R×5VL
OPERATION
VDD
Ra
Pch
Nch
×
××
××
+
–
OUT
×
Rb
Rc
Tr.1
GND
FIG. 1 Block Diagram
Operation Diagram
1
2
3
4
5
Step
Step 1 Step 2
Step 3
Step 4 Step 5
B
Released Volage +VDET
Detected Volage –VDET
Detector Threshold Hysteresis
A
Supply Volage
(VDD
)
Minimum Operating Volage
GND
Output Volage
(OUT)
GND
tPLH
FIG. 2 Operation Diagram
Step 1. Output Voltage is equal to Power Source Voltage (VDD).
Step 2. When Input Voltage to Comparator reaches the state of Vref ≥ VDD·(Rb+Rc)/(Ra+Rb+Rc)at Point A (Detected Voltage –VDET), the output of Com-
parator is reserved, so that Output Voltage becomes GND.
Step 3. In the case of CMOS Output, Output Voltage becomes unstable when Supply Voltage (VDD) is smaller than Minimum Operating Voltage. In the
case of Nch Open Drain Output, a pulled-up voltage is output.
Step 4. Output Voltage becomes equal to GND.
Step 5. When Input Voltage to Comparator reaches the state of Vref≤VDD·(Rb)/(Ra+Rb) at Point B (Released Voltage +VDET), the output of Comparator is reserved,
so that Output Voltage becomes equal to Supply Voltage (VDD)
14
ETC [ ETC ]
