Accurate digital power monitor offers wide common mode input voltage range

July 21, 2014 // By Graham Prophet
Intersil’s ISL2802x family of digital power monitors supports a wide common mode input voltage range of 0V to 60V. Three devices offer a range of capabilities including full featured bi-directional, high-side and low-side digital current sense and voltage monitors with a serial interface with a high level of integration.

Precision measurements are enabled by an integrated 16-bit ADC. Available in a tiny solution footprint and with a wide specified temperature range, the ISL2802x digital power monitor family is suitable for telecom, industrial and consumer applications.

Current, voltage and power measurements can be implemented with basic op amps and current sense amplifiers, but require complicated analogue design while providing limited real-time system information. ISL2802x digital power monitors integrate many common electronic building blocks resulting in system designs that have reduced complexity without compromising performance.

The ISL2802x family consists of the three variants; ISL28023 is a full featured PMBus compatible digital power monitor that integrates the analogue comparators, a voltage regulator, a DAC and a low voltage auxiliary channel in a single chip. ISL28025 is a high precision digital power monitor with integrated analogue comparators and an integrated voltage regulator. The integrated analogue comparators for the ISL28023/5 allow for continuous monitoring of the inputs. This results in a very fast response time (500 nsec) enabling real-time alerts for rapid system shut off if necessary. The ISL28022 is a highly efficient digital power monitor suitable for cost-constrained applications.

The ISL2802x family delivers high accuracy measurements through an integrated 16-bit native resolution sigma-delta ADC (gain error = ± 0.05% Typ) 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. Specified temperature range from -40ºC to 125ºC provides greater design flexibility.

The chips;

• Monitor supply voltages up to 60V

• Have digital output via serial interface that is I2C, SMBus and PMBus compatible and have;

• I2C that operates down to 1.2V

• Operating voltages from 3V to 5.5V and consuming an average current of 800 µA

• User defined threshold alerts (OV,OC,UV)

• Integrated 8-bit voltage output margin DAC

• Internal 3.3V voltage regulator

• Auxiliary channel for monitoring current