• Monitors four DC voltages and the AC line
• Precision 2.5V ±1% low-drift reference
• Fault tolerance adjustable from ±5% to ±40%
• ±3% trip threshold tolerance over temperature
• Separate 10mA, 40V overvoltage, undervoltage and AC line fault outputs
• Fault delay programmable with a single capacitor
• 30mV comparator hysteresis to prevent oscillations
• On-chip inverting op amp for negative voltage
• Open-collector output logic or expandability
• Operation from 4.5V to 40V supply

The SG1548 is an integrated circuit capable of monitoring up to four positive DC supply voltages simultaneously for overvoltage and undervoltage fault conditions. An on-chip inverting op amp also allows monitoring one negative DC voltage. The fault tolerance window is accurately programmable from ±5% to ±40% using a simple divider network on the 2.5V reference. A single external capacitor sets the fault indication delay, eliminating false outputs due to switching noise, logic transition current spikes, and short-term AC line interruptions. An additional comparator referenced to 2.5V allows the AC line to be monitored for undervoltage conditions or for generation of a line clock. The comparator can also be used for programmable undervoltage lockout in a switching power supply. Uncommitted collector and emitter outputs permit both inverting and non-inverting operation. External availability of the precision 2.5V reference and open-collector logic outputs permit expansion to monitor additional voltage using available open-collector quad comparators.

Microchip Ordering Part  Standard Microcircuit Drawing (SMD) 

SG1548J-DESC Cross Reference 5962-8987801EA

SG1548J-DESC Cross Reference 5962-8987801EX