Model
V
SLB
V
SLR
T
PR
T
WD
T
WR
MM1135
100mS
10mS
2mS
MM1136
3.4V
3.2V
100mS
100mS
2mS
MITSUMI
System Reset (with built-in watchdog timer) MM1135, MM1136
System Reset (with built-in watchdog timer)
Monolithic IC MM1135, MM1136
Outline
These ICs were developed to drive low voltage batteries, and have a watchdog timer with built-in
microcomputer reset voltage detection circuit and low battery detection circuit.
A single reference voltage is used for low battery voltage detection and microcomputer reset voltage
detection, so detection voltage difference is uniform (
.
=. 0.2V). Further, there is a built-in watchdog timer for
operation diagnosis, which prevents the system from running wild by generating an intermittent reset pulse
during system mis-operation.
Features
1. Accurate voltage drop detection voltage
1. Low battery detection
3.4V3%
2. Power supply voltage detection
3.2V3%
3. Detection voltage error
0.2V20mV 1-2
4. Hysteresis Both
50mV typ.
2. Watchdog function stop pin (can be made to function only as reset IC during V
CC
rise)
3. Low current consumption
150A typ.
Package
SOP-8C (MM1135XF, MM1136XF)
Series Table
Applications
1. 3V cordless telephones
2. Various types of small, handy equipment
*
C
T
=0.02F
T
PR
: Reset hold time during V
CC
rise
T
WD
: Timer monitoring time
T
WR
: Reset time
V
SLB
: Battery check detection voltage
V
SLR
: Reset detection voltage
MITSUMI
System Reset (with built-in watchdog timer) MM1135, MM1136
Pin Assignment
1
4
3
2
8
5
6
7
SOP-8C
1
TC
2
BC (RESET
----------------------------------------------------------------------------------------
)
3
CK
4
GND
5
V
CC
6
RCT
7
V
S
8
RESET
----------------------------------------------------------------------------------------
Pin Description
Pin No.
Pin name
Function
1
TC
T
WD
, T
WR
, T
PR
time setting pins.
2
BC (RESET
----------------------------------------------------------------------------------------
)
Battery check output pin (RESET low level output) for 3.4V
3
CK
Clock input pin
4
GND
GND pin
5
V
CC
Power supply voltage input pin
6
RCT
Watchdog timer stop pin
Operation OPEN, Stop connect to GND
7
V
S
Detection voltage fine adjustment pin
8
RESET
----------------------------------------------------------------------------------------
Reset output pin (low output)
Block Diagram
MITSUMI
System Reset (with built-in watchdog timer) MM1135, MM1136
Absolute Maximum Ratings
Item
Symbol
Rating
Units
Power supply voltage
V
CC
max.
-0.3~+7
V
Voltage applied to input pin
V
IN
-0.3~V
CC
+0.3 ( <
= +7)
V
Voltage applied to output pin
V
OUT
-0.3~V
CC
+0.3 ( <
= +7)
V
Allowable loss
Pd
450
mW
Storage temperature
T
STG
-40~+125
C
Recommended Operating Conditions
Item
Symbol
Rating
Units
Power supply voltage
V
CC
+2.5~+6.5
V
RESET
--------------------------------------------------
sync current
I
OLR
0~1.5
mA
BC sync current
I
OLC
0~1.5
mA
Clock input high level voltage
V
CKH
1.4<
V
Clock input low level voltage
V
CKL
<0.4
V
Clock monitoring time setting
T
WD
1~1000
mS
Clock rise and fall times
t
RCK
, t
FCK
<100
S
Power supply voltage rise times
t
RVCC
100<
S
Power supply voltage fall times
t
FVCC
50<
S
TC pin capacitance
C
T
0.002~2
F
Operating temperature
T
OP
-25~+75
C
MITSUMI
System Reset (with built-in watchdog timer) MM1135, MM1136
Electrical Characteristics
(Except where noted otherwise, Ta=25C, Vcc=3.8V)
Item
Symbol Measurement
conditions
Min. Typ. Max. Units
Consumption current
I
CC
No load
200
280
A
RESET detection voltage
V
SLR
V
CC
: High Low
RCT : GND, V
TC
=OPEN
3.10
3.20
3.30
V
Detection voltage
V
SR
0.01 0.05 %/
C
temperature coefficient R
T
Hysteresis voltage R
V
HYSR
V
CC
: Low High
25
50
100
mV
RCT : GND, V
TC
=OPEN
BC detection voltage
V
SLB
V
CC
: High Low, R
LB
=10k
3.30
3.40
3.50
V
Detection voltage
V
SB
0.01 0.05 %/
C
temperature coefficient B
T
Hysteresis voltage B
V
HYSB
V
CC
: Low High, R
LB
=10k
25
50
100
mV
Detection voltage difference
V
SL
V
SL
=V
SLB
-V
SLR
0.18
0.20
0.22
V
CK input threshold
V
TH
0.8
1.2
2
V
CK input current
I
IH
V
CK
=3.8V
0
1
A
I
IL
V
CK
=0.0V
-15
-6
-2
Output voltage RH
V
OHR
I
RESET
---------------------------------------------------
=-5A
3.0
3.4
V
Output voltage BH
V
OHB
R
LB
=10k
3.2
3.6
V
Output voltage RL
V
OLR
I
RESET
---------------------------------------------------
=1mA, V
CC
=3.0V
0.3
0.5
V
Output voltage BL
V
OLB
I
BC
=5mA, V
CC
=3.0V
0.3
0.5
V
Output sync current R
I
OLR
V
RESET
---------------------------------------------------
=0.5V, V
CC
=3.0V
1
2
mA
Output sync current B
I
OLB
V
BC
=0.5V, V
CC
=3.0V
5
10
mA
Output source current R
I
OHR
V
RESET
---------------------------------------------------
=3.4V
8
15
A
C
T
charge current
I
CT
1
V
TC
=1.0V during watchdog timer operation -0.48 -0.24 -0.16
A
I
CT
2
V
TC
=1.0V during power ON reset operation -0.48 -0.24 -0.16
A
Minimum operating power supply
V
RESET
---------------------------------------------------
=0.4V
voltage to ensure RESET
-----------------------------------------------
V
CC
I
RESET
---------------------------------------------------
=0.1mA
0.8
1.0
V
MITSUMI
System Reset (with built-in watchdog timer) MM1135, MM1136
V
CC
input pulse width
8
T
PI
S
CK input pulse width
T
CKW
3
S
CK input cycle
T
CK
20
S
Watchdog timer monitoring time
*
1
T
WD
C
T
=0.02F
50
100
150
mS
Watchdog timer
reset time
*
2
T
WR
C
T
=0.02F
1
2
3
mS
Reset hold time for
power supply rise
*
3
T
PR
C
T
=0.02F
50
100
150
mS
RESET
------------------------------------------
delay time
t
PDR
V
CC
: High Low, R
LR
=10k
, C
LR
=15pF
10
S
BC delay time
t
PDB
V
CC
: High Low, R
LB
=4.7k
, C
LB
=15pF
10
S
RESET
------------------------------------------
rise time
t
RR
R
LR
=10k
, C
LR
=15pF
10
S
RESET
------------------------------------------
fall time
t
FR
R
LR
=10k
, C
LR
=15pF
2
S
BC rise time
t
RB
R
LB
=4.7k
, C
LB
=15pF
10
S
BC fall time
t
FB
R
LB
=4.7k
, C
LB
=15pF
2
S
V
CC
3.8V
2.8V T
PI
CK
T
CKW
or
CK
T
CK
Notes:
*
1 Monitoring time is the time from the last pulse (negative edge) of the timer clear clock pulse until reset
pulse output.
In other words, reset output is output if a clock pulse is not input during this time.
*
2 Reset time means reset pulse width. However, this does not apply to power ON reset.
*
3 Reset hold time is the time from when V
CC
exceeds detection voltage (V
SHR
) during power ON reset until
reset release (RESET
-----------------------------------------------------
output high).
*
4 Watchdog timer monitoring time (T
WD
), watchdog timer reset time (T
WR
) and reset hold time (T
PR
) during
power supply rise can be changed by varying C
T
capacitance. The times are expressed by the following
formulae.
T
PR
(mS)
.
=. 5000 C
T
(F)
T
WD
(mS)
.
=. 5000 C
T
(F)
T
WR
(mS)
.
=. 100 C
T
(F)
Example : When C
T
=0.02F
T
PR
.
=. 100mS
T
WD
.
=. 100mS
T
WR
.
=. 2mS
*
5 T
WD
can be varied by placing a resistor (1MEG
or more) between the RCT pin and V
CC
.
*
6 The voltage range when measuring output rise and fall time is 10~90%.
*
7 V
CC
rise time should be 100S or more, and fall time should be 50S or more.
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