I wish to do LED driver with TPS40211.
Vin = 12V or 24V
Vout = 100V
ILED = 150Ma
Switching frequency >200KHz.
DCM Boost converter
I wish to be able to flash the LEDs on and off at 25Hz (50% duty cycle).,
I do not want any LED current or inductor current overshooting when the LEDs are flashing back on again.
I notice that TPS40211 has a disable pin……if the part is re-enabled, does the soft start happen again?...or does soft start only happen at initial application of input power?
Also, when re-enabled, how long does the chip take to start-up again,? Is it a long time.
Also, is it OK to flash the LEDs on and off by repeatedly enabling/disabling the TPS40211?
well, EN doesn't acts like a PWM/DIMM function...
it is even true that because the very low freuqency, the SS time could be neglected (since the overall effect would be "averaged")
if you need a real dimming feature then you could have a look at the TPS61196 (still in preview) at the link http://www.ti.com/product/tps61196
another possibility would be to use an external fet for dimming the current into the led (have a look at EVM of LM3409HV, for details)
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