TLV61070A: Output abnormal

Hello, 

Update the circuit:

Connect pin 3 with pin6 to make EN voltage >1.2V acording to IC datasheet.

Add new question: 

Does the EN pin voltage > 1.2V, the IC start up? and IC output shutdown when EN voltage <0.4V?

Thanks. 

Hi Chambin,

Switching regulators are very sensitive to parasite inductance and there will be high risk that the device will damage if you use bread boards. Also, Cout without MLCC is strictly forbidden. Please apply for an EVM if you need to evaluate the IC and do not use bread board again.

Best Regards,

Travis

Hi Travis,

Thanks for your advice.

Can I use VIN to control IC strat up and shutdown when input voltage from 2v to 3v? 

Does the IC enable voltage > 1.2V and IC shutdown voltage <0.35V?

if enable/disable logic above is right , I have to give up this solution for I don't have anothe control signal line.

If I want to meet input 2-3 V, output 5V/1A,  when input lower 2V, IC will auto shutdown, use VIN(input pin) to control IC startup and shutdown.

could you give me another solution?

Thanks.

hello 

Do you think TPS61027 is a solution can meet our requirement?

Can I use TPS61020EVM board to test TPS61027 as follow change:

Remove R3 and R4, change R1 value to control IC ON/OFF, EN=VIN, PS=GND.

Could you help check may modification.

Thanks.

Thanks.

Hi Chambin,

You can use UVLO function to shut down the part, but UVLO threshold for TLV61070 is 0.5V instead of 2V. If you just need to test the EN function, you can use the JP1 to enable/disable IC:

Best Regards,

Travis

About TPS61027, the current limit is not enough for your condition. Actually TLV61070A also cannot output 1A under 1.8-5V condition:

So I'll recommend TPS61023.

Best Regards,

Travis

Hi Travis,

For TPS61023, is there alos need a signal to control EN or UVLO to shutdown the IC if voltage lower than 2V? if yes, we don't have extra pin to use this solution.

For TPS61027, could you help confirm this IC can meet input 2V, output 4.2V/0.5A?

or what else solution?

Thanks.

Hi Chambin,

If you need the device to be disabled when Vin <2V, then you'll need other Voltage monitor IC. Divider for ENpin may not be effective because of the hysteresis of EN-pin. 

TPS61027 will work for your condition.

Best Regards,

Travis

Hi Travis,

Very thanks for your advice.

I recieved EOL information from TI that TPS61032 will EOL, do you think TPS61030 is a good replacement solution has less modification?

only add two feedback resistors to TPS61030 FB pin to meed 5V output.

is there any difference between TPS61032 and TPS61030 except TPS61030 output voltage adjustable?

Thanks.