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LM3503SQX-44

LM3503SQX-44 DC DC Regulator, 44V Boost, 1MHz, Obsolete

MPNLM3503SQX-44
Obsolete

Texas Instruments LM3503SQX-44, DC DC Regulator, Step-Up (Boost) topology, 2 outputs, 44V output, 750mA switch, 1MHz switching frequency, Analog and PWM dimming, 16-WFQFN exposed pad, -40°C to 85°C.

Texas Instruments LM3503SQX-44 datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

LM3503SQX-44 specifications
ParameterValue
TypeDC DC Regulator
MountingSurface Mount
Voltage - output44V
Supply voltage5.5V
Current - output (Channel)750mA (Switch)
Frequency1MHz
I/O channels2
Operating temperature-40°C~85°C(TA)
DimmingAnalog, PWM
PackageTape & Reel (TR)
TopologyStep-Up (Boost)
ApplicationsBacklight
Case16-WFQFN Exposed Pad
Internal switchYes

Product details

Boost regulator for LED backlighting — what the specs mean

This is a step-up (boost) DC-DC regulator designed for backlight applications. It integrates two outputs with a 750 mA internal switch, switching at 1 MHz, and delivers up to 44 V output. Dimming is supported via both Analog and PWM methods — the PWM dimming path gives a wider contrast ratio for LCD backlights, while analog dimming suits simpler brightness control where the PWM switching noise might couple into the display driver.

Package fit and temperature envelope

Housed in a 16-WFQFN exposed pad package (4x4 mm body), it is surface-mount only. No external power sequencing required beyond the usual input decoupling.

Frequently asked questions

Does LM3503SQX-44 require external components?

Yes, like any boost regulator, it requires external components — typically an inductor, input and output capacitors, and feedback resistors (though the output is fixed at 44 V, so the feedback divider is internal). The datasheet application circuit shows the recommended component values for stability and efficiency at the 1 MHz switching frequency.