I’ve got samples of interersting DC/DC converter from TI: TPS61040. Main application is to drive small white LEDs from a battery cell or two. Input voltage range is from 1,8V to 6V. Ideal for two AA or single Li-xx cell. Schematics is very simple. Only few external components are required: a coil, caps and schottky diode:
TPS61040 housing is SOT-23-5, other components are conventionally packaged. It’s ideal combination for home made, single sided, toner transfer PCB:
Top layer is prepared in 1:1 scale for TT transfer here: PCB TPS61040. Don’t forget to set printeing scale to 1:1 !
Finished PCB is about 12×16mm. First assemble all SMD components, followed by wires and LEDS.
Circuit has enable input signal. To switch the LEDs on, connect EN (pin 4) + battery voltage.
Simplest housing for the module is shrink tube:
And finally…. Altium project for TPS61040DBV