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Texas Instruments LM3503ITL-16/NOPB
- Part No.:
- LM3503ITL-16/NOPB
- Manufacturer:
- Texas Instruments
- Category:
- LED Drivers
- Package:
- 10-WFBGA, DSBGA
- Datasheet:
-
LM3503ITL-16/NOPB.pdf
- Description:
- IC LED DRVR RGLTR PWM 10TUSMD
- Quantity:
- Payment:
- Shipping:
Inventory:3,388
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Product details
Overview
LM3503ITL-16/NOPB from Texas Instruments is a dual-display constant-current white LED driver IC with analog brightness control, 16 V over-voltage protection, 1 MHz switching frequency, and 2.5–5.5 V input range. It drives up to 10 LEDs (5 per display) in portable dual-backlight systems using internal PMOS/NMOS FET switches and feedback-controlled current regulation.
For engineers reviewing the LM3503ITL-16/NOPB datasheet, LM3503ITL-16/NOPB pinout, LM3503ITL-16/NOPB application, or LM3503ITL-16/NOPB equivalent, key selection criteria include OVP threshold (16 V), dual enable logic for MAIN/SUB display segmentation, analog Cntrl-pin dimming interface, and WQFN-16 thermal performance (θJA = 49°C/W).
Technical Context
The LM3503ITL-16/NOPB implements an asynchronous current-mode PWM controller with cycle-by-cycle current limiting, dedicated UVP (2.5 V on-threshold) and OVP (16 V on-threshold), soft-start, and thermal shutdown. Its dual-FET architecture separates MAIN (VOUT1–VOUT2) and SUB (VOUT2–Fb) LED string segments via En1/En2 logic.
It uses a fixed 1 MHz oscillator and error amplifier-based feedback loop referenced to VFb = 0.55 V (typ), with analog brightness control achieved by scaling VFb via external DC voltage on the Cntrl pin (0.2–3.5 V range). No external compensation is required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| OVP Threshold | 16 V (on-threshold ±0.5 V); prevents damage during LED open-circuit or removal |
| Input Voltage Range | 2.5 V to 5.5 V; supports single-cell Li-ion and multi-cell alkaline battery inputs |
| Switching Frequency | 1 MHz (±20%); enables compact LC filter design with <22 µH inductors |
| Feedback Voltage | 0.55 V (typ); sets regulated LED current via external sense resistor at Fb pin |
| Peak Current Limit | 400 mA (typ at 25°C); limits inductor peak current to protect NMOS switch N1 |
| Thermal Resistance θJA | 49°C/W (WQFN-16 package); enables 1.2 W max power dissipation at 85°C ambient |
| Enable Logic Thresholds | VEN1/VEN2 ≥1.4 V = ON; ≤0.3 V = OFF; supports direct GPIO control without level-shifting |
Pinout & Package
LM3503ITL-16/NOPB uses a 16-pin Thin WQFN (RGH0016A) package with exposed die attach pad (DAP) soldered to PCB ground for thermal management. Height <1 mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Input supply connection | Accepts 2.5–5.5 V; requires local 4.7 µF ceramic capacitor to minimize input ripple and EMI |
| Sw | Power NMOS drain | Connects to inductor; high di/dt node requiring short wide trace to reduce EMI and conduction loss |
| En1 / En2 | MAIN/SUB display enable controls | Logic-level inputs (0.3 V/1.4 V thresholds); control PMOS/NMOS FET switches independently for dual-string segmentation |
| Fb | Current-sense feedback node | Monitors voltage across external current-sense resistor; regulates LED current to ILED = VFb/Rsense |
| Cntrl | Analog brightness control input | DC voltage (0.2–3.5 V) scales feedback reference; enables smooth analog dimming without PWM filtering |
| VOUT1 | PMOS source & OVP sensing | OVP detection point; connects to cathode of MAIN display LED string and Schottky diode anode |
| VOUT2 | NMOS/PMOS drain junction | Interconnect node between MAIN and SUB strings; must be bypassed with 100 nF if unused |
| AGND / PGND | Analog & power ground returns | Separate pins require low-impedance star connection to DAP; prevents noise coupling into feedback path |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent display control | En1/En2 pins enable selective MAIN-only, SUB-only, or both-on operation-no external logic required |
| 16 V integrated OVP | Hardware-enforced output voltage clamp eliminates need for external Zener or TVS at VOUT1 |
| Analog brightness interface | Cntrl pin accepts DC voltage (not PWM), simplifying dimming circuitry and eliminating RC filter design effort |
| Internal soft-start | Gradually ramps current limit at startup to suppress inrush current into output capacitors and LED strings |
| No external compensation | Stable operation across full load and input range without loop compensation components |
Applications
| Cellular Phone Dual Display | PDA Main + Subscreen Backlight |
|---|---|
Use Scenario: Simultaneous backlighting of primary LCD and secondary status OLED in clamshell or slider phones. IC Role / Device Role / Timing Role: Constant-current driver with independent MAIN/SUB enable logic and 16 V OVP for robustness against LED string faults. Use Value: Eliminates need for two separate boost drivers; reduces BOM count and PCB area while enabling synchronized or independent dimming. | Use Scenario: Powering main touchscreen and auxiliary keypad/backlight in handheld PDAs with variable LED count (2–5 per string). IC Role / Device Role / Timing Role: Dual-channel white LED driver with analog Cntrl-pin dimming and 1 MHz switching for low EMI in noise-sensitive RF environments. Use Value: Achieves >80% peak efficiency across 2.5–5.5 V input range, extending battery life without compromising brightness uniformity. |
| Portable Media Player UI + Indicator | Industrial Handheld Terminal Display |
Use Scenario: Driving high-brightness main display and low-power status indicator LEDs in MP3/video players. IC Role / Device Role / Timing Role: Dual-output LED driver with shutdown mode (En1=En2≤0.3 V) and ultra-low 0.3 µA shutdown current. Use Value: Enables zero-current LED off-state and rapid wake-up, supporting instant-on UX and long standby duration. | Use Scenario: Backlighting ruggedized LCD and auxiliary warning LEDs in warehouse scanners or field meters operating at −40°C to +85°C. IC Role / Device Role / Timing Role: Industrial-grade LED driver with guaranteed operation across −40°C to +125°C junction temperature and 2 kV HBM ESD rating. Use Value: Maintains stable current regulation and OVP protection under thermal cycling and electrostatic-prone environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-display LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM3503ITL-25/NOPB | 25 V OVP threshold; higher current limit (600 mA typ); identical pinout and control interface | Suitable for longer LED strings (up to 8 LEDs per channel) or higher forward voltage displays | Select when Vf × LED count exceeds 14 V; otherwise LM3503ITL-16/NOPB offers tighter OVP margin and lower cost |
| TPS61165RTVR | Single-output, 40 V OVP, I²C interface, no dual-enable logic; 3 mm × 3 mm WQFN-16 | Lacks native dual-string segmentation; requires external logic or MCU coordination for MAIN/SUB control | Choose only if system already uses I²C bus and dual enable is implemented in firmware; not a drop-in replacement |
Compared with LM3503ITL-25/NOPB, the LM3503ITL-16/NOPB provides tighter over-voltage protection for shorter LED strings and lower quiescent current in non-switching mode (0.5 mA vs. 0.7 mA), while retaining identical thermal performance and enable logic behavior. Against TPS61165RTVR, it delivers hardware-native dual-string control without firmware overhead but lacks digital configurability.
Availability
LM3503ITL-16/NOPB is available at Aetrix Electronics and suitable for portable electronics, handheld industrial terminals, and consumer media devices requiring stable component supply, dual-display LED backlighting, and analog dimming capability.
Supply support for LM3503ITL-16/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 specializing in analog, embedded processing, and high-reliability ICs for industrial, automotive, and portable applications.
The LM3503 product line delivers integrated dual-display LED drivers optimized for space-constrained battery-powered devices, combining analog dimming, hardware enable logic, and robust protection in low-profile WQFN packages.
FAQ
What is the maximum number of LEDs the LM3503ITL-16/NOPB can drive per display?
The LM3503ITL-16/NOPB supports up to 5 white LEDs per display segment (MAIN or SUB), based on its 16 V OVP threshold and typical forward voltage assumptions (3.2 V per LED). With 5 LEDs × 3.2 V = 16 V, the device operates at its OVP limit-ensuring safe regulation without triggering shutdown. Driving more than 5 LEDs risks exceeding the 16 V threshold and activating over-voltage protection.
How does the Cntrl pin on the LM3503ITL-16/NOPB set LED brightness?
The Cntrl pin on the LM3503ITL-16/NOPB accepts a DC voltage (0.2–3.5 V) that linearly scales the internal feedback reference. At Cntrl = 0 V, LED current is near-zero; at Cntrl = 3.5 V, VFb reaches 0.6 V (max), setting maximum current. The relationship is VFb ≈ 0.156 × VCntrl, so LED current ILED = VFb/Rsense. This enables true analog dimming without PWM filtering components.
Can the LM3503ITL-16/NOPB operate with only one display enabled?
Yes-the LM3503ITL-16/NOPB supports three operational states via En1 and En2: MAIN-only (En1 ≥1.4 V, En2 ≤0.3 V), SUB-only (En1 ≤0.3 V, En2 ≥1.4 V), or both-on (En1 ≥1.4 V, En2 ≥1.4 V). If both pins are ≤0.3 V, the device enters shutdown mode with 0.3 µA quiescent current. This flexibility allows dynamic allocation of LED resources without external switches.
What is the purpose of the separate AGND and PGND pins on the LM3503ITL-16/NOPB?
The LM3503ITL-16/NOPB separates AGND (analog ground) and PGND (power ground) to isolate noise-sensitive feedback circuitry from high-di/dt switching currents. AGND connects to the Fb and Cntrl pins' reference; PGND carries inductor return and FET source currents. Both must tie to the same low-impedance ground plane-ideally at the DAP-to prevent ground bounce from corrupting current regulation accuracy.
Does the LM3503ITL-16/NOPB require external compensation components?
No-the LM3503ITL-16/NOPB is internally compensated and operates stably across its full input voltage (2.5–5.5 V), output load (2–10 LEDs), and temperature (−40°C to +125°C) ranges without external compensation capacitors or resistors. This simplifies layout, reduces BOM count, and eliminates tuning effort during design validation.
LM3503ITL-16/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 10-WFBGA, DSBGA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 2
- Voltage - Supply (Min):
- 2.5V
- Voltage - Supply (Max):
- 5.5V
- Voltage - Output:
- 16V
- Current - Output / Channel:
- 400mA (Switch)
- Frequency:
- 1MHz
- Dimming:
- Analog, PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-TµSMD (1.9x2.07)
LM3503ITL-16/NOPB FAQ
1.How can I place an order for LM3503ITL-16/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3503ITL-16/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 LM3503ITL-16/NOPB reliable?
The price and inventory of LM3503ITL-16/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3503ITL-16/NOPB is usually 5 days.
3.What payment methods are accepted for LM3503ITL-16/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3503ITL-16/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3503ITL-16/NOPB?
LM3503ITL-16/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3503ITL-16/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 LM3503ITL-16/NOPB?
For technical support, including LM3503ITL-16/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3503ITL-16/NOPB requirements.
6.How does Aetrix verify that LM3503ITL-16/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3503ITL-16/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 LM3503ITL-16/NOPB meets industry standards.
7.What is the process for return or replacement of LM3503ITL-16/NOPB?
All LM3503ITL-16/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3503ITL-16/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 LM3503ITL-16/NOPB part is unused and in its original packaging.
Return procedure for LM3503ITL-16/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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