MITSUMI
System Reset (Built-in Watch Dog Timer) MM1099
System Reset (Built-in Watch Dog Timer)
Monolithic IC MM1099
Outline
The function of this IC series MM1099 is to accurately reset systems, a generating reset signal at the time of
instantaneous supply voltage off or lowering in varied CPU and other logic system.
Further, with the watch dog timer built-in it can diagnose the operation of the system, intermittently
generating reset pulses when they operate erroneously to prevent runaway.
Features
1.
2.
3.
4.
5.
Built-in watch dog timer
Low current consumption
130µA TYP.
Low operating threshold voltage
V
CC
=0.8V
Watch dog stop function (RCT terminal)
Long clock monitoring time
T
PR
(POWER ON) : T
WD
(clock monitoring)=1 : 1
6. Fewer outer components
Package
DIP-8B (MM1099AD, MM1099BD)
SOP-8C (MM1099AF, MM1099BF)
SIP-8A (MM1099AS, MM1099BS)
Applications
1. Reset circuit for microcomputers, CPU and MPU.
2. Reset circuit for logic circuitry.
3. Monitoring of microcomputer system, etc.
Pin Assignmemt
1
2
3
8
7
6
5
4
5
1
2
3
4
6
7
SOP-8C/DIP-8B
(TOP VIEW)
8
TC
N.C
CK
GND
V
CC
RCT
V
S
------------------------------
-----------------------------
1
2
3
4
1 2 3 4 5 6 7 8
SIP-8A
5
6
7
8
TC
N.C
CK
GND
V
CC
RCT
V
S
------------------------------
-----------------------------
RESET
RESET
MITSUMI
System Reset (Built-in Watch Dog Timer) MM1099
Pin Description
Pin No. Pin name
TC
N.C
CK
GND
V
CC
RCT
V
S
RESET
Clock input terminal Inputs the clock from the logic system.
Ground terminal
Voltage detection
MM1099A
3.2V MM1099B
4.2V
OPEN, Stop
connect to GND
Watchdog timer stop pin Operation modes: Operation
Detect voltage variable terminal
Reset output pin (low output)
Variable terminals T
WD
, T
WR
and T
PR
The time for T
WD
, T
WR
and T
PR
to be
determined by the external capacitor.
2
3
4
5
6
7
8
Function
T
PR
(ms) = 5000 C
T
(µF)
T
WD
(ms) = 500 C
T
(µF)
T
WR
(ms) = 100
C
T
(µF)
1
Absolute Maximum Ratings
Item
Power supply voltage
CK pin input voltage
V
S
pin input voltage
Voltage applied to RCT pin
----------------------------------------------------
Symbol
V
CC
max.
V
CK
V
VS
V
RCT
V
OH
Pd
T
STG
Rating
-0.3~+10
-0.3~V
CC
+0.3 ( < +10)
=
-0.3~V
CC
+0.3 ( < +10)
=
-0.3~V
CC
+0.3 ( < +10)
=
-0.3~V
CC
+0.3 ( < +10)
=
300
-40~+125
Units
V
V
V
V
V
mW
°
C
Voltage applied to RESET pin
Allowable loss
Storage temperature
Recommended Operating Conditions
Item
Power supply voltage
----------------------------------------------------
Symbol
V
CC
I
OL
T
WD
t
FC
, t
RC
C
T
T
OP
Rating
+2.2~+7.0
0~1.0
0.1~1000
<100
0.0002~2
-25~+75
Units
V
mA
ms
µs
µF
°
C
RESET sync current
Clock monitoring time setting
Clock rise and fall times
TC pin capacitance
Operating temperature
MITSUMI
System Reset (Built-in Watch Dog Timer) MM1099
Electrical Characteristics (DC)
Item
Consumption current
MM1099A
MM1099B
MM1099A
Detection voltage
MM1099B
MM1099A
MM1099B
Detection voltage temperature coefficient
Hysteresis voltage
MM1099A
MM1099B
V
SH
(Except where noted otherwise, MM1099A : V
CC
=3.6V, Ta=25
°
C, MM1099B : V
CC
=5.0V)
Measurement conditions
During watchdog timer operation
V
S
=OPEN, V
CC
V
S
=OPEN, V
CC
Min. Typ. Max. Units
(100) (150)
130
195
3.10 3.20 3.30
4.05 4.20 4.35
3.15 3.25 3.35
4.15 4.30 4.45
±0.01
V
SH
-V
SL
, V
CC
25
50
0.8
A : V
CK
=3.6V, B : V
CK
=5.0V
V
CK
=0V
I
RESET
=-1µA, V
S
=OPEN
I
RESET
=0.5mA, V
S
=0V
I
RESET
=1.0mA, V
S
=0V
V
RESET
=1.0V, V
S
=0V
----------------------------------------------------
----------------------------------------------------
----------------------------------------------------
----------------------------------------------------
Symbol
I
CC
V
SL
µA
V
V
S
/ T
V
HYS
V
TH
I
IH
I
IL
V
OH
V
OL
1
V
OL
2
I
OL
I
CT
1
I
CT
2
%/
°
C
100
150
2
1
-2
mV
V
µA
V
0.4
0.5
V
mA
µA
µA
V
50
100
1.2
0
-6
3.4
4.5
0.2
0.3
CK input threshold
CK input current
Output voltage
(High)
MM1099A
MM1099B
-12
3.0
4.0
Output voltage (Low)
R output sync current
C
T
charge current
Minimum operating power
supply voltage to ensure RESET
---------------------------------------------------
1
2
V
TC
=1.0V during watchdog timer operation -0.16 -0.24 -0.48
V
TC
=1.0V during power ON reset operation -0.16 -0.24 -0.48
V
RESET
=0.4V
I
RESET
=0.1mA
----------------------------------------------------
----------------------------------------------------
V
CCL
0.8
1.0
MITSUMI
System Reset (Built-in Watch Dog Timer) MM1099
Electrical Characteristics (AC)
Item
MM1099A
T
PI
MM1099B
T
CKW
T
CK
T
WD
T
WR
T
PR
V
CC
CK
Symbol
V
CC
(Except where noted otherwise, MM1096A : V
CC
=3.6V, Ta=25°C MM1096B : V
CC
=5.0V)
(Except where noted otherwise, resistance unit is
Ω)
Measurement conditions
3.6V
2.8V
5.0V
4.0V
or
Min.
8
Typ.
Max.
Units
V
CC
input
pulse width
µs
8
3
20
C
T
=0.02µF
C
T
=0.02µF
50
1
50
100
2
100
2
2.0
0.2
150
3
150
10
4.0
1.0
µs
µs
ms
ms
ms
µs
µs
µs
CK input pulse width
CK input cycle
Watchdog timer
monitoring time 1
*
Reset time for
watchdog timer 2
*
Reset hold time for
power supply rise 3
*
C
T
=0.02µF, V
CC
----------------------------------------------------------------------
Output delay time from V
CC
4
*
T
PD
t
R
t
F
RESET pin, R
L
=10k, C
L
=20pF
----------------------------------------------------------------------
Output rise time 5
*
Output fall time 5
*
RESET pin, R
L
=10k, C
L
=20pF
----------------------------------------------------------------------
RESET pin, R
L
=10k, C
L
=20pF
Notes :
1 The "monitoring time" means the time interval from the last pulse of the clock pulses for timer clear
(negative edge) to the output of the reset pulse. If the clock pulse is not input during this time interval, the
reset output will be given.
2 The "reset time" is no other than the reset pulse width, except when resetting the POWER ON.
3 The "reset hold time" is the time interval from the time point when V
CC
exceeds the detect (V
SH
) at the time
of Power On Reset (Power variation reset) to the reset release (RESET output "HIGH").
4 The "output delay time" means the time interval from when the supply voltage comes lower than the
detect voltage (V
SL
) to when comes the reset state (RESET output "Low").
5 The voltage range is 10 to 90% when measuring the output rise and fall times.
6 By varying the capacitance of C
T
, we can vary the watch dog timer monitoring time (T
WD
), the reset time at
the time of the watch dog timer (T
WR
), and the reset hold time at the time of power source rise (T
PR
). The
variable time can be expressed by the following formulas:
T
PR
(ms) . . 5000 C
T
(µF)
=
T
WD
(ms) . . 5000 C
T
(µF)
=
. 100 C
T
(µF)
T
WR
(ms) =
.
Example : When CT=0.02µF
T
PR
. . 100ms
=
T
WD
. . 100ms
=
T
WR
. . 2ms
=
*
*
*
*
*
*
-------------------------------------------------
-------------------------------------------------
MITSUMI
System Reset (Built-in Watch Dog Timer) MM1099
Measuring Circuits
Measuring Circuit 1 (DC)
Measuring Circuit 2 (AC)
Measuring Circuit 1
Item
Consumption current
Detection voltage
CK input threshold
CK input current
Output voltage (High)
Output voltage (Low)
Output sink current
C
T
charge current 1
C
T
charge current 2
Minimum operating power
---------------------------
---------------------------
SW & Power Supply Table
V
CC
3.6V
3.6V 3V
3V 3.6V
3.6V
3.6V
3.6V
3.6V
3.6V
3.6V
3.6V
3.6V
0V 2V
V
CK
3.6V
0V
0V
3.6V
0V
3.6V
3.6V
3.6V
3.6V
-
-
0V
V
CT
0V
2V
2V
1V
0V
0V
2V
2V
2V
2V
1V
IV
0V
I
RESET
-
-
-
-
-
-
-1µA
0.5mA
1.0mA
-
-
-
-
-----------------------------------------------
Symbol SW1 SW2 SW3 SW4 SW5 SW6 SW7
I
CC
V
SL
V
SH
V
TH
I
IH
I
IL
V
OH
V
OL
1
V
OL
2
I
OL
1
I
TC
1
I
TC
2
V
CCL
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
OFF
OFF
OFF
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
OFF
OFF
OFF
OFF
ON
ON
OFF
OFF
OFF
ON
ON
ON
ON
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
ON
A
A
A
A
A
A
A
A
A
B
A
A
A
VM, IM
I
CC
V
O
1, CRT1
V
O
1, CRT1
I
CK
, V
CK
I
CK
I
CK
V
O
1
V
O
1
V
O
1
I
O
1
I
TC
I
TC
V
O1
, V
CC
Notes
3.6V 0V 3V
V
O
=1V
supply voltage to ensure RESET
Measuring Circuit 2
Item
V
CC
input pulse width
T
P
1
CK input pulse width
T
CKW
CK input cycle
Watchdog timer
monitoring time
Reset time
for watchdog timer
Reset hold time for
power supply rise
Output delay time
from V
CC
Output rise time
Output fall time
T
CK
T
WD
T
WR
T
PR
T
PD
T
R
T
F
SW & Power Supply Table
V
CCA
3.6V
2.8V
-
-
-
-
-
3.6V
0V
-
-
T1
V
CC
-
3.6V
3.6V
3.6V
3.6V
3.6V
-
3.6V
3.6V
1.4V
0V
1.4V
0V
1.4V
0V
-
-
-
-
-
-
T2
or
T2
T2
T3
-
-
3.6V
3.6V
3.6V
0V
3.6V
3.6V
V
CKA
T2
T3
V
CK
-
CRT
CRT1
CRT2
CRT1
CRT2
CRT1
CRT2
CRT1
CRT2
CRT1
CRT2
CRT1
CRT2
CRT1
CRT1
CRT1
Notes
T1=8µs
T2=3µs
T3=20µs
Symbol SW1 SW2
C
A
A
A
A
B A
C
A
A
B
B
B
A
A
A
A
A
A