TPS61288: Maximum continuous current support

external nikhil

Part Number: TPS61288
Other Parts Discussed in Thread: TPS552892, TPS552882

Tool/software:

Hello

I would like to use TPS61288 boost for my system which is battery operated with 3 cells. Below are the requirement specifications.

Vin_min = 10V and Vin_Max = 15V.

Vout = 15V and Iout = 4A.

for this requirement TPS61288 will it support. if yes what are the design constraints has to be considered for 4A continuous current.

11 months ago

0 Fergus He 11 months ago

TI__Genius 16325 points

Hi nikhil,

TPS61288 is not suitable to work at Vin=15 to Vout=15V.

The device has a limitation on switch on-time so that when working in such condition, the output will be in large ripple and system is unstable.

The max input voltage is recommended to below 14.5V to ensure a stable working.

As far as I know, the max voltage of a li-battery is 4.2V and 3 cells would be 12.6V.

The device is capable of the condition that Vin=10V to 12.6V and VO=15V Io=4A.

Please see the attached calculation tool for the design.

7077.TPS61288 Calculation tool.xlsx

Best Regards,

Fergus

0 external nikhil 11 months ago in reply to Fergus He

Prodigy 30 points

Hello Fergus, He,

Thank you for your input. Now it is clear that TPS61288 will not suitable for my application.

we have primary supply from SMPS with 15V DC output and as a secondary supply is 3 cells connected to the same power rail as backup when there is no output from SMPS.

can you please suggest any other boost for my requirement with design calculations.

0 Fergus He 11 months ago in reply to external nikhil

TI__Genius 16325 points

Hi nikhil,

For 15V to 15V application, a BUCK-BOOST converter is advised.

TPS552892 36-V, 8-A, Fully Integrated Buck-boost Converter datasheet (Rev. A)

I will forward to my colleges to answer any questions about this device.

Best Regards,

Fergus

0 external nikhil 11 months ago in reply to Fergus He

Prodigy 30 points

will this part support for continuous current of 5A at 15V.

0 Mulin Yuan 11 months ago in reply to external nikhil

TI__Genius 15400 points

Hi nikhil,

For application that Vin=10-15V, output 15V/4A, maximum average inductor current is about 15*4/0.95/10=6.3A. Minimum average inductor current limit for TPS552892 is 7A, so it is suitable.

For application that Vin=10-15V, output 15V/5A, maximum average inductor current is about 15*5/0.95/10=7.8A, this is out of TPS552892 spec. In this case I will recommend TPS552882, which is a 16A part.

Regards,

Mulin

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TPS61288: Maximum continuous current support