4
. Peripheral Schematics
Note:
To
ensure
the
power
supply
to
the
ESP32
chip
during
power-up,
it
is
advised
to
add
an
RC
delay
circuit
at
the
EN
pin.
The
recommended
setting
for
the
RC
delay
circuit
is
usually
R
=
10
k
Ω
and
C
=
0.1
µ
F.
However,
specific
parameters
should
be
adjusted
based
on
the
power-up
timing
of
the
module
and
the
power-up
and
reset
sequence
timing
of
the
chip.
For
ESP32’s
power-up
and
reset
sequence
timing
diagram,
please
refer
to
Section
Power
Scheme
in
.
VCC
GND
GND
GND
VDD33
GND
ESP Module
Discharge Circuit
CAP Added By User
Q1
R1
100K
D1
SW1
1
2
R2
1K
+
C1
Bulk CAP
Figure
2
:
Discharge
Circuit
for
VDD33
Rail
Note:
The
discharge
circuit
can
be
applied
in
scenarios
where
ESP32
is
powered
on
and
off
repeatedly
by
switching
the
power
rails,
and
there
is
a
large
capacitor
on
the
VDD33
rail.
For
details,
please
refer
to
Section
Power
Scheme
in
.
5
5
4
4
3
3
2
2
1
1
D
D
C
C
B
B
A
A
CHIP_PU
VBAT
GND
GND
Title
Size
Document Number
R e v
Date:
Sheet
o f
<Doc>
V1
<ResetCirciut>
A4
1
1
Thursday, May 31, 2018
Title
Size
Document Number
R e v
Date:
Sheet
o f
<Doc>
V1
<ResetCirciut>
A4
1
1
Thursday, May 31, 2018
Title
Size
Document Number
R e v
Date:
Sheet
o f
<Doc>
V1
<ResetCirciut>
A4
1
1
Thursday, May 31, 2018
R1
0R
R2
100K
U1
Power Supply Supervisor
GND
1
VCC
3
RESET#
2
Figure
3
:
Reset
Circuit
Note:
When battery is used as the power supply for ESP32 series of chips and modules, a supply voltage supervisor is recom-
mended to avoid boot failure due to low voltage. Users are recommended to pull CHIP_PU low if the power supply for
ESP32 is below 3.0 V.
Espressif Systems
