Other Parts Discussed in Thread: TPS65381-Q1
Hi Dear TI team,
We have a question on "TPS65381AQDAPTQ1".
We are using the datasheet tps65381a-q1.pdf (SLVSDJ1A –JULY 2016–REVISED MAY 2017).
How to use "TPS65381AQDAPTQ1"
In our Equipment, the voltage is applied from the battery to the VBATP pin of the TPS65381AQDAPTQ1.
Voltage is applied to the VBATP pin of the TPS65381AQDAPTQ1 until the battery is empty.
[Circuit configuration]
The momentary power switch (which becomes Hi when pressed) is connected to the following IC terminals.
TPS65381AQDAPTQ1: CANWU pin
TMS5704357BZWTQQ1: GIOA6/N2HET2_4/EPWM1B pin
When the power switch is pressed, the Equipment is turned on by the Lo→Hi→Lo pulse of the TPS65381AQDAPTQ1: CANWU pin
.
To turn off the Equipment, the TMS5704357BZWTQQ1: GIOA6/N2HET2_4/EPWM1B pin Lo→Hi pulse is detected to turn the device off by pressing the same power switch, and the device is turned off.
After that, it detects that the GIOA6/N2HET2_4/EPWM1B pin has changed from Hi to Lo, and executes the "WR_CAN_STBY command" to the TPS65381AQDAPTQ1 to turn off the power to the TMS5704357BZWTQQ1.
【phenomenon】
"I pressed the power switch to turn off the Equipment, and then pressed the power switch again to turn on the Equipment without any delay, but the Equipment did not start."
Question 1
P.21 of the data sheet Sentence described in "NOTE"
"The WR_CAN_STBY command should not be written to the device while the CANWU pin or IGN pin is still high"
Our understanding is "Do not execute the WR_CAN_STBY command when the CANWU pin is Hi. ”.
If the "WR_CAN_STBY command" is executed when the "CANWU pin" is Hi, what state will the TPS65381AQDAPTQ1 enter in Figure 5-16 on page 65 of the data sheet?
Question 2
If the "WR_CAN_STBY command" is executed when the "CANWU pin" is Hi and it does not go into the "STANBY" state, please tell me how to return the TPS65381AQDAPTQ1 to the normal state.
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reference
There is a similar question on the E2E forum URL below.
(1) TPS65381-Q1 Power down by CANWU event - Automotive Forum (Read-Only) - Automotive (Read-Only) - TI E2E support forums
Answer:
A2) If CANWU goes high again while or just after WR_CAN_STBY command is written there is a risk the TPS65381 will not go through its power on reset state.
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Our question:
"power on reset state." in the answer is not shown in Figure 5-16 on page 65 of the datasheet.
What kind of state is "power on reset state."?
Best Regards
Kobayashi/HITACHI KOKUSAI Electric Inc.
