SparkFun sm�´l Power Board AAA

Our RedBoards are great. But don't they sometimes seem a little BIG?!

Enter sm�´l, a new range of boards which are both small in size and small on current draw. It's a sm�´l world!

The sm�´l Power Board AAA is an intelligent power board for the sm�´l ecosystem. Designed to boost the voltage from one or two AAA or AA cells up to 3.3V, you would expect this board to have a TPS61200 regulator on it, and indeed it does. (That's the same regulator we use on our LiPower - Boost Converter.) But you probably wouldn't expect it to have an AVR ATtiny43 microcontroller on it. So why have we included one?

This is an intelligent power board for smÃ�´l. The power board takes control of the 3.3V power for the whole smÃ�´l stack. The processor board can then instruct the power board to put the entire smÃ�´l stack into deep sleep for a pre-defined interval. Sleep intervals of 10's of milliseconds to several days are possible. In deep sleep, the only device left powered is the ATtiny43 and that reduces the current draw to 12µA. Yes, you read that right, 12 microamps! smÃ�´l makes it possible for your battery life to be measured in months not days! We used the fantastic Otii Arc Power Analyzer to help us reduce the sleep current as much as possible.

Our sm�´l Power Board Arduino Library has examples to get you started.

sm�´l is an ecosystem of miniature processor boards, peripheral boards, power boards and accessories. Designed to be both physically small and to have the smallest possible current draw, sm�´l is the perfect choice for applications like wildlife tracking or discrete long-term monitoring. sm�´l boards are designed to stack one on top of the other, using 16-way 0.5mm-pitch Flexible Printed Circuits (FPCs) to provide the interconnect from one board to the next. Looking for a really compact solution for your next project? This is it!

We will be adding new sm�´l boards over the coming months. Don't see the board you need for your application? Reach out to us via the SparkX Forum and tell us which board(s) we should add next!

Features:

Boost Regulator:

• TPS61200
  • I_OUT (max) @ V_OUT = 3.3V, V_IN = 1.5V: ~550mA
  • I_OUT (max) @ V_OUT = 3.3V, V_IN = 3.0V: ~1500mA
  • I_Q: 55µA

On-Board Microcontroller:

• ATtiny43U 8-bit AVR Microcontroller
  • 4KBytes Flash
  • 64Bytes EEPROM
  • 256Bytes SRAM
  • On-chip Boost Converter (V_IN (min): 0.7V)

Sleep Current Draw:

• 12µA (with ATtiny43 in Power-Down Mode, V_IN = 3.0V) (measured by Otii Arc)

sm�´l Specifics:

• Interface: I²C
  • ATtiny43 Default Address: 0x50
• PROC_PWR_EN:
  • The power board pulls PROC_PWR_EN low to disable the regulator on the processor board

Dimensions:

• Length: 1.60" (40.6mm)
• Width: 0.42" (10.7mm)
• Height: 0.29" (7.4mm) max.
• Weight: 1.6g (0.06oz)
• PCB thickness: 0.8mm

Documents:

sm�´l Power Board AAA Documentation:

• Schematic
• Eagle Files
• Hookup Guide
• GitHub Hardware Repo
• SparkFun smÃ�´l Power Board Arduino Library
• Arduino Examples

Boost Regulator:

• Datasheet (TPS61200)

Microcontroller:

• Datasheet (ATtiny43U)

sm�´l Documentation:

• smÃ�´l Hookup Guide