Mitsubishi M62021P System reset ic with switch for memory back-up Datasheet

MITSUBISHI<Dig.Ana.INTERFACE>
M62021L,P,FP
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
DESCRIPTION
PIN CONFIGURATION (TOP VIEW)
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
components.
8
CS
7
RES
6
GND
5
RES
4
Ct(DELAY CAPACITANCE)
3
VIN
2
VBAT
VOUT
1
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
Outline 8P5(L)
VOUT
VBAT
1
8
CS
2
7
RES
VIN
3
6
GND
4
5
RES
Ct(DELAY CAPACITANCE)
Outline 8P4(P)
8P2S-A(FP)
APPLICATION
Power supply control systems for memory backup of
microcomputer system and SRAM boards with built-in
backup function that require switching between external
power supply and battery.
BLOCK DIAGRAM
SW
VIN
3
VOUT
2
VBAT
8
CS
4
Ct
D1
R1
R2
1
+
Com
RESET
CIRCUIT
1.24V
RES
7
RES
5
DELAY
CIRCUIT
6
GND
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MITSUBISHI<Dig.Ana.INTERFACE>
M62021L,P,FP
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
ABSOLUTE MAXIMUM RATINGS(Ta=25°C, unless otherwise noted)
Symbol
VIN
IOUT
Pd
K
Topr
Tstg
Power dissipation
Thermal derating
Operating temperature
Storage temperature
Ratings
7
Conditions
Parameter
Input voltage
Output current
100
800(SIP)/625(DIP)/440(FP)
8(SIP)/6.25(DIP)/4.4(FP)
-20 ~ +75
(Ta≥25°C)
Unit
V
mA
mW
mW/°C
-40 ~ +125
°C
°C
ELECTRICAL CHARACTERISTICS(Ta=25°C, unless otherwise noted)
Symbol
Vs
∆Vs
Vs/∆T
ICC
VDROP
Test conditions
Parameter
Detection voltage
Hysteresis voltage
VIN(At the change from H
L)
∆Vs=VSH-VSL
Min.
4.2
50
Temperature coefficient of detection voltage
Circuit current
VIN=4V
VIN=5V
IOUT=50mA
IOUT=80mA
IOUT=0mA
Difference between input and output voltage VIN=5V
VOH(Ct) Ct output voltage (high level)
VOL(Ct) Ct output voltage (low level)
VOH(RES) RES output voltage (high level)
VIN=5V(Note1)
VIN=4V(Note1)
VIN=4V(Note1)
VOL(RES) RES output voltage (low level)
VIN=5V
VOH(RES) RES output voltage (high level)
VIN=5V(Note1)
VOL(RES) RES output voltage (low level)
4.5
3.5
4.5
VOL(CS) CS output voltage (low level)
IR
Backup Di leak current
VF
tpd
td
Backup Di forward direction voltage
Delay time
Response time
VOPL(RES) RES limit voltage of operation
VIN=0V,VBAT=3V (Note2)
(Note1)
VIN=5V
ISINK=1mA
VIN=5V
VBAT=3V
VIN=0V
IF=10µA
5V,Ct=4.7µF
VIN=0V
VIN=5V
4V
(Note 3)
Max.
4.6
200
4.0
12.0
0.25
0.4
Unit
V
mV
%/°C
mA
V
V
V
0.1
4.0
0.02
0.05
V
V
0.2
5.0
V
0.02
(Note1)
ISINK=1mA
VIN=4V (Note2)
VOH(CS) CS output voltage (high level)
100
0.005
2.0
7.5
0.125
0.2
5.0
0.02
(Note1)
ISINK=1mA
VIN=4V
Limits
Typ.
4.4
0.05
3.50
2.40
10
V
0.2
3.57
2.47
0.08
0.1
0.54
27
5.0
V
0.3
±0.5
±0.5
0.6
55
25.0
V
µA
V
ms
µs
0.65
V
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)
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MITSUBISHI<Dig.Ana.INTERFACE>
M62021L,P,FP
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
TEST CIRCUIT
V
Vm2
M62021
VIN
SW2
A
Vm1
V
1
SW1
2
3
Im1
1
R1
+
-
RES
RES
2 VBAT
Com
5
V
2
Vm4
6
CRT
6
7
instrument
ON OFF 1 OFF 1
2
3
ON OFF 1 OFF 4
5
6
1
Im1
1
(Note5)
Vm4
CRT
Vm1
A
8 CS
7
SW4
2
Im2
DELAY
CIRCUIT
SW7
1
4
SW5
1
RESET
CIRCUIT
1.24V
SW6
3
D1
R2
V1
1
2
VOUT
3
IF2 Vm3
IF1
V
V2
4 Ct
5
6
GND
SW3
4.7µ
SWITCH MATRIX
Symbol
Icc
Vs
(VSL)
VDROP
V1
Parameter
Detection voltage
IF1
VOUT
CS
Ct
RES
RES
Difference between input and output voltage
1
1
Decrease
from
5V
1
-50mA
-80mA
5V
VOH(Ct) Ct output voltage(high level)
VOL(Ct) Ct output voltage(low level)
VOH(RES) RES output voltage(high level)
5V
4V
4V
VOL(RES) RES output voltage(low level)
1mA
VOH(RES) RES output voltage(high level)
5V
5V
VOL(RES) RES output voltage(low level)
4V
1mA
VOH(CS)
CS output voltage(high level)(Note 4)
4V
0V
VOL(CS)
CS output voltage(low level)
5V
IR
Backup Di leak current
5V
0V
VF
Backup Di forward direction voltage
0V
tpd
Delay time
Response time
td
IF2
4V
5V
Circuit current
(VIN negative-going)
V2
S
3
4
W
5
Measuring
1
ON OFF 1 OFF 2
2
Vm2
1
ON OFF 1
1
Vm4
1
ON OFF 1 OFF 5
1
3V
2
OFF 4
ON OFF 1 OFF 6
2
1
2
1
Vm4
Vm4
1
ON OFF 1 OFF 3
1
ON OFF 2 OFF 1
1
Im2
1
ON OFF 3
1
1
Vm3
2
ON
2
1 OFF 3
5
6
1
CRT
Vm4
2
1mA
3V
VOUT
CS
RES
RES
1
10µA
(Note6)
ON
(Note7)
ON
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.
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MITSUBISHI<Dig.Ana.INTERFACE>
M62021L,P,FP
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
EXPLANATION OF TERMINALS
Pin No.
Symbol
1
VOUT
2
VBAT
3
VIN
4
Ct
5
RES
6
GND
7
RES
8
CS
Name
Function
VIN and VBAT are controlled by means of an internal switch and output
through VOUT
Power supply output
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
Backup power supply input
If a lithium battery is used,insert a resistor in series for safety purposes
+5V input pin.Connect to a logic power supply.
Power supply input
A delay capacitor is connected to this pin.By connecting a capacitor,it is
Delay capacitor connection pin
possible to delay each output
Connect to the positive reset input of a microcomputer.The pin is capable
Positive reset output
of flowing 1mA sink current
Ground
Reference for all signals
Connect to the negative reset input of a microcomputer.The pin is capable
Negative reset output
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
Chip select output
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
APPLICATION EXAMPLE
+5V
(MAIN POWER SUPPLY)
M62021
VIN
1
3
R1
CIN
R2
VDD
RES
RES
CPU
D1
+
1.24V
7
2
Com
VOUT
VBAT
RESET
CIRCUIT
8 CS
DELAY
CIRCUIT
5
4
VIN
VDD
CONT
BATTERY CMOS
3V
RAM
Ct
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
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MITSUBISHI<Dig.Ana.INTERFACE>
M62021L,P,FP
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
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
that the input voltage slowly drops or VR nearly equals Vref.
5
4
2
VSL
=Ct X 22kΩ X 0.2614
.
=5.75
X 10 3 X Ct
.
VSH
1
0
4.0 4.2 4.4 4.6 4.8 5.0
INPUT VOLTAGE VIN(V)
<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 is determined as follows.
Delay time(tpd)= Ct X (R3 + R4) X In
∆Vs
3
tpd
VOH(Ct)
[VOH(Ct)-VOL(Ct)]
[VOH(Ct)-INV1(VTH)]
INV1(Vth)
VOL(Ct)
*Ct is an external capacitance.
DELAYED OUTPUT WAVEFORMS OF Ct
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
supply,avoid connecting a too large capacitance.
<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
chattering.
INTERNAL CIRCUIT
Ct
VIN
RES
RES
4
3
5
7
Q4
R3
22k
R4
R1
60.94k
Com
R2
24K
Vref
1.24V
47
Q1
R7
10k
R6
R5
10k
R8
10k
Q2
VOUT
2
VBAT
8
CS
6
GND
D1
R10
800
R11
10k
INV1 INV2 INV3 INV4
Q3
INV5 INV6 INV7
R9
5k R10
INV8 INV9
22k
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M62021L,P,FP
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
TIMING CHART
tpd
tpd
5V
VIN
∆Vs
VSH
VSL
0V
V1
V2
V3
V4
V5
VOUT
V2
V4
V5
CS
VOL(CS)
5V
VIN(VSL)
RES
VOL(RES)
VOL(RES)
VIN(VSL)
RES
V1=VIN-VDROP
V2=VIN-Q4VEB(Di)
V3=VIN(VSL)-VDROP
Input
voltage
In normal operation
Input voltage:5V
Output
pin
VOUT
RES
RES
CS
With Q4 set to ON,
a voltage
(VIN-VDROP)is output
The output level is
VOL(RES)
with a logic low
Restoration from failure
(instantaneous drop)
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
VOL(RES)
V4=VIN(VSL)-Q4VEB(Di)
V5=VBAT-VF
In backup state
Input voltage:0V
Input voltage:4V 5V
Backup voltage:3V
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
VBAT-VF
A logic high is maintained,and than
shifts to a logic high
The output level is
VOH(RES)
with a logic low
As the state shifts from a logic
A logic low is held,and than shifts
high to logic low,the output level to a logic high
becomes VOL(RES)
The output level is
VOL(CS)
with a logic low
As the state shifts from a logic A logic high is maintained,and than The output is a logic high
low to logic high,the output level shifts to a logic high
and the output level is
becomes the voltage VINVBAT-VF
Q4EB(Di).
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M62021L,P,FP
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
TYPICAL CHARACTERISTICS
CIRCUIT CURRENT VS.
INPUT VOLTAGE
THERMAL DERATING
(MAXIMUM RATING)
16
1000
M62021L
14
800
12
M62021P
10
600
M62021FP
8
400
6
4
200
2
0
0
25
50
75
100
0
125
0
3
4
5
6
7
8
AMBIENT TEMPERATURE Ta(°C)
DETECTION VOLTAGE VS.
AMBIENT TEMPERATURE
INTERRUPTION OUTPUT VOLTAGE VS.
SUPPLY VOLTAGE
140
4.46
130
4.44
120
4.42
110
4.40
100
4.38
90
4.36
80
4.34
70
4.32
-40 -20 0
60
-40 -20 0
20 40 60 80 100 120
CIRCUIT CURRENT VS.
AMBIENT TEMPERATURE
4.0
VIN=5V
3.5
8
3.0
7
2.5
6
2.0
5
1.5
4
1.0
3
0.5
2
-40 -20 0
20 40 60 80 100 120
AMBIENT TEMPERATURE Ta(°C)
AMBIENT TEMPERATURE Ta(°C)
9
2
INPUT VOLTAGE Vcc(V)
4.48
10
1
CIRCUIT CURRENT VS.
AMBIENT TEMPERATURE
VIN=4V
0
-40 -20 0
20 40 60 80 100 120
20 40 60 80 100 120
AMBIENT TEMPERATURE Ta(°C)
AMBIENT TEMPERATURE Ta(°C)
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M62021L,P,FP
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
OUTPUT CURRENT VS.
DIFFERENCE BETWEEN INPUT AND OUTPUT
VOLTAGES
DIFFERENCE BETWEEN INPUT AND OUTPUT
VOLTAGES VS.
AMBIENT TEMPERATURE
100
400
VIN=5V
350
80
VIN=5V
300
60
250 IOUT=100mA
40
200 IOUT=80mA
150
IOUT=50mA
100
20
50
0
0
100
50
150
200
0
-40 -20
250
DIFFERENCE BETWEEN INPUT
AND OUTPUT VOLTAGES VDROP(mV)
20 40 60 80 100 120
AMBIENT TEMPERATURE Ta(°C)
BACKUP Di FORWARD DIRECTION
VOLTAGE VS. AMBIENT TEMPERATURE
BACKUP Di FORWARD DIRECTION
CURRENT VS. VOLTAGE
160
0.8
140
0.7
120
0.6
100
0.5
80
0.4
60
0.3
40
0.2
20
0.1
0
0
IF=100µA
IF=10µA
IF=1µA
0
-40 -20
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
0
20 40 60 80 100 120
BACKUP Di FORWARD DIRECTION VOLTAGE VF(V)
AMBIENT TEMPERATURE Ta(°C)
RES"L"OUTPUT VOLTAGE VS.
AMBIENT TEMPERATURE
RES "L"OUTPUT VOLTAGE VS.
AMBIENT TEMPERATURE
80
80
70
VIN=5V
ISINK=1mA
70
60
60
50
50
40
40
30
30
20
20
10
10
0
-40 -20
0
VIN=4V
ISINK=1mA
0
-40 -20
20 40 60 80 100 120
0
20 40 60 80 100 120
AMBIENT TEMPERATURE Ta(°C)
AMBIENT TEMPERATURE Ta(°C)
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M62021L,P,FP
SYSTEM RESET IC WITH SWITCH FOR MEMORY BACK-UP
CS"L"OUTPUT VOLTAGE VS.
AMBIENT TEMPERATURE
4.0
160
140
3.8
VIN=5V
ISINK=1mA
100
3.4
80
3.2
60
3.0
40
2.8
20
2.6
0
20 40 60 80 100 120
2.4
-40 -20
DELAY TIME VS.EXTERNAL CAPACITANCE
CONNECTED TO THE Ct PIN
1000
VIN=0V
0
20 40 60 80 100 120
AMBIENT TEMPERATURE Ta(°C)
AMBIENT TEMPERATURE Ta(°C)
7
5
VIN=4V
RCS=1MΩ
3.6
120
0
-40 -20
CS"L"OUTPUT VOLTAGE VS.
AMBIENT TEMPERATURE
5V
40
35
3
2
30
100
DELAY TIME VS.AMBIENT
TEMPERATURE
VIN=0V 5V
Ct=4.7µA
25
7
5
20
3
2
15
10
7
5
10
3
5
2
0
0.1
2 3 5 7
1
2 3
5 7
10
2 3
5 7
100
0
-40 -20
0
20 40 60 80 100 120
AMBIENT TEMPERATURE Ta(°C)
EXTERNAL CAPACITANCE CONNECTED
TO THE Ct PIN Ct(µF)
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