TPS73625 chip test based on acceleration technology ST2500 (5)

Table of contents

Five, TPS73625 chip load adjustment rate test

1. Test principle

2. Test schematic diagram

3. Test steps

4. Test code

5. Test results

Five, TPS73625 chip load adjustment rate test

1. Test principle

When we choose a voltage regulator, we often pay attention to one of its important parameters, which is the load capacity, that is, the ability of the LDO to output the maximum current within a limited range of deviation between the actual output voltage and the theoretical output voltage. However, in reality, the greater the load, the greater the impact on the output of the LDO, as shown in the figure. The load regulation rate is used to characterize the ratio of the output voltage change (relative to the theoretical output voltage) caused by different /OUT. The smaller the load regulation rate of the LDO, the stronger the ability of the LDO to suppress load disturbance.

2. Test schematic diagram

3. Test steps

(2) Use PPMU resources to apply 2V to the EN pin

(3) Use the DPS resource to apply 3.5V to the IN pin

(4) Use the "FIMV" working mode of the BPMU to apply a -1mA current to the OUT pin to measure its voltage stMeasValue1

(5) Use the "FIMV" working mode of the BPMU to apply a -10mA current to the OUT pin to measure its voltage stMeasValue2

(6) Close K4 to select a 6.25Ω load, and measure the OUT pin voltage value stMeasValue3 at this time

(7) Calculate the maximum output current according to Ohm's law

(8) Calculation of load regulation

4. Test code

USER_CODE void LDR_TEST() {
	TEST_BEGIN

	// TODO Edit your code here
	//定义变量存储测试结果
	vector<ST_MEAS_RESULT> stMeasValue1,stMeasValue2,stMeasValue3;

	//使用PPMU资源给EN引脚提供2V电压
	ppmu.Signal("EN").SetMode("FVMI").VoltForce(2.0).CurrRange(40e-3).Execute();
	
	//使用DPS资源给IN引脚施加3.5V电压
	dps.Signal("IND").SetMode("FVMI").VoltForce(3.5).CurrRange(40e-3).CurrClamp(0.5, -0.5).Execute();
	
	//使用BPMU资源向OUT引脚施加-1mA电流并测量输出电压
	bpmu.Signal("OUTB").SetMode("FIMV").CurrForce(-1.0e-3).CurrRange(2.5e-3).Clamp(6.5, -2.0).Execute();

	//测量OUT引脚电压值
	sys.DelayUs(1000); 
	bpmu.Signal("OUTB").Measure(stMeasValue1);
	
	//使用BPMU资源向OUT引脚施加-10mA电流并测量输出电压
	bpmu.Signal("OUTB").SetMode("FIMV").CurrForce(-10.0e-3).CurrRange(40e-3).Clamp(6.5, -2.0).Execute();
	
	//测量此时OUT引脚的电压值
	sys.DelayUs(1000);
	bpmu.Signal("OUTB").Measure(stMeasValue2);
	
	//复位
	bpmu.Signal("OUTB").SetMode("FIMV").CurrForce(0.0).Execute();
	bpmu.Signal("OUTB").SetMode("FNMV").Execute();
	sys.DelayUs(10000);
	
	//闭合K4选择6.25Ω负载
	cbit.Signal("K4").SetOn();
	sys.DelayUs(8000);
	
	//测量此时OUT引脚电压
	bpmu.Signal("OUTB").Measure(stMeasValue3);
	
	//计算最大输出电流
	double IMAX = stMeasValue3[0].dbValue / 6.25*1000;
	
	//计算负载调整率
	stMeasValue1[0].dbValue = ((stMeasValue3[0].dbValue - stMeasValue1[0].dbValue)/(stMeasValue1[0].dbValue*IMAX))*100;
	stMeasValue2[0].dbValue = ((stMeasValue3[0].dbValue - stMeasValue2[0].dbValue)/(stMeasValue2[0].dbValue*IMAX))*100;

	//对计算的结果进行分BIN操作
	binObj.CheckResultAndBin(0, stMeasValue1, 1);
	binObj.CheckResultAndBin(1, stMeasValue2, 1);

	//对EN，IN引脚进行复位
	dps.Signal("IND").SetMode("FVMI").VoltForce(0.0).Execute();
	dps.Signal("IND").SetMode("FNMV").Execute();

	ppmu.Signal("EN").SetMode("FVMI").VoltForce(0.0).Execute();
	ppmu.Signal("EN").SetMode("FNMV").Execute();
	sys.DelayUs(10000);

	//闭合K4
	cbit.Signal("K4").SetOff();
	sys.DelayUs(8000);
	
	TEST_ERROR
	binObj.HandlerException(0);
	TEST_END
}