Boost regulator with 0.9 V minimum input and 800 mA switch
The TPS61028DRCR is a synchronous boost converter from Texas Instruments that steps up input voltages from as low as 0.9 V up to 6.5 V to an adjustable output between 1.8 V and 5.5 V. The integrated switch is rated for 800 mA, which sets the peak inductor current limit and therefore the maximum output current the converter can deliver — a key parameter when sizing the inductor and estimating the load budget. The 600 kHz switching frequency is fixed; the controller uses current-mode PWM regulation with internal compensation. Synchronous rectification is built in, which improves efficiency at moderate to heavy loads by replacing the external Schottky diode with a low-side MOSFET.
Thermal and package considerations for board layout
Compared to the LM2750 charge-pump boost (120 mA max output, 1.7 MHz, no synchronous rectification), the TPS61028DRCR delivers higher output current and better efficiency at higher loads, but requires an external inductor and has a larger footprint. The LMR33630 is a step-down (buck) converter — not a functional alternative for a boost application.
Active production with no obsolescence notice
ROHS3 compliance is confirmed.