Charge-pump LED driver — key parametrics for backlight designs
The LM3538TME/NOPB: This is an 8-output switched-capacitor (charge pump) regulator, not a linear or inductive boost — the topology matters for noise and efficiency. Each channel delivers up to 25 mA, with a combined output voltage range of 2 V to 4 V, making it suited for driving parallel LED strings in small-panel backlights. Switching at 1.3 MHz, the charge pump keeps external capacitors small — typically 0.1 µF to 1 µF ceramic — but the switching noise couples into the output; layout should keep the pump caps close to the IC and avoid routing sensitive traces under the BGA. PWM dimming is supported on the control input, which lets the downstream LED current be modulated without altering the charge-pump regulation loop — common for brightness control in display backlights.
Package and reflow — 30-DSBGA considerations
The 30-DSBGA (0.4 mm pitch, 30-ball WFBGA) demands a controlled reflow profile and a clean solder-paste stencil. Operating temperature spans -30°C to 85°C — this is an industrial/commercial grade, not automotive. The part will survive a typical indoor or portable-device thermal environment but is not rated for under-hood or extended high-temp exposure.
Compliance and documentation
RoHS3 compliant — the /NOPB suffix confirms lead-free and no added halogens per TI's NOPB designation.