“This is a multiple output power converter module that provides +/-10V (Dual 10V), 5V DC, and 3.3V DC from a 9V PP3 battery. This is a very useful project that has been designed for low-load current applications. Dual +/-10V output from a 9V battery is a key feature of the project. The battery holder can be mounted on the backside of the PCB. An onboard slide switch provides power ON/OFF. Onboard LED indicates the power. LM1117-5V chip provides 5V DC output from 9V Battery, further, an LM1117-3.3V regulator is provided to step down the 5V to 3.3V DC. MAX680 charge pump chip provides +/-10V from 5V.
The MAX680 is a monolithic, CMOS, dual charge-pump voltage converter that provides ±10V outputs from a +5V input voltage. The MAX680 provides both a positive step-up charge pump to develop +10V from +5V input and an inverting charge pump to generate the -10V output. This chip has an on-chip, 8kHz oscillator. The output source impedances are typically 150Ω, providing useful output currents up to 10mA. The low quiescent current and high efficiency make this device suitable for a variety of applications that need both positive and negative voltages generated from a single supply.”