PIC16C620 Microchip Technology, PIC16C620 Datasheet - Page 54

• Manufacturer Part Number: PIC16C620
• Description: EPROM-Based 8-Bit CMOS Microcontroller
• Manufacturer: Microchip Technology

PIC16C62X
FIGURE 9-12: EXTERNAL POWER-ON
DS30235G-page 54
Note 1: External power-on reset circuit is required
V
DD
2: < 40 k is recommended to make sure
3: R1 = 100 to 1 k will limit any current
D
only if V
The diode D helps discharge the capaci-
tor quickly when V
that voltage drop across R does not vio-
late the device’s electrical specification.
flowing into MCLR from external capaci-
tor C in the event of MCLR/V
down due to Electrostatic Discharge
(ESD) or Electrical Overstress (EOS).
V
DD
R
RESET CIRCUIT (FOR SLOW
V
C
DD
DD
power-up slope is too slow.
POWER-UP)
R1
DD
powers down.
PIC16C62X
MCLR
PP
pin break-
Preliminary
FIGURE 9-13: EXTERNAL BROWN-OUT
FIGURE 9-14: EXTERNAL BROWN-OUT
Note 1: This brown-out circuit is less expensive,
Note 1: This circuit will activate reset when V
V
V
DD
DD
2: Internal brown-out reset should be dis-
3: Resistors should be adjusted for the
2: Internal Brown-out Reset circuitry
33k
albeit less accurate. Transistor Q1 turns
off when V
such that:
abled when using this circuit.
characteristics of the transistor.
R1
R2
goes below (Vz + 0.7V) where
Vz = Zener voltage.
should be disabled when using this cir-
cuit.
PROTECTION CIRCUIT 1
PROTECTION CIRCUIT 2
V
DD
10k
x
DD
R1 + R2
is below a certain level
1998 Microchip Technology Inc.
R1
Q1
40k
40k
= 0.7 V
PIC16C62X
PIC16C62X
MCLR
V
MCLR
V
DD
DD
DD