2012년 4월 27일 금요일

TI E2E - [TPS659110] how to power up the TPS659110 without PWRON low-to high trigger input...?

TI E2E - [TPS659110] how to power up the TPS659110 without PWRON low-to high trigger input...?

Hello~

I have a question or clarification...

According to "Figure 3. Device State Control Through PWRON Signal" & some pages which is included the "Figure 12. Embedded Power Control State-Machine" in the TPS659110 datasheet, it seems that TPS659110 needs low-to-high trigger input on the PWRON pin to initiates the power up the device properly...

But, I want to initiates the power up the device just by the ramp up of Power Supply's output voltage, without low-to-high trigger input on the PWRON pin...

In other words, I would like the power up to be initiated by power supply's output voltage (5.0V) ramp up and power down to be initiated by Power Supply off...

Do you have some solutions or tips for this kind of issue...?

Thanks... C.W. :)

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Dear Chang-woo YANG,

Power up can be initiated by the rise of Input voltage (Vcc7): please refer to Figure 6 "Device Turn-On/Off with Rising/Falling Input Voltage" p34.

Regarding power down:

if the device is in ACTIVE state and Vcc7VMBHI, the device will go to OFF state (see Figure 12)

If you want to switch off the device (from ACTIVE to OFF state), you need to disable Power on. To do it, you can, for instance, use PWRDN.

In order to switch off the device with respect to the battery voltage, you can monitor the interrupts relative to battery voltage for instance VMBDCH2. Then you can decide to set PWRDN to the right level (according to its polarity defined in PWRDN_POL) to switch off the device according to the battery voltage.

Hope this helps,

Best regards,

Flore

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