Importance of Monitor Power Supply Voltage
In equipment, especially those powered by batteries, monitor the power supply voltage becomes essential. For devices reliant on batteries, fluctuations in input voltage provide valuable insights into the remaining energy. Even devices connected to mains power can benefit from monitoring various power supply voltages within the circuit, allowing for prompt action in case of faults or irregularities. To handle these situations intelligently, integrating a microcontroller seems like a logical step. The microcontroller can periodically assess voltages using one or more A/D converters, making decisions based on these readings. While this approach offers intelligence, it does come at a cost, requiring processor time and adding complexity to the firmware. Balancing these additional tasks becomes challenging, especially when there are other functions that need regular attention.
Maxim’s Specialized ICs for Voltage Monitoring
Maxim, the chip manufacturer, offers a range of ICs designed specifically for voltage monitoring purposes. These ICs are programmed to monitor multiple voltages, generating an interrupt when these voltages deviate from specific requirements. For instance, the MAX1153 and MAX1154 come equipped with a 10-bit ADC, while the MAX1253 and MAX1254 feature a 12-bit ADC. These ICs possess the capability to monitor 8 external voltages and 2 internal voltages, ensuring comprehensive monitoring capabilities.
Versatile Configuration for External Voltages and Temperature Sensors
The 8 external voltages can be easily reconfigured for temperature sensors. Using an external diode as a cost-effective sensor, each channel can specify maximum and minimum voltage or temperature thresholds. Whenever the input voltage or temperature strays beyond these limits, the interrupt output activates. Additionally, individual glitch suppressors can be configured for each channel. The ICs offer a recursive averaging filter, allowing users to define the number of successive samples required outside the range before triggering the interrupt. Moreover, the ADC’s sample rate is adjustable, reaching a maximum of 90 samples per second. Communication with the controller occurs through the SPI bus, requiring just four signals for seamless interaction.