Datasheet

PIC16CE62X
DS40182D-page 58  1998-2013 Microchip Technology Inc.
FIGURE 10-11: EXTERNAL POWER-ON
RESET CIRCUIT (FOR SLOW
V
DD POWER-UP)
FIGURE 10-12: EXTERNAL BROWN-OUT
PROTECTION CIRCUIT 1
Note 1: External power-on reset circuit is required only
if V
DD power-up slope is too slow. The diode D
helps discharge the capacitor quickly when
V
DD powers down.
2: < 40 k is recommended to make sure that
voltage drop across R does not violate the
device’s electrical specification.
3: R1 = 100 to 1 k 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).
C
R1
R
D
V
DD
MCLR
PIC16CE62X
VDD
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.
VDD
33k
10k
40k
PIC16CE62X
VDD
MCLR
FIGURE 10-13: EXTERNAL BROWN-OUT
PROTECTION CIRCUIT 2
FIGURE 10-14: EXTERNAL BROWN-OUT
PROTECTION CIRCUIT 3
Note 1: This brown-out circuit is less expensive,
albeit less accurate. Transistor Q1 turns off
when V
DD is below a certain level such that:
2: Internal brown-out detection should be dis-
abled when using this circuit.
3: Resistors should be adjusted for the charac-
teristics of the transistor.
V
DD x
R1
R1 + R2
= 0.7 V
VDD
R2
40k
PIC16CE62X
R1
Q1
V
DD
MCLR
This brown-out protection circuit employs Microchip
Technology’s MCP809 microcontroller supervisor. The
MCP8XX and MCP1XX families of supervisors provide
push-pull and open collector outputs with both high and
low active reset pins. There are 7 different trip point
selections to accommodate 5V and 3V systems.
MCLR
PIC16CE62X
V
DD
VSS
RST
MCP809
VDD
VDD
bypass
capacitor