Voltage Drop Detection Circuit; Fig. 2.8.1 Voltage Drop Detection Reset Circuit; Fig. 2.8.2 Voltage Drop Detection Circuit Operation Waveform - Renesas 4513 User Manual

APPLICATION

2.8 Voltage drop detection circuit

2.8 Voltage drop detection circuit
The built-in voltage drop detection circuit is designed to detect a drop in voltage and to reset the microcomputer
if the supply voltage drops below a set value.
Figure 2.8.1 shows the voltage drop detection reset circuit, and Figure 2.8.2 shows the operation waveform
example of the voltage drop detection circuit.
RESET pin

Fig. 2.8.1 Voltage drop detection reset circuit

V (detection voltage)
RST
Voltage drop detection
circuit output
RESET pin
Notes 1: Pull-up RESET pin externally.
2: Refer to the voltage drop detection circuit in the electrical characteristics
for the rating value of V

Fig. 2.8.2 Voltage drop detection circuit operation waveform

Note: Refer to section "3.1 Electrical characteristics" for the reset voltage of the voltage drop detection
circuit.
2-58
Note: The output structure of RESET pin is N-channel open-drain.
V
DD
RST
4513/4514 Group User's Manual
Voltage drop detection circuit
Watchdog timer output
WEF
(detection voltage).
Internal reset signal
The microcomputer starts
operation after f(X
IN
16892 to 16895 times.
) is counted