I'm planning to drive two white leds like these (datasheet) with PAM2803 driver (datasheet) and a single cell lipo battery.
Before ordering a pcb, I'm testing on a breakout board. With a 0.13 Ohm shunt resistor, I'm expecting a 730mA current. As test load, I'm using a 2 Ohm resistor (5x10 Ohm in parallel). The result should be 1.46V on the resistor.
From the sheet, the device should be powered between 0.9v and "forward voltage of the led - 0.2v"
I'm powering the test system with 1V which is between 0.9 and 1.46-0.2 = 1.26v.
I'm using a 2.4 µH inductance (FDSD0420-H-4R7M=P3 : datasheet) and MBRA210LT3G schottky (datasheet).
The result is not the one expected: resistor voltage is 690mV thus 345mA. If I increase the input voltage, the current increases too. What's wrong?
Here's a picture of the board. It's not easy to see on it. Shunt resistor is soldiered just between the pins. Capacitors are on top of their tracks.