PIC16F62X
FIGURE 14-13: EXTERNAL POWER-ON
RESET CIRCUIT (FOR SLOW
VDD POWER-UP)
FIGURE 14-14: EXTERNAL BROWN-OUT
PROTECTION CIRCUIT 1
VDD
VDD
33k
VDD
VDD
10k
MCLR
D
R
40k
R1
PIC16F62X
MCLR
PIC16F62X
C
Note 1: External power-on reset circuit is required only
if VDD power-up slope is too slow. The diode D
helps discharge the capacitor quickly when
VDD powers down.
Note 1: This circuit will activate reset when VDD
goes below (Vz + 0.7V) where Vz = Zener
voltage.
2: Internal Brown-out Reset circuitry should be
disabled when using this circuit.
2: < 40 kΩ is recommended to make sure that
voltage drop across R does not violate the
device’s electrical specification.
3: R1 = 100Ω to 1 kΩ will limit any current flowing
into MCLR from external capacitor C in the
event of MCLR/VPP pin breakdown due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
FIGURE 14-15: EXTERNAL BROWN-OUT
PROTECTION CIRCUIT 2
VDD
VDD
R1
Q1
MCLR
R2
40k
PIC16F62X
Note 1: This brown-out circuit is less expensive,
albeit less accurate. Transistor Q1 turns off
when VDD is below a certain level such that:
R1
= 0.7 V
VDD x
R1 + R2
2: Internal brown-out reset should be disabled
when using this circuit.
3: Resistors should be adjusted for the charac-
teristics of the transistor.
DS40300B-page 106
Preliminary
1999 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
