PIC16C662-20/TQ Microchip Technology, PIC16C662-20/TQ Datasheet - Page 65

• Manufacturer Part Number: PIC16C662-20/TQ
• Description: 8-Bit EPROM Microcontrollers with Analog Comparators
• Manufacturer: Microchip Technology

FIGURE 9-12: EXTERNAL POWER-ON
FIGURE 9-13: EXTERNAL BROWN-OUT
1996 Microchip Technology Inc.
Note 1: External power-on reset circuit is required
Note 1: This circuit will activate reset when V
V
DD
V
2: R < 40 k is recommended to make sure
3: R1 = 100 to 1 k will limit any current
DD
D
2: Internal Brown-out Reset circuitry
3: Resistors should be adjusted for the
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
breakdown due to Electrostatic Dis-
charge (ESD) or Electrical Overstress
(EOS).
33k
goes below (Vz + 0.7V) where
Vz = Zener voltage.
should be disabled when using this cir-
cuit.
characteristics of the transistor.
V
DD
R
RESET CIRCUIT (FOR SLOW
V
PROTECTION CIRCUIT 1
C
DD
DD
10k
power-up slope is too slow.
POWER-UP)
R1
DD
40k
powers down.
MCLR
MCLR
V
PIC16CXXX
PIC16CXXX
DD
PP
pin
DD
Preliminary
PIC16C64X & PIC16C66X
FIGURE 9-14: EXTERNAL BROWN-OUT
Note 1: This brown-out circuit is less expensive,
V
DD
2: Internal Brown-out Reset circuitry
3: Resistors should be adjusted for the
albeit less accurate. Transistor Q1 turns
off when V
such that:
should be disabled when using this cir-
cuit.
characteristics of the transistor.
R1
R2
PROTECTION CIRCUIT 2
V
DD
•
DD
R1 + R2
is below a certain level
R1
Q1
40k
= 0.7 V
MCLR
DS30559A-page 65
V
PIC16CXXX
DD