1V voltage drop circuit

seven561

1V voltage drop circuit [Copy link]

I need to reduce the voltage from 5V to 4V, and the supply current changes from 80mA to 2A. Using a single diode, it is only 0.7V, but using two diodes, it is over 1.4V. Please help me how to achieve this without using DC-DC. Thank you!

seven561

Where are the big hands :)

liao026

Two diodes 1N4001 and 1N5819

qwqwqw2088

The 1V step-down voltage of the original poster is not so high. If you don’t mind the trouble, I recommend you TI’s LMR10520. The schematic diagram is for reference only!

dontium

As for 5V and 4V, the voltage difference is small, and the efficiency of using a switching power supply is not superior to that of an LDO; and the switching type is more expensive than an LDO, and has additional interference. Therefore, it is more appropriate to use an LDO. I think the original poster should open up other ideas, such as why it must be a 5V input and why it must be a 4V device.

seven561

DC-DC is not used due to cost considerations, and the voltage is also fixed because they are all modular devices. When the current increases, the diode voltage drop increases slightly, and basically remains at around 4.3-4.2. The module recommends a power supply of 4V, and the requirement is between 3.6-4.5, but there is a large overshoot at the moment of power-on, which can reach around 4.8V. The post-stage also has a large electrolytic

dontium

Is the GSM module used?

chunyang

Silicon tube series Schottky tube

仙猫

I don't know which of the following purposes is this? ①. I just want to reduce the power supply by 1V - if the power supply voltage changes from 5.2V to 4.8V due to the load, the output also changes from 4.2V to 3.8V. ②. I hope the output is stable at 4V. ③. The output is almost 4V, and the accuracy does not matter. If ③: It is the simplest to connect silicon diodes in series. If ②: Find a linear voltage regulator that can withstand more than 2A. If ①: It is also a linear step-down, but the reference point of the feedback is not to the ground, but to the power supply (see the picture).