The LM317 IC is a reliable regulator with typical line regulation of 0.01% and load regulation of 0.1%. It also has internal short-circuit current limiting and thermal overload protection.
The circuit regulates voltage by turning all input/output difference into heat (effectively dissipating all the excess power). If it gets too hot it may damage the board or cause unexpected behaviour.
Because of that, the board’s operating range is defined by two factors. 1) maximum input voltage and current (should not exceed 20V/1A); and 2) maximum wattage arising from current and I/O voltage difference (should not exceed 2W, measured as I x (Input V - Output V).
The board also carries a MOSFET chip to toggle the output on and off.
VReg click communicates with the target board MCU through the SPI interface (CS, SCK, MISO, MOSI). The board can use either a 3.3V or a 5V power supply.
It is also possible to use the board’s power supply as the Input, by resoldering the onboard INPUT SEL jumper.
Type | Linear |
Applications | Regulating linear power supplies for a wide variety of devices |
On-board modules | LM317, MCP4921 12-bit DAC, MCP3204 12-bit ADC, ZXMP7A17K MOSFET, LMx58 Low-Power, Dual-Operational Amplifier |
Key Features | Input Output screw terminals |
Key Benefits | Digital control, Possible to use board’s power supply as input |
Interface | GPIO,SPI |
Input Voltage | 3.3V or 5V |
Compatibility | mikroBUS |
Click board size | L (57.15 x 25.4 mm) |
The following code snippet shows how to send temperature readings from VReg click to a TFT display.
1 while(1) 2 { 3 if(output < set_value) 4 { 5 value = value + 1; 6 if(value>4095) {value = 4095;} 7 } 8 9 if(output > set_value) 10 { 11 value = value - 1; 12 if(value<1) {value = 2;} 13 } 14 15 DAC_Output(value); 16 output = getADC(1)/1.82; 17 ProcessValue(output,2); // Writes measured value to Lcd 18 Delay_ms(10); // Wait 10ms 19 20 }
Code examples that demonstrate the usage of VReg click with MikroElektronika hardware, written for mikroC for ARM, AVR, dsPIC, FT90x, PIC and PIC32 are available on [Libstock].