SN32F280 Series
32-Bit Cortex-M0 Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 53
Version 1.1
higher power to VDD. It is can make reset pin voltage level to synchronize with VDD voltage. The structure can improve
slight brown out reset condition.
Note: The R2 100 ohm resistor of “Simply reset circuit” and “Diode & RC reset circuit” is necessary to limit
any current flowing into reset pin from external capacitor C in the event of reset pin breakdown due
to Electrostatic Discharge (ESD) or Electrical Over-stress (EOS).
3.1.4.3
ZENER DIODE RESET CIRCUIT
MCU
VDD
VSS
VCC
GND
RST
R1
33K ohm
R3
40K ohm
R2
10K ohm
Vz
Q1
E
C
B
The Zener diode reset circuit is a simple low voltage detector and can
improve brown out reset condition completely
.
Use Zener
voltage to be the active level. When VDD voltage level is above “Vz + 0.7V”, the C terminal of the PNP
transistor outputs high voltage and
MCU operates normally. When VDD is below “Vz + 0.7V”, the C terminal of the PNP
transistor outputs low voltage and MCU is in reset mode. Decide the reset detect voltage by Zener specification. Select
the right Zener voltage to conform the application.
3.1.4.4
VOLTAGE BIAS RESET CIRCUIT
MCU
VDD
VSS
VCC
GND
RST
R1
47K ohm
R3
2K ohm
R2
10K ohm
Q1
E
C
B
The voltage bias reset circuit is a low cost voltage detector and can
improve brown out reset condition completely
.