The SMM151/152 are highly accurate power supply voltage/current supervisors and monitors with provisions for voltage margining of the monitored supply. The parts include an internal voltage reference to accurately monitor and margin the supply to within 1%. The SMM151/152 have the capability to margin over a wide range from 0.3V to VDD using the internal reference and can read the differential voltage of the supply and voltage drop of the current sense resistor over the I2C bus using an on-chip 10-bit ADC. The margin levels are set using the I2C serial bus. The devices initiate margining via the 2