Part Number : PST593DM
Function : System reset / Monolithic IC, PST591~595 Series
Package : TO-92A, MMP-4A Type
Maker : Mitsumi
Pinouts : 
Description :
These ICs function in a variety of CPU systems and other logic systems, to detect power supply voltage and reset the system accurately when power is turned on or interrupted, and has a built-in fixed delay time generating circuit. This series has been represented in the past by PST574 / PST575, but these new low reset type system reset ICs expand the delay time series with a counter timer using an analog/digital hybrid circuit.
Circuit Diagram
Features :
1. Low operating limit voltage
2. Hysteresis voltage provided in detection voltage
3. Current consumption for no-load
4. 5 delay time products available
Datasheet PDF Download : 
Others datasheet of same file :
PST573C, PST573CM, PST573D, PST573-DM, PST573E