4.4 Voltage Threshold Detector

The Microchip ATSAMA5D27-WLSOM1 embeds a MIC842 micro-power, precision-voltage comparator with an on-chip voltage reference.

The device is intended for voltage monitoring applications. External resistors are used to set the voltage monitor threshold. When the threshold is crossed, the outputs switch polarity. Refer to the figures below.

The MIC842 incorporates a voltage reference and comparator with fixed internal hysteresis; two external resistors are used to set the switching threshold voltage.

Supply current is extremely low (1.5 μA, typical), making it ideal for portable applications.

The MIC842 is supplied in 4-pin 1.2 mm × 1.6 mm Thin DFN package. For more information, refer to the product web page.

Figure 4-14. Voltage Threshold Detector Schematic
Figure 4-15. Voltage Threshold Detector Implementation Example
Table 4-4. Output Resistor Ladder Values and Input System Supply Example
System Supply Voltage Threshold Detection Value Rext1 Value Rext2 Value
5V 4.64V 787 kΩ 287 kΩ
12V 11V 787 kΩ 100 kΩ
24V 21.78V 787 kΩ 47.5 kΩ
48V 39.51V 787 kΩ 25.5 kΩ