Outline
The function of this IC is to accurately reset systems after detecting the supply voltage at the time of switching power on and instantaneous power off in various CPU and other logic systems. Further, this IC can be offered at low cost because it is designed to be simplified allowing for the replacement from reset circuit of discrete configuration.

FEATUREs
1. Voltage detect precision                                    VS±5% max.
2. Low consumption current                                   ICCH=300µA typ. ICCL=250µA typ.
3. Low operating threshold voltage                          0.65V typ.
4. Hysteresis voltage is provided as detect voltage      50mV typ.
5. Large output current at the time ON                    15mA typ.
6. Detect voltage rank PST993 C : 4.5V H: 3.1V
                                        D : 4.2V I : 2.9V
                                        E : 3.9V J : 2.7V
                                        F : 3.6V K : 2.5V
                                        G : 3.3V L : 2.3V
                                        (Same ranks for PST994 too)
7. Output form
   PST993 : Constant current load built-in
   PST994 : Open collector
  
Applications
1. Reset circuits for microcomputers, CPU and MPU.
2. Reset circuit for logic circuitry.
3. Level detecting circuit.