电流消耗
计算公式I i n = I Q v i n + V o u t V i n ∗ η 1 ∗ ( I Q v o u t + I f b + I l o a d ) I_{in}=I_{Qvin}+\frac{V_{out}}{V_{in}*η_{1}}*(I_{Qvout}+I_{fb}+I_{load})Iin=IQvin+Vin∗η1Vout∗(IQvout+Ifb+Iload) - I Q v i n I_{Qvin}IQvin is the I q I_{q}Iq into the V i n V_{in}Vin pin
- V o u t V_{out}Vout is the output voltage of the boost converter
- V i n V_{in}Vin is the input voltage of the boost converter, or the battery voltage
- η 1 η_{1}η1 is the efficiency when the boost converter is switching
- I Q v o u t I_{Qvout}IQvout is the I q I_{q}Iq into the v o u t voutvout pin
- I f b I_{fb}Ifb is the current of the feedback resistor divider
- I l o a d I_{load}Iload is the load current
V i n V_{in}Vin和V o u t V_{out}Vout都是已知的,空载时I l o a d I_{load}Iload为0,I f b I_{fb}Ifb为输出电压除以两个反馈电阻之和,BOOST的效率一般较高,可以选择85%~90% I Q v i n I_{Qvin}IQvin和I Q v o u t I_{Qvout}IQvout一般DC-DC的SPEC中会给出。
TI实际测试值和公式计算值进行对比,还是非常接近的。
为什么用公式计算空载时输入电流,因为一般这个值非常小,实际测试会有很大的机器误差,需要使用精密的电流源
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