LM3503ITL-35 - Dual 750mA LED Driver | Texas Instruments
MPN： LM3503ITL-35 ✓ 啟用中LM3503ITL-35 概覽
An LED driver is a specialized power-management integrated circuit that converts a supply into the controlled current required by one or more LEDs. A constant-current LED driver regulates output current rather than voltage because LED brightness and reliability depend strongly on current. The boost topology supports LED strings whose forward-voltage requirement exceeds the available input voltage. Within the power-management hierarchy, the LM3503ITL-35 is an LED driver, which is a DC-DC regulator specialized for illumination loads.
The verified data identifies two outputs, constant-current operation, analog brightness control, and PWM dimming as defining features. The switch rating of 750 mA provides a concrete current benchmark when sizing the converter, while the 800 kHz to 1.2 MHz frequency span places the device in a compact, high-frequency backlight-driver class. These features suit displays requiring separate illumination levels or coordinated dual-channel backlighting. Additional electrical limits, LED quantities, efficiency values, and dimming ratios were not supplied and therefore require verification in the manufacturer datasheet.
The device combines a boost-converter function with dedicated constant-current LED regulation. Its two-output architecture reduces the number of separate lighting channels required on a compact display PCB. Analog brightness control provides a direct brightness-control path, while PWM dimming supports display illumination modulation. The small surface-mount package is appropriate for space-constrained portable equipment, but the exposed-pad connection, assembly requirements, thermal limits, and maximum power dissipation must be handled according to the official board-layout guidance.
Typical uses include LCD module backlighting, dual-display portable equipment, tablet or instrument-panel illumination, and compact consumer products with two white-LED strings. For a portable system, the LM3503ITL-35 can generate the required LED current from a lower input voltage when configured as a boost converter. The designer must still confirm that the input source, inductor, diode, capacitors, feedback settings, and LED forward voltages support the intended strings.
The principal design task is validating the verified 750 mA switch rating against actual LED-string current and thermal conditions. Component selection must account for startup behavior, switching losses, inductor saturation current, and layout inductance. Because detailed threshold, timing, and absolute-maximum data are unavailable in the supplied excerpts, consult the manufacturer datasheet before release to production.
This page consolidates verified distributor specifications, sourcing information, replacement constraints, and practical design guidance. It also distinguishes confirmed electrical facts from parameters that still need manufacturer-documentation confirmation.
直接替換替代品，適用於 LM3503ITL-35 — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此產品無可直接替換的替代品。
申請替代品LM3503ITL-35 最大額定值與電氣特性
| Primary Device Type | Backlight LED driver |
| LED Type | White LED |
| 輸出數量 | 2 outputs |
| Current Regulation | Constant current |
| Converter Topology | PWM step-up boost |
| 切換頻率 | 800 kHz to 1.2 MHz |
| Switch Current Rating | 750 mA |
| Dimming Control | Analog brightness control and PWM dimming |
| 輸出電壓 | Up to 35 V |
| Technical Supply Voltage | 5.5 V maximum |
| Regulator Function | DC-DC regulator |
| Package Type | 10-pin micro-SMD |
| Package Dimensions | 1.9 mm x 2.07 mm |
| 安裝類型 | Surface mount |
| Supplier Order Suffix | /NOPB |
LM3503ITL-35 1.9 mm x 2.07 mm 腳位配置指南
LM3503ITL-35（1.9 mm x 2.07 mm 封裝）的腳位配置。 此功率元件具有閘極、汲極與源極端子。對於非極性封裝，請參閱製造商資料表以取得確切的第 1 腳方向與佈局詳細資訊。常見應用包括電源設計、馬達驅動與負載切換。
無詳細腳位定義資料： LM3503ITL-35.
請參閱 資料表 以查看完整腳位配置。
典型應用
LM3503ITL-35 適用於 6 應用s: Dual-Display Backlighting, Portable Tablet Lighting, Instrument-Panel Illumination, Battery-Powered Diagnostic Displays, Compact Test-and-Measurement Displays, Automotive-Style Dual Displays.
Dual-Display Backlighting
The LM3503ITL-35 fits dual-display backlighting because the verified device provides two constant-current outputs, analog brightness control, and PWM dimming in one 10-pin micro-SMD package. Place it behind the display's two LED strings and use the boost stage when the LED-string voltage exceeds the available rail. Its 800 kHz-to-1.2 MHz operating range supports compact high-frequency power conversion, while the 750 mA switch rating establishes a clear sizing benchmark. Confirm actual channel current, startup behavior, thermal dissipation, and both LED-string voltages in the manufacturer datasheet before committing the PCB layout.
Portable Tablet Lighting
The LM3503ITL-35 is appropriate for portable tablet lighting when the product uses two white-LED backlight channels and needs independent brightness adjustment in a small board area. Analog brightness control can establish an initial illumination level, while PWM dimming can modulate display brightness. Its two-output boost-driver topology reduces the component count compared with using unrelated regulators for each display channel. The package is approximately 1.9 mm by 2.07 mm, but battery current, converter efficiency, display-string voltage, and allowable light flicker still require application-specific validation as of 2026-10-23.
Instrument-Panel Illumination
The LM3503ITL-35 can support instrument-panel or control-display illumination when two LED arrays need controlled current from a shared boost-driver IC. Constant-current regulation is preferable to uncontrolled voltage drive because it makes LED operating current more repeatable. PWM dimming provides a usable modulation method, and the verified two-output organization simplifies channel management. Before deployment, compare the 750 mA switch rating against normal, maximum, and startup loads, then verify inductor saturation margin, diode reverse voltage, capacitor ripple current, and junction-temperature limits from the official documentation.
Battery-Powered Diagnostic Displays
The LM3503ITL-35 fits battery-powered diagnostic equipment that uses two display backlights and needs adjustable illumination across changing operating conditions. The boost architecture can raise a battery-derived input to the LED-string voltage, while constant-current control limits the primary brightness variable. Analog brightness control supports a continuous level command, and PWM dimming offers an alternate pulse-width-controlled path. The design remains constrained by available battery voltage and heat: high conversion ratios or sustained maximum current can reduce efficiency and raise component temperature, so both operating modes must be evaluated rather than relying only on the 750 mA switch figure.
Compact Test-and-Measurement Displays
The LM3503ITL-35 is suitable for compact test-and-measurement products with two illuminated display windows. Integrating both constant-current channels into a 10-pin micro-SMD device can simplify control and conserve board area compared with separate single-channel drivers. PWM dimming can support user-adjustable brightness, while analog brightness control can initialize or continuously command illumination. Because measurement displays may combine low and high brightness extremes, check minimum on-time, visible flicker, LED current accuracy, and loop stability using the manufacturer guidance; those timing and modulation values were not present in the supplied excerpts.
Automotive-Style Dual Displays
The LM3503ITL-35 can serve as a candidate for dual illuminated displays in vehicle-oriented equipment, but automotive qualification cannot be assumed from the available data. Its two constant-current outputs, analog brightness control, PWM dimming, and boost-converter operation align functionally with multi-display backlighting. Before using it in a safety- or production-critical automotive design, verify temperature range, transient tolerance, vibration handling, AEC-Q100 status, lamp-flicker requirements, and fail-safe behavior. None of those qualification details was supplied, so this use remains conditional rather than a claim of automotive readiness.
工程參考資料，適用於 LM3503ITL-35 — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 |
|---|---|
| Brand | Texas Instruments |
| Package | 10-pin micro-SMD, 1.9 mm x 2.07 mm |
| Number of Outputs | 2 |
| Switch Current Rating | 750 mA |
| Switching Frequency | 800 kHz to 1.2 MHz |
| Output Voltage | Up to 35 V |
| Technical Supply Voltage | 5.5 V maximum |
| Brightness Control | Analog brightness control and PWM dimming |
主要差異化特點
- Integration for two backlight channels (對比Generic single-channel boost LED driver)
- Two brightness-control methods (對比Dimmable single-output driver with PWM only)
- Documented switch-current benchmark (對比Unspecified low-power LED-backlight controller)
設計說明
Begin with an input-voltage and LED-string voltage budget before selecting external power components. Because the LM3503ITL-35 uses boost conversion and has an output rating up to 35 V, the input source must still support the required duty cycle and startup demand. Treat the verified 750 mA switch rating as a device rating, not an unconditional output-current command. Confirm actual LED current, worst-case input current, converter efficiency, inductor saturation current, diode reverse-voltage margin, and output-capacitor ripple rating against the manufacturer datasheet.
Keep the high-current boost-loop path compact because its 800 kHz-to-1.2 MHz switching range leaves little margin for oversized PCB inductance. Place the switching node over as little copper area as practical, keep high-di/dt loops short, and follow the manufacturer's recommended component placement and grounding arrangement. The supplied data does not provide a definitive exposed-pad or thermal-via pattern, so use the official package drawing and layout example instead of inferring one from distributor package dimensions.
Do not substitute the LM3503ITL-35/NOPB ordering code for a separately verified electrical equivalent or assume that any two-output LED driver is pin compatible. The verified data does not disclose a complete pin map, absolute maximum ratings, PWM timing, or dimming ratios. Prototype only after checking every package terminal, both output-channel settings, startup behavior, shutdown behavior, and fault tolerance in the manufacturer datasheet. Record LED current across temperature as part of production validation.
合規資訊
The supplied distributor and datasheet-index records do not provide explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statements. Compliance must be confirmed from the current manufacturer product documentation before qualification.
