Other Parts Discussed in Thread: TPS92641
Tool/software:
TPS92641EVM: A Test report
This is a report on a modulation experiment carried out with the TPS92641EVM evaluation board.
Aim: To modulate LEDs up to 1MHz with a 50%duty cycle. The voltage was measured between TP10(SW) and the ground and seen on an oscilloscope. A MOSFET (IRF540N) was connected at Q3
Quick summary of results: Even At 10Khz and above, the voltage is not a square wave with a 50%duty cycle
Here are the results at various frequencies
Testing condition:
Power supply at 43V
Signal generator @ 2.5V
Yellow: signal generator connected to udim
Blue: voltage Across TP10(SW) and ground
.
100KHz 10Khz
Voltage between LED+ and ground,
Yellow: function gen. Blue: Signal
1KHz 10KHz
50kHz 100Khz
Beyond 1 KHz, the voltage across the LED is not a square pulse with a duty cycle of 50%. We are unable to modulate the LEDS with a square wave. We need to modulate the LED to 1MHz. Please help
The PDF of this report is attached here.
