Review/Test of 1A 2.7-5.5V Buck-Boost Circuit board





Driver is from Intl-outdoor.com

Official specifications:

• Input voltage: 2.7-5.5V
• Buck-Boost driver
• Constant current output, 1A (To the LED)
• This driver does not use PWM
• High mode efficiency from 84% to 90% depending on the input voltage.
• Medium mode efficiency 94-95%
• Memory function
• Low voltage protection
• Reverse polarity protection
• First PCB Diameter: 15mm
• Second PCB Diameter: 16.6mm
• Total height: 6.5mm
• Gold plated contacts
• Tinned copper leads

Low voltage protection system:
*If the battery voltage is lower than 3V:
when the light is on (constant light), the output will be changed to 10mA.
when the light is flashing , the output will be changed to 50mA and keep flashing.
*If the battery voltage is lower than 2.7V, the output will be cut off but still there will be an input of about 0.3mA
(There will be no current consumption switching the flashlight off )



Measurements

Tested with: Cree XP-G2
Max. height: 6.5mm
Diameter: 16.5 mm and 15mm.
Strobe: 10Hz at 3.7 volt.
The driver has high, medium, low, strobe and sos.
The driver has memory, the actual mode is stored when the light is off for a short time.
A very short off/on will select next mode.
The driver is mainly buck, but can boost a little bit.



High



The drop in led current between 3.25 volt and 3.50 volt is probably the change from buck to boost.






Very good regulation, without any noise.



Medium



Due to inherited looses in the circuit, the boost need to be activate while the input voltage is above the Vf of the led.






Low



At low the boost is not needed and due to the low current there is some noise in the measurements.






Strobe





SOS



The spacing in the morse code is not correct.



Conclusion

This driver will provide full output from 3.0 volt to 5.5 volt with good efficiency.
I like this driver.



Notes

How do I test a led driver
List of all tested drivers