Renesas' robust and highly accurate digital power monitor (DPM) family offers high level of integration and a range of capability including high common mode voltage support, full featured bidirectional, high-side and low-side digital current sense and voltage monitors with fast interrupts and serial interface.
Renesas' ISL2802x digital power monitor family delivers high accuracy measurements in a wide input common mode voltage range (0V to 60V), providing designers with a high level of safety margin that is often necessary in wired, wireless and data infrastructure applications.
The ISL2802x family is comprised of three devices offering a range of capability including full featured bidirectional, high-side and low-side digital current sense and voltage monitors:
- ISL28022 is a bidirectional high-side and low-side digital current sense and voltage monitor with serial interface.
- ISL28023 is a precision DPM that integrates the analog comparators, a voltage regulator, a DAC and a low voltage auxiliary channel in a single chip.
- ISL28025 is a high precision DPM with integrated analog comparators and an integrated voltage regulator.
Available in a tiny solution footprint and with a wide specified temperature range, the ISL2802x digital power monitor family is ideal for telecom, industrial and consumer applications.
We also offer industrial battery management systems for > 3 cell solutions.
What are Digital Power Monitors
Digital power monitors are integrated solutions that provide high-side, low-side, and bidirectional current monitoring, as well as voltage monitoring, and use an on board ADC to provide digital feedback.
Digital power monitors can be used with a battery, DC motor or the loading of the circuit. Knowing the amount of current flow is important for performing such features as:
- battery charging,
- motor speed control or
- short circuit detection.
Amplifiers are used in applications to measure the amount of current flow through a circuit. An amplifier is used to amplify the voltage developed by the current sense so it can properly drive the ADC.
Digital power monitors integrates the amplifier and ADC into a single IC to measure both current and voltage and now provides digital output to the microcontroller or FPGA.
Digital Power Monitor Applications
A primary application for a DPM is to measure current, voltage, and power in a power system. The 0 to 60V input voltage range works well in circuit breaker and system health applications.
In the example circuit, a principal ISL28025 monitors the regulated 12V to 60V line that feeds several power subsystems, and additional ISL28025 devices are used to monitor a lower regulated voltage and individual loads.
Power modules are also added to the circuit for high current point of load applications.The ISL28023 and the ISL28025 follow the PMBus industry standard protocol, simplifying the coding required for communication.
The SMBAlert line provides quick feedback if a threshold is crossed, indicating a problem in the circuit and allowing easy identification of the problem area. A second SMBAlert line is also used to shut down the main power through analog components for an even faster response time.
For more application design ideas, see AN1955: Design Ideas for Digital Power Monitors.
Renesas provides a complete portfolio for power monitor and current sensing solutions: