This module adopts TI lifting voltage special chip TPS63020 lifting voltage program, the output ripple is low, stable performance, switching frequency is up to 2.4MHZ, the majority of cases of the output current is 900ma, for the power supply occasions, the same module The module also has two modes for users to choose: normal operation mode and power saving mode. The module is a typical step-up/down structure, with input voltage range of 1.8-5.5V, which can meet the power supply requirements of STM32, ESP32, 51 microcontrollers and other models. The module contains a red LED output indicator, and supports power-saving modes to increase the battery life of the input devices. Color: Black Material: PCB + electronic components Input Voltage: DC 1.8-5.5V Output Current: 4.2V@1A Output Voltage: DC 4.2V Switching Frequency: . 2.4MHZ Regulation: 4.2V Module interface: large area pad (2.54mm pin) Package Contents: 2 x Automatic Boost Buck Step Up Down Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.