Datasheet M62021P, M62021L, M62021FP Datasheet (Mitsubishi)

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components.

power supply and battery.

1

M62021L,P,FP

SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP

DESCRIPTION

The M62021 is a system IC that controls the memory backup
function of SRAM and microcomputer (internal RAM).
The IC outputs reset signals(RES/RES) to a microcomputer
at power-down and power failure.It also shifts the power
supply to RAM from main to backup,outputs a signal (CS) that
invokes standby mode,and alters RAM to backup circuit mode.
The M62021 contains,in a single chip,power supply monitor
and RAM backup functions needed for a microcomputer
system,so that the IC makes it possible to construct a system
easily and with fewer components compared with a
conventional case that uses individual ICs and discrete

FEATURES

•Built-in switch for selection between main power supply and
backup power supply to RAM.

•Small difference between input and output voltage
(IOUT=80mA,VIN=5V)0.2V typ

•Detection voltage (power supply monitor voltage)4.40V±0.2V

•Chip select signal output(CS)
Two channels of reset outputs(RES/RES)

•Power on reset circuit built-in

•Delay time variable by an external capacitance connected to
Ct pin

•Facilitates to form backup function with a few number of
components

APPLICATION

Power supply control systems for memory backup of

microcomputer system and SRAM boards with built-in
backup function that require switching between external

PIN CONFIGURATION (TOP VIEW)

8

CS

7

RES

6

GND

5

RES

4

Ct(DELAY CAPACITANCE)

3

VIN

2

VBAT

1

VOUT

Outline 8P5(L)

VBAT

VIN

1
2
3
4

Outline 8P4(P)
8P2S-A(FP)

VOUT

Ct(DELAY CAPACITANCE)

8

CS

7

RES

6

GND

5

RES

BLOCK DIAGRAM

VIN

3

RES

7

RES

5

R1

R2

­+

1.24V

Com

RESET
CIRCUIT

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SW

DELAY
CIRCUIT

6

GND

D1

2
8

4

VOUT

VBAT

CS

Ct

1

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M62021L,P,FP

SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP

ABSOLUTE MAXIMUM RATINGS(Ta=25°C, unless otherwise noted)

Symbol Ratings

VIN

IOUT

Pd
K
Topr
Tstg Storage temperature

Input voltage

Output current

Power dissipation

Thermal derating
Operating temperature

Parameter

(Ta≥25°C)

ELECTRICAL CHARACTERISTICS(Ta=25°C, unless otherwise noted)

Symbol

Vs

Detection voltage

∆Vs

Hysteresis voltage

Vs/∆T

VDROP

VOH(Ct)

VOL(Ct)

VOH(RES)

VOH(RES)

VOL(RES)

VOH(CS)

VOL(CS)

VOPL(RES)

Note 1.Regarding conditions to measure VOH and VOL,voltage values are to be generated by internal resistance only and no external resistor is used.

2.These values are produced inserting an external resistor,RCS=1MΩ,between the CS pin and GND.

3.With no external resistor (10kΩ internal resistance only)

Temperature coefficient of detection voltage

Circuit current

ICC

Difference between input and output voltage

Ct output voltage (high level)
Ct output voltage (low level)

RES output voltage (high level)

RES output voltage (low level)VOL(RES)

RES output voltage (high level)

RES output voltage (low level)

CS output voltage (high level)

CS output voltage (low level) VIN=5V

Backup Di leak current

IR

VF

Backup Di forward direction voltage

tpd

Delay time

Response time

td

RES limit voltage of operation

Parameter

VIN(At the change from H L)

∆Vs=VSH-VSL

IOUT=0mA

VIN=5V

VIN=5V(Note1)
VIN=4V(Note1)
VIN=4V(Note1)

VIN=5V

VIN=5V(Note1)

VIN=4V

(Note2)

VIN=4V
VIN=0V,VBAT=3V

VBAT=3V

IF=10µA
VIN=0V

VIN=5V
(Note 3)

Conditions

Test conditions

(Note2)

5V,Ct=4.7µF
4V

VIN=4V

VIN=5V

IOUT=50mA
IOUT=80mA

(Note1)

ISINK=1mA

(Note1)
ISINK=1mA

(Note1)
ISINK=1mA

VIN=5V

VIN=0V

7

100

800(SIP)/625(DIP)/440(FP)

8(SIP)/6.25(DIP)/4.4(FP)

-20 ~ +75

-40 ~ +125

Limits

Min.

4.2
50 200

4.5

3.5

4.5

3.50

2.40

10

Typ.

4.4

2.0

7.5

0.125

0.2

5.0

0.02

4.0

0.02

0.05

5.0

0.02

0.05

3.57

2.47

0.08

0.1

0.54
27

5.0

0.65

Max.

4.6

4.0

12.0

0.25

0.4

0.1

0.2

0.2

0.3

±0.5
±0.5

0.6
55

25.0

Unit

V

mA

mW

mW/°C

°C
°C

Unit

V

mV100

%/°C0.005

mA

V
V

V
V

V
V

V

V

V

µA

V

ms

µs

V

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1.24VR1R2

D1

TEST CIRCUIT

CRT1234

56SW5

SW6

SW712

IF1

Vm4

SW4

SW3

4.7µ

Vm3

IF2

V2

Im2123Vm2

VIN

SW2

Im1

Measuring

instrument

(Note6)

(Note7)

SW112

V1

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M62021L,P,FP

SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP

V

M62021

1

2

8
4

VOUT

VBAT

CS

Ct

V

A

V

Vm1

A

V

RES
RES

3

Com

+

-

7

RESET
CIRCUIT

DELAY
CIRCUIT

5

6

GND

SWITCH MATRIX

ON

ON

ON
ON

ON

ON

ON

ON
ON

ON

S W

OFF

OFF

OFF
OFF

OFF

OFF

OFF

OFF
OFF

ON

7

1

OFF

1

1

OFF

1

OFF

OFF

1

1

OFF

1

2

3
4

5
6

2
4

5

1

2
1

1

(Note5)
Vm4
CRT
Vm1

2

1

OFF

1

6

2

OFF

1

1

3

2

2
3

OFF

ON

1

1

1

1

2

OFF

3

1

5

1

6

Symbol

Icc

Parameter

Circuit current

V1 V2 IF1
4V

5V

IF2

1 2 3 4 5 6
1

VOUT

Decrease

Vs
(VSL)

Detection voltage

(VIN negative-going)

CS

Ct

RES

from
5V

1

RES

3V

3V

-50mA

-80mA

1mA

1mA

1mA

10µA

1
1

1

1

1

1
1

2

VDROP

VOH(Ct)
VOL(Ct)

VOH(RES)

VOL(RES)

VOH(RES)

VOL(RES)

VOH(CS)
VOL(CS)

IR

VF

tpd

td

Difference between input and output voltage

Ct output voltage(high level)
Ct output voltage(low level)

RES output voltage(high level)

RES output voltage(low level)
RES output voltage(high level)
RES output voltage(low level)

CS output voltage(high level)(Note 4)
CS output voltage(low level)
Backup Di leak current
Backup Di forward direction voltage

Delay time
Response time

VOUT

CS

RES

5V

5V
4V

4V
5V

5V
4V

4V
0V

5V
5V

0V

0V

RES

Notes 4.To measure VOH(CS),insert a 1MΩ resistor between the CS pin and GND.

5. While monitoring each output by Vm4 or CRT,measure the input voltage Vm1 when the output goes from H to L and L to H.Regarding VSH,raise VIN
from 4V and measure the input voltage Vm1 when the output goes from H to L and L to H.∆Vs is VSH-VSL.

6. To measure delay time, change VIN from 0V to 5V and compare,with respect to each pin,the positive-going edge observed on a monitor with that
of VIN.To measure response time,change VIN from 5V to 4V and compare,with respect to each pin,the negative-going edge observed on a monitor
with that of VIN.

7.Set the switch to OFF when measuring response time.

Im1

Vm2
Vm4

Vm4

Vm4

Vm4

Im2

Vm3

CRT

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4

EXPLANATION OF TERMINALS

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M62021L,P,FP

SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP

Pin No.

1

2 VBAT
3
4

5
6

7

8

Symbol Name

VOUT

VIN

Ct Delay capacitor connection pin

RES
GND
RES

CS

Power supply output

Backup power supply input

Power supply input

Positive reset output
Ground

Negative reset output

Chip select output

APPLICATION EXAMPLE

Function

VIN and VBAT are controlled by means of an internal switch and output
through VOUT
The pin is capable of outputting up to 100mA.Use it as VDD of CMOS RAM
and the like
Backup power supply is connected to this pin
If a lithium battery is used,insert a resistor in series for safety purposes
+5V input pin.Connect to a logic power supply.

A delay capacitor is connected to this pin.By connecting a capacitor,it is
possible to delay each output

Connect to the positive reset input of a microcomputer.The pin is capable
of flowing 1mA sink current

Reference for all signals
Connect to the negative reset input of a microcomputer.The pin is capable

of flowing 1mA sink current

Connect to the chip select of RAM.The CS output is at low level in normal
state thereby letting RAM be active.Under failure or backup condition,the CS
output is set to high level,then RAM enters standby state disabling read/write
function.The pin is capable of flowing a 1mA sink current

+5V
(MAIN POWER SUPPLY)

CIN

VDD

CPU

VIN

RES
RES

M62021

VOUT

D1

1

2

8
4

VBAT

CS

Ct

3

R1

Com

+

R2

-

1.24V

7

5

RESET
CIRCUIT

DELAY
CIRCUIT

6

GND

*Capacitance to be connected:CIN:10µF;COUT:4.7µF;Ct:4.7µF
*If connecting a zener diode,select one of VZ=2~3V

VIN

BATTERY
3V

VDD

CONT

CMOS
RAM

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SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP

that the input voltage slowly drops or VR nearly equals Vref.

Delay time is determined as follows.

3

supply,avoid connecting a too large capacitance.

chattering.

CONFIGURATION

<Power supply detector>

The internal reference voltage Vref is compared by means of
a comparator with resistor-divided voltage VR(resistor-divided
voltage produced by R1 and R2 from VIN).
If the input voltage is 5V,VR is set to 1.24V or higher,so the
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.
The comparator used for detection has 100mV
hysteresis(∆Vs),so that malfunctioning is prevented in case

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M62021L,P,FP

5
4

3
2
1

0

4.0

VSL VSH

4.2

∆Vs

4.4 4.6 4.8

5.0

<Delay Circuit>

Connecting an external capacitor to the Ct pin lets
RES,RES,CS,and VOUT be delayed due to RC transient
phenomenon(electric charge).

Delay time(tpd)= Ct X (R3 + R4) X In

=Ct X 22kΩ X 0.2614
.

=5.75 X 10 X Ct *Ct is an external capacitance.

.

Taking into consideration the time taken by the oscillator of
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

<Schmitt trigger circuit>

Since waveforms show a gentle rise due to the RC delay
circuit,INV1,INV2,R5,and R6 constitute a schmitt trigger circuit
to produce hysteresis so as to prevent each output from

[VOH(Ct)-VOL(Ct)]

[VOH(Ct)-INV1(VTH)]

INTERNAL CIRCUIT

Ct

4

R2
24K

R1

60.94k

1.24V

Vref

Com

R3
22k

R4 R5
47

Q1

10k

R6

INV1

INV2

VIN

3

INV3 INV4

INV5

INV8

INPUT VOLTAGE VIN(V)

tpd

DELAYED OUTPUT WAVEFORMS OF Ct

RES RES

R8

R7

10k 10k

Q2

Q3

INV7

INV6

R9

5k

INV9

R10

22k

75

R10

800

Q4

Q5

VOH(Ct)

INV1(Vth)

VOL(Ct)

R11
10k

D1

1

2

8

6

VOUT

VBAT

CS

GND

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5

The output is a logic high
and the output level is
VBAT-VF

TIMING CHART

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M62021L,P,FP

SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP

VIN

0V

VOUT

CS

RES

5V

tpd

tpd

∆Vs

VSH
VSL

V1
V2

V3
V4

V5

V2
V4
V5

VOL(CS)
5V

VIN(VSL)

VOL(RES)
VOL(RES)

VIN(VSL)

Input
voltage

Output
pin

VOUT

RES

RES

CS

RES

In normal operation

Input voltage:5V

With Q4 set to ON,

a voltage

(VIN-VDROP)is output

The output level is

VOL(RES)

with a logic low

The output level is

VOH(RES)

with a logic low

The output level is

VOL(CS)

with a logic low

In failure(instantaneous drop)

Input voltage:5V 4V
Each output varies if the input
voltage drops to VSL or under

Q4 is turned OFF.A voltage
(VIN-Q4 VEB(Di) is output by
the diode between E and B of
Q4

As the state shifts from a logic
low to logic high,the output level
becomes approximately equal to
the input voltage

As the state shifts from a logic
high to logic low,the output level
becomes VOL(RES)

As the state shifts from a logic
low to logic high,the output level
becomes the voltage VIN­Q4EB(Di).

V1=VIN-VDROP
V2=VIN-Q4VEB(Di)
V3=VIN(VSL)-VDROP

V4=VIN(VSL)-Q4VEB(Di)
V5=VBAT-VF

Restoration from failure

(instantaneous drop)

Input voltage:4V 5V
If the input voltage goes higher
than VSL by 100mV,each out-put
varies after delay produced by the
delay circuit

Q4 is turned ON after delay and
a voltage(VIN-VDROP) is output

A logic high is maintained,and than
shifts to a logic high

A logic low is held,and than shifts
to a logic high

A logic high is maintained,and than
shifts to a logic high

VOL(RES)

In backup state

Input voltage:0V
Backup voltage:3V

VBAT-VF

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SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP

TYPICAL CHARACTERISTICS

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M62021L,P,FP

1000

800

600

400

200

4.48

4.46

4.44

4.42

4.40

4.38

4.36

4.34

4.32

THERMAL DERATING

(MAXIMUM RATING)

M62021L

M62021P

M62021FP

0

0

25

50

75

AMBIENT TEMPERATURE Ta(°C)

DETECTION VOLTAGE VS.

AMBIENT TEMPERATURE

-20

-40

0 20 40 80

AMBIENT TEMPERATURE Ta(°C)

60

100

100

125

120

CIRCUIT CURRENT VS.

INPUT VOLTAGE

16
14
12

10

8
6

4
2

0

0 1 2 3

INPUT VOLTAGE Vcc(V)

INTERRUPTION OUTPUT VOLTAGE VS.

140
130
120
110

100

90
80

70
60

-40

SUPPLY VOLTAGE

-20

0 20 40 80

AMBIENT TEMPERATURE Ta(°C)

4

5 6 7 8

60

100

120

CIRCUIT CURRENT VS.

10

9

8

7

6

5

4

3

2

-40

AMBIENT TEMPERATURE

VIN=5V

-20

0 20 40 80

AMBIENT TEMPERATURE Ta(°C)

60

100

120

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CIRCUIT CURRENT VS.

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

AMBIENT TEMPERATURE

VIN=4V

0

-20

-40

0 20 40 80

AMBIENT TEMPERATURE Ta(°C)

60

100

120

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M62021L,P,FP

SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP

DIFFERENCE BETWEEN INPUT AND OUTPUT

100

80

60

40

20

0

160

140

120

100

80

60

40

OUTPUT CURRENT VS.

VOLTAGES

VIN=5V

0

DIFFERENCE BETWEEN INPUT
AND OUTPUT VOLTAGES VDROP(mV)

BACKUP Di FORWARD DIRECTION

CURRENT VS. VOLTAGE

50

100

150 200

250

DIFFERENCE BETWEEN INPUT AND OUTPUT

400
350

300
250

IOUT=100mA

200

IOUT=80mA

150

IOUT=50mA

100

50

0

-40

AMBIENT TEMPERATURE Ta(°C)

BACKUP Di FORWARD DIRECTION

VOLTAGE VS. AMBIENT TEMPERATURE

0.8

0.7

0.6

0.5

0.4

0.3

0.2

VOLTAGES VS.

AMBIENT TEMPERATURE

VIN=5V

-20

20

0

40

60 80

100

IF=100µA

IF=10µA

IF=1µA

120

20

0

0

0.2 0.3 0.4 0.5 0.6 0.7

0.1

BACKUP Di FORWARD DIRECTION VOLTAGE VF(V)

RES"L"OUTPUT VOLTAGE VS.

80
70
60

50
40
30
20
10

0

AMBIENT TEMPERATURE

VIN=5V
ISINK=1mA

-40

-20

AMBIENT TEMPERATURE Ta(°C)

20

0

40

60 80

100

0.8

120

0.1
0

-40

-20

AMBIENT TEMPERATURE Ta(°C)

RES "L"OUTPUT VOLTAGE VS.

80

VIN=4V

70

ISINK=1mA

60
50

40
30
20
10

0

-40

-20

AMBIENT TEMPERATURE Ta(°C)

20

20

40

40

0

AMBIENT TEMPERATURE

0

60 80

60 80

100 120

100 120

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5

M62021L,P,FP

SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP

CS"L"OUTPUT VOLTAGE VS.

160

140

120

100

80

60
40
20

1000

100

AMBIENT TEMPERATURE

VIN=5V
ISINK=1mA

0

-40

-20

AMBIENT TEMPERATURE Ta(°C)

DELAY TIME VS.EXTERNAL CAPACITANCE

VIN=0V 5V

20

0

CONNECTED TO THE Ct PIN

40

60 80

100 120

CS"L"OUTPUT VOLTAGE VS.

4.0

3.8

3.6

3.4

3.2

3.0

2.8

2.6

2.4

40
35
30
25

AMBIENT TEMPERATURE

VIN=4V
RCS=1MΩ

-40

-20

AMBIENT TEMPERATURE Ta(°C)

DELAY TIME VS.AMBIENT

VIN=0V 5V
Ct=4.7µA

20

0

40

TEMPERATURE

60 80

100

120

10

0

0.1

EXTERNAL CAPACITANCE CONNECTED

1 10 100

TO THE Ct PIN Ct(µF)

20
15
10

5
0

-40

-20

AMBIENT TEMPERATURE Ta(°C)

20

0

40

60 80

100 120

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