M62021 Mitsubishi, M62021 Datasheet - Page 5

• Manufacturer Part Number: M62021
• Description: SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
• Manufacturer: Mitsubishi

CONFIGURATION
<Power supply detector>
a comparator with resistor-divided voltage VR(resistor-divided
voltage produced by R1 and R2 from VIN).
comparator output is at low level and the Ct output(Q1
collector output)is set to high level.If the input voltage drops to
below 4.4V in an abnormal condition,VR becomes below
1.24V,so the comparator output goes from low to high level
and the Ct output,from high to low.The input voltage at this
point is called VSL.Next,when the input voltage,restored from
abnormal state,has a rise,the comparator output goes from
high to low level and the Ct output,from low to high.
hysteresis( Vs),so that malfunctioning is prevented in case
that the input voltage slowly drops or VR nearly equals Vref.
<Delay Circuit>
RES,RES,CS,and VOUT be delayed due to RC transient
phenomenon(electric charge).
<Schmitt trigger circuit>
circuit,INV1,INV2,R5,and R6 constitute a schmitt trigger circuit
to produce hysteresis so as to prevent each output from
chattering.
Delay time(tpd)= Ct X (R3 + R4) X In
microcomputer to be stable,connect a 4.7µF capacitor to the
Ct pin.
(As the response time of detection can be slowed due to
internal structure depending on the rising rate of power
supply,avoid connecting a too large capacitance.
The internal reference voltage Vref is compared by means of
If the input voltage is 5V,VR is set to 1.24V or higher,so the
The comparator used for detection has 100mV
Connecting an external capacitor to the Ct pin lets
Delay time is determined as follows.
INTERNAL CIRCUIT
Since waveforms show a gentle rise due to the RC delay
Taking into consideration the time taken by the oscillator of
R2
24K
=Ct X 22k X 0.2614
.
=5.75 X 10 X Ct
.
R1
60.94k
1.24V
Vref
3
Com
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
[VOH(Ct)-INV1(VTH)]
*Ct is an external capacitance.
[VOH(Ct)-VOL(Ct)]
Q1
R3
22k
R4
47
Ct
4
10k
R5
INV1 INV2
MITSUBISHI
ELECTRIC
R6
V
3
IN
INV3 INV4
INV5 INV6 INV7
INV8 INV9
DELAYED OUTPUT WAVEFORMS OF Ct
MITSUBISHI<Dig.Ana.INTERFACE>
M62021L,P,FP
5
4
0
3
2
1
4.0 4.2 4.4 4.6 4.8 5.0
10k
R7
R9
INPUT VOLTAGE V
5k
RES
Q2
5
tpd
R8
10k
V
R10
22k
SL
Q3
RES
R10
800
7
V
SH
Q4
Q5
Vs
V
OH
INV1(Vth)
V
R11
10k
IN
OL
(Ct)
(V)
(
(Ct)
D1
5
1
2
8
6
/ 9 )
V
GND
V
CS
OUT
BAT