AW3215A set cut-off current problem

void CHG_Done_Current_Set(void) 
{
    GPIO_PinModeSet(gpioPortC, CHG_CTRL_PIN, gpioModePushPull, 0);
    for(int itemp = 16; itemp > 1; itemp--); //延时5us左右
    GPIO_PinModeSet(gpioPortC, CHG_CTRL_PIN, gpioModePushPull, 1);
}

When you need to adjust the cut-off current, first look at the code and SEPC

The setting method in the code is as above,

SPEC sets the cut-off current as follows:

To know the cut-off current, you need to know Ioreg

Look at SPEC for Ioreg settings.

Ioreg = 100mV/Rsns

Look at Rsns and find the schematic diagram

This is the SNS resistor R505 0.1R_1% of the current B project, but I asked about the 0.13 resistor used in the BOM

Then 0.13.

So this Iorge = 0.100v/0.13Ω = 769mA.

This current seems to be relatively large.

According to the current code, the cut-off current of 20%Iorge = 0.2 * 769 = 153mA is used

The current requirement is to set to 300mA, then try

30% Iorge = 0.3 * 769 = 230.7mA

40% Iorge = 0.4 * 769 = 307.6mA

50%Iorge = 0.5 * 769 = 384.5mA

So setting 40% Iorge is more appropriate.

The current setting is to first pull the CTRL pin low and then delay 5us before pulling it low

First use an oscilloscope to verify whether the delay between pin low and high is "optimized" because it is not written as volatile.

First measure with an oscilloscope

First measured with Delay (20ms), it turned out to be 20ms. accurate

Try this loop again with the default code, there is a problem here, because it is not volatile, I verified that this loop does not work with the waveform

Change this int type to volatile uint32_t type, set it to 100*1000 cycles, use an oscilloscope 1S to capture the waveform, and measure

100*1000 cycles correspond to 42ms, which is 42*1000us, which means that 1 cycle corresponds to 0.42us.

The default code turns out to be 16 cycles

Then 16*0.42us = 6.72us

Although it is recommended in SPEC to set the high and low level time to 2us (1-10us), it is more appropriate, but I still modify it according to the cycle of the mode

All set to 6.72us delay

    /*
     * 100 * 1000 -> (shi)42ms --> 42* 1000us
     * 1->0.42us
     *
     */
    /*
     * 低6.72us--->高6.72us--->低6.72us--->高6.72us--->低6.72us--->高
     * 40%Ioreg
     */
    GPIO_PinModeSet(gpioPortC, CHG_CTRL_PIN, gpioModePushPull, 0);
	for(volatile uint32_t itemp = 16; itemp > 1; itemp--); //这个无所谓，默认的，是16*0.42 = 6.72us
	GPIO_PinModeSet(gpioPortC, CHG_CTRL_PIN, gpioModePushPull, 1);
	for(volatile uint32_t itemp = 16; itemp > 1; itemp--); //这个无所谓，默认的，是16*0.42 = 6.72us
	GPIO_PinModeSet(gpioPortC, CHG_CTRL_PIN, gpioModePushPull, 0);
	for(volatile uint32_t itemp = 16; itemp > 1; itemp--); //这个无所谓，默认的，是16*0.42 = 6.72us
	GPIO_PinModeSet(gpioPortC, CHG_CTRL_PIN, gpioModePushPull, 1);
	for(volatile uint32_t itemp = 16; itemp > 1; itemp--); //这个无所谓，默认的，是16*0.42 = 6.72us.
	GPIO_PinModeSet(gpioPortC, CHG_CTRL_PIN, gpioModePushPull, 0);
	for(volatile uint32_t itemp = 16; itemp > 1; itemp--); //这个无所谓，默认的，是16*0.42 = 6.72us
	GPIO_PinModeSet(gpioPortC, CHG_CTRL_PIN, gpioModePushPull, 1);

OK, write the theoretical code according to SPEC OK.

The official current can be verified.

1: To verify whether the normal charging current is 769mA.

2: To verify whether the cut-off current is 307mA

ps, you can actually test if the resistance of the SNS is 0.13Ω first, haha

Come to verify on Monday

AW3215A set cut-off current problem

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