TPS61178EVM-792: Configuring the EVM to operate at input voltages 3V - 4.2V

Nabil M

Part Number: TPS61178EVM-792
Other Parts Discussed in Thread: TPS61178, TPS61089, TPS61088

Hi,

So I have here the EVM for the TPS61178. The device is rated to handle voltages as low as 2.7V but the EVM is optimized for

inputs 5V to 12V and a fixed output of 16V.

I changed the feedback resistor Rupper value from 1000k to 600k, to get the output voltage to be around 10.2V.

I'm working with a lithium ion battery rated at 3.7V nominal, 2400mA. I will pull at max around 0.7A - 1A from the battery. The load

is a class-D amplifier connected to two speakers ( 8 ohms each), so the current draw will be very dynamic.

Is it okay for me to work with a voltage this low for this EVM (3V to 4V) ?

Thanks,

Nabil

over 6 years ago

0 Jasper Li over 6 years ago

TI__Mastermind 46905 points

yes. the EVM works for the condition you mentioned.

btw, why not TPS61088 or TPS61089 if only 10V output voltage

0 Nabil M over 6 years ago in reply to Jasper Li

TI__Intellectual 1840 points

It seems to work fine but the output voltage dips down to 6-8V at heavy loads. Is this because the compensation network and output filter design isn't suitable for this configuration ?

Well I needed anything from 7V to 14V output and this IC seemed suitable for the job, although I hoped the EVM had an adjustable output.

0 Jasper Li over 6 years ago in reply to Nabil M

TI__Mastermind 46905 points

what is output current in the heavy load? could you measure of the VIN, VOUT waveform of your observation?

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TPS61178EVM-792: Configuring the EVM to operate at input voltages 3V - 4.2V