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 VoltageThreshold Detection ValueRext1 ValueRext2 Value
5V4.64V787 kΩ287 kΩ
12V11V787 kΩ100 kΩ
24V21.78V787 kΩ47.5 kΩ
48V39.51V787 kΩ25.5 kΩ