TPS61196 minimum dimming frequency

Michael Fraimovich

Other Parts Discussed in Thread: TPS61196

Hi,

Question regarding TPS61196 LED driver: Although 90 Hz minimum PWM dimming frequency is indicated in the datasheet, how lower frequency will affect the driver behaviour (while minimum pulse width kept above 50usec)? I'm interested in using dimming PWM frequency down to 24Hz.

Thanks!

Michael

over 9 years ago

0 Nisha Patel over 9 years ago

TI__Intellectual 1055 points

Hi Michael,

We do not recommend using a PWM frequency lower than 90Hz.

Thanks,

Nisha

0 Michael Fraimovich over 9 years ago in reply to Nisha Patel

Prodigy 170 points

Hi Nisha,
Thank you for the reply.
Please help me with another question: How will LED driver respond to resistive or capacitive load?
It must be my lack of knowledge in current supplies. Please help.

Thanks,
Michael

0 Nisha Patel over 9 years ago in reply to Michael Fraimovich

TI__Intellectual 1055 points

Hi Michael,

There is a current sink at the IFB pins that delivers current to the load the value of the current is set by the Iset resistor. The output voltage is adaptive and constantly adjusts based on the load.

Thanks,

Nisha

0 Michael Fraimovich over 9 years ago in reply to Nisha Patel

Prodigy 170 points

Hi Nisha,

Thanks for your previous response. Got two more questions: The spec says 50mA is the minimum current the driver can be preset to.

1. How the driver will respond to lower current setting, 20mA for instance?

2. Can I change the current setting dynamically, throughout the operation, with a load connected? If yes, how fast the device will respond, and how fast the setting may be changed? Is there any other limitation for that kind of change?

Thanks!

Michael

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TPS61196 minimum dimming frequency