TPS61070: TPS61070 minimum on time

Lin_Charles

Part Number: TPS61070

Hi team,

I am using TPS61070 as below, Io=100mA. Could you please help review the schematic if we have any risk on below application?

BTW, I cannot find the minimum on time of our device, could you please help provide this spec? Thanks.

over 5 years ago

0 Minqiu Xie over 5 years ago

TI__Mastermind 21565 points

Hi Charles:
I'm sorry that I have no data of min Ton in hand. I'll check with my team.
For the circuit:
1. How does the system Pull Up/ Down the EN? Does customer care about the power loss when the socket disable?
2. Does it startup with 100mA load？ If it does, the startup may fail.

0 Lin_Charles over 5 years ago in reply to Minqiu Xie

TI__Expert 4260 points

Minqiu, thank you for your help here. For your question, please see my response below,
1. When EN=3.3V, the system will power up. Else the EN=0. They want to use EN to control our device.
2. What do you mean by saying star up will fail?

0 Minqiu Xie over 5 years ago in reply to Lin_Charles

TI__Mastermind 21565 points

Hi Charles:
1. Please realize there will be a little additional power loss caused by R60 when EN=0, VIN=high.
2. The current limit during startup is different between normal operation. The details is in 10.3.1.4 of datasheet. and the Figure 11. shows the typical relationship. It's recommended to load after startup.

0 Lin_Charles over 5 years ago in reply to Minqiu Xie

TI__Expert 4260 points

Hi Minqiu. thank you for your help here. We use this device as load after the startup. I am not sure if this device can be used in such low on time (duty cycle is 5.7%)??. Could you please help share us the minimum on time of this device? Thanks.

0 Minqiu Xie over 5 years ago in reply to Lin_Charles

TI__Mastermind 21565 points

Hi Charles:
I has limited data in my hand for TPS61070.
What's the needs of VOUT? should it be accurate 3.5V? TPS61070 has power save mode. In this mode, the vout may a litter higher than target.
The minimum on time won't be a problem if the power save mode could be accepted.

0 Lin_Charles over 5 years ago in reply to Minqiu Xie

TI__Expert 4260 points

Hi Minqiu. Please help check the output voltage requirement:
Vout：3.5V±10%，Io：Max 200mA，Avg<100mA.Please help check if we can support this spec. Thanks.

0 Minqiu Xie over 5 years ago in reply to Lin_Charles

TI__Mastermind 21565 points

Hi Charles:
This requirement seems safe if startup without load.
I have done a bench test before based VIN=3V, Vout=3.3V, 250mA similar with yours.

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TPS61070: TPS61070 minimum on time