Adafruit LM66200 Ideal Dual Diodes Breakout

Most projects these days have multiple power supplies: say a battery or DC wall plug or USB for multiple powering options. Juggling these to have seamless hot-swap while avoiding back-powering is always a bit of a challenge: you want to keep things small, cheap, low power and of course reduce as much voltage drop as possible.

The Adafruit LM66200 Dual Ideal Diode breakout is a cute solution to dual supplies: it has back-voltage protection, and two ‘ideal’ diodes with RdsOn of 40 milliohms, support for 2.5A continuous draw and a separate enable input and status output.

Sure you could DIY the circuitry with multiple transistors, but this is compact and easy to use! Simply connect the two 2~5V power supplies to Vin1 and Vin2, the higher of the two will appear on Vout. Disable the output completely by pulling the On/Enable pin high. Check the Status pin, if desired, to see whether Vin1 or Vin2 is the selected supply.

To make it breadboard-friendly, we’ve placed it on a small PCB with 6 x 0.1′ breakout pads. The chip and a 1 Megaohm enable-pulldown are soldered on top. We include a bit of header, some light soldering is required to attach the header – or use free wiring if you want to insert it directly into a circuit.

Specifications

• LM66200 Product information page
• Input voltage range: 1.6 V to 5.5 V
• Maximum continuous current: 2.5 A
• On-resistance: 40 mΩ (typical)
• Standby current: 50 nA (typical)
• Quiescent current: 1.32 μA (typical)
• Automatic diode switchover
• Controlled output slew rate: 1.3 ms (typical) at 3.3 V
• Reverse current blocking when VOUT > VINx
• Thermal shutdown
• Dimensions: 16.5mm x 10.0mm x 2.2mm
• Weight: 0.5g