Step-up IC suggestions?

[naterg]

Hi,

I'm in need of a step-up IC for a constant voltage power supply for a battery-operated toy I'm making. I have the following specifications. Any suggestions or even references to possible sources for assistance or reading material would be greatly appreciated.

Requirements:
1. Must be powered from 3 alkaline cells and work with input as low as 2.7V; and
2. Must be capable of supplying at least 5.0V; and
3. Must be capable of continuously supplying at least 320mA; and
4. Must be easily sourced (currently available at Mouser or Digikey or sample easily obtainable by Joe-blow tinkerer); and
5. Must have shutdown mode that can be actuated with MCU; and
6. Typical supply current in shutdown mode must not exceed 50uA

Preferences (but not absolute requirements):
7. Output 5.5V
8. Through-hole
9. The fewer the required components, the better.
10. Cheap?

Thank you for your time and consideration.

 

[D.A.(Tony)Stewart]

LM2700

https://webench.ti.com/webench5/pow...O1I=0.5&O1V=5.5&op_TA=30&application=SWITCHER

 

[naterg]

Thank you! I plan to give this a try.

 

[KlausST]

Hi,

Have a look at www.linear.com.
Power supply, switching regulators.

Klaus

 

[BradtheRad]

5. Must have shutdown mode that can be actuated with MCU;

This suggests you plan to put a microcontroller onboard with a 5V supply, which is to be shut off by the microcontroller.

I have a funny question:
By any chance, is the microcontroller powered by the 5V supply? Is the microcontroller expected to turn off its own power supply? (I'm not saying this won't work.)

I guess you'll switch on the step-up converter manually?

Anyway here is a voltage doubler. It is based on stacked capacitors and an H-bridge. The load is connected across the capacitors.

It will work down to 3 V or so. Notice if you want 320 mA output at 5V, your batteries must provide around 1 A input at 3V. You may not get this from batteries which are drained to that extent.



At a supply V of 4.5V (fresh batteries), you'll get a higher output voltage. It will require some kind of feedback control.