
-
BCR430UXTSA2
Infineon Technologies
-
BCR420UE6433HTMA1
Infineon Technologies
-
BCR420UE6327HTSA1
Infineon Technologies
-
BCR421UE6327HTSA1
Infineon Technologies
-
LYT1604D-TL
Power Integrations
-
HV9910CLG-G
Microchip Technology
-
CL2N8-G
Microchip Technology
-
BCR420UW6-7
Diodes Incorporated
-
BCR421UW6-7
Diodes Incorporated
-
BCR420UFD-7
Diodes Incorporated
-
BCR421UFD-7
Diodes Incorporated
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
