The ADM1085/ADM1086/ADM1087/ADM1088 are simple sequencing circuits that provide a time delay between the enabling of voltage regulators and/or dc-dc converters at powerup in multiple supply systems. When the output voltage of the first power module reaches a preset threshold, a time delay is initiated before an enable signal allows subsequent regulators to power up. Any number of these devices can be cascaded with regulators to allow sequencing of multiple power supplies. Threshold levels can be set with a pair of external resistors in a voltage divider configuration. With appropriate resistor values, the threshold can be adjusted to monitor voltages as low as 0.6 V. The ADM1086 and ADM1088 have push-pull output stages, with active high (ENOUT) and active low (ENOUT) logic outputs, respectively. The ADM1085 has an active-high (ENOUT) logic output; the ADM1087 has an active-low (ENOUT) output. Both the ADM1085 and ADM1087 have open-drain output stages that can be pulled up to voltage levels as high as 22 V through an external resistor. This level-shifting property ensures compatibility with enable input logic levels of different regulators and converters.