Hi
I just realized 2 issues in my design. I output a PWM signal as GSCLK from a ATMEL 33 Mhz Xmega. I have 20 TLC = 320 LEDS on my board.
Problem 1: my LEDs glow a tiny bit. I just see them in a dark room. Here only GSCLK is generated and DC/Gs data have not been set yet. So in theory LEDs should be OFF totally. GSCLK frequency is around 8 Mhz. When I decrease the GSCLK to 400 Khz, the LEDs go off completely. However i see a short intesive flash every 4-10 seconds. The flash happens across the board for all LEDS. Any idea what is going wrong?
Problem 2: As said before I generate GSCLK as PWM. Beyond 8 Mhz (like 12 or 16 MHz) some TLC shot off the LEDS. Like at 12 Mhz 16 channels of one TLC are all off. In this case I have already sent out GS , DC data and the BLANK bit, and My LEDS would work as expected with 8 Mhz, but not with 12 MHz.
On my HW design I have no terminal resistors for GSCLK line which drives all 20 TLCs. Is that the issue?
Thx