＜MFT＞

RT8H062E
WATCH DOG TIMERDESCRIPTION
RT8H062E is a semiconductor integrated circuit which isdesigned for System Reset to detect +3.3V、+5V power supply.
This MFT keeps the operation of micro computer watching.
The system circuit current at normal state is low consumption
type of 0.6mA(Typical).

OUTLINE DRAWINGFEATURES● Miniaturization of a set● Watch Dog Timer● Variable power on reset voltage● Low consumption type：0.6mA（Typ,VCC=3.3V）● Wide range of power supply：VCC（MAX）=10V● Open collector outputAPPLICATION● Microcomputer Systems

Unit：mm
PIN CONFIGURATION①②③④RECOMMENDED OPERATING CONDITIONS● Supply voltage：3.3V、5V⑧⑦⑥⑤①Delay
②WD
③GND
④R

⑧VCC
⑦TC
⑥OUT
⑤C

BLOCK DIAGLAM OF MFT , APPLICATION CIRCUIT EXAMPLES

CDelayDelayTC

CTC

VCC

OUT
R

Delay

WDTGND

WDC

CC110805（1／4）

ISAHAYA ELECTRONICS CORPORATION

＜MF

T＞

RT8H062E
WATCH DOG TIMERTERMINAL FUNCTION
Terminal No.

Undecided

SymbolVCCRWDCTC
Delay
OUT
GND

Function
Suply voltage terminal
To change vcc detective voltage terminal
Watch dog input terminal
To set abnormal high section of watch dog input terminal
To set watch dog time terminal
To set power on reset time. Connection capacity terminal
If input abnormal watch dog signal, then it output reset signal.
Grand teerminal

ABSOLUTE MAXIMUM RATINGS (Ta＝25℃)
SymbolVCC
VIN
IOUT
PdToprTstg

Ratings
10-0.3～VCC
10200-20～+75-40～+150

Parameter
Supply voltage
Input voltage（WD,C,TC,Delay）
Output current（OUT）
Internal power dissipation
Operating temperature
Storage temperature

UnitVVmAmW℃℃

ELECTRICAL CHARACTERISTIC (Ta=25℃,VCC=3.3V unless otherwise noted.)
SymbolICC
VsH
VsL
VWDthIWDIC
VTCthH
VTCthL
VDthIDelay
VOsat1
VOsat2

Parameter

Test conditions

Circuit current
VCC detective voltage at High OUT=VCC-100kΩ、OUT：L→H
VCC detective voltage at Low OUT=VCC-100kΩ、OUT：H→L

C：L→H
WD=3V
WD=3V、C=0.3V
Threshold voltage of TC HIGH OUT=VCC-100kΩ、OUT：H→L
Threshold voltage of TC LOW OUT=VCC-100kΩ、OUT：L→H
Threshold voltage of Delay OUT=VCC-100kΩ、OUT：L→HCharge current of Delay Delay=0V
OUT saturation voltage1 VCC=1.2V、I=1mA
OUT saturation voltage2 VCC=3V、TC=3V、I=1mA
Threshold voltage of WD
WD input current
Output current CMin
360
2.73
2.62
80

Designed value
Typ
600
2.87
2.76
1.3
160
20
1.5
1.1
1.2
5
0.12
0.10

Max
840
3.01
2.90
320

0.50
0.50

110805（2／4）

ISAHAYA ELECTRONICS CORPORATION

UnituA
V
V
V
uA
uA
V
V
V
uA
V
V

＜MF

T＞

RT8H062E
WATCH DOG TIMER

TIMING DIAGRAM
VCC

VsH

VsL

VTCthHTCVTCthLtRSTWDtDOUT
OUTtWD

123456789NOTES
1．The VCC rises up to detective voltage(VsH), then reset is released.
2．OUT terminal(Open collector) generate High signal, after tDOUT time decided from capacity at Delay terminal.
Charge of TC begins.
tDOUT [s]≒Cdelay[F]×1.2[V]÷5E-6[A]3．This MFT watch WD signal from when TC rises up from VTCthL to VTCthH. If no signal input WD, OUT terminal generate Low signal.
tWD[s]≒0.236×C TC [F]×R[Ω]4．When TC falls to VTCthL, OUT terminal generate High signal.
tRST [s]≒100×C TC [F]
5．Due to the power failure etc, VCC falls to VsL, OUT terminal generate Low signal.
6．VCC rises up to VsH, OUT terminal generate High signal (if no Cdelay capacity).
7．If normal clock signal is entered in twd time, TC terminal is decharged. And if TC terminal falls to VTCthL, TC begins chaerge.
8．If no signal is entered in twd time, OUT terminal generate Low signal.
9．When VCC falls to VsL, OUT terminal generate Low signal.
*About C terminal
Please connect capacity C terminal-GND terminal always. This capacity is always necessary for detected edge of WD signal
And, for detected abnormal state of WD's high fixation, This capacity can detect normal time of WD's high fixation.
twdh [s]≒30000×C C[F]When High signal is entered in WD terminal, twdh[s] or more, TC terminal begins charge, and begin operate 3．.

110805（3／4）

ISAHAYA ELECTRONICS CORPORATION

＜MFT＞

RT8H062E
WATCH DOG TIMER

About VCC detective voltage (R terminal)
VCC detective voltage

VsH
VsL

At Open
2.87V
2.76V

At 3.3kΩ pull down

4.15V
3.98V

If change Radj, VCC detective voltage is variable.

VCC

VsH≒(1+17.5k/Combined resistance between point A～GND )×1.32V

17.5kΩ
RRadj

15kΩ

VsL≒1+17.5k/Combined resistance between point A～GND )×1.25V

A

15kΩ
1.25V

THERMAL DERATING

POWER DISSIPATION Pd[ｍW]250200150100
5000255075100125150

AMBIENT TEMPERATURE Ta [℃]110805（4／4）

ISAHAYA ELECTRONICS CORPORATION

Keep safety first in your circuit designs!
·ISAHAYA Electronics Corporation puts the maximum effort into making semiconductor products better and more reliable, but there isalways the possibility that trouble may occur with them. Trouble with semiconductors may lead to personal injury, fire or property damage.
Remember to give due consideration to safety when making your circuit designs, with appropriate measures such as (1) placementof substitutive, auxiliary, (2) use of non-farmable material or (3) prevention against any malfunction or mishap.
Notes regarding these materials·These materials are intended as a reference to our customers in the selection of the ISAHAYA products best suited to the customerʼ sapplication; they don't convey any license under any intellectual property rights, or any other rights, belonging ISAHAYA or third party.
·ISAHAYA Electronics Corporation assumes no responsibility for any damage, or infringement of any third party's rights, originating in the useof any product data, diagrams, charts or circuit application examples contained in these materials.
·All information contained in these materials, including product data, diagrams and charts, represent information on products at the timeof publication of these materials, and are subject to change by ISAHAYA Electronics Corporation without notice due to product improvements
or other reasons. It is therefore recommended that customers contact ISAHAYA Electronics Corporation or an authorized ISAHAYA products
distributor for the latest product information before purchasing product listed herein.
·ISAHAYA Electronics Corporation products are not designed or manufactured for use in a device or system that is used under circumstances inwhich human life is potentially at stake. Please contact ISAHAYA Electronics Corporation or an authorized ISAHAYA products distributor whenconsidering the use of a product contained herein for any specific purposes, such as apparatus or systems for transportation, vehicular,medical, aerospace, nuclear, or undersea repeater use.
·The prior written approval of ISAHAYA Electronics Corporation is necessary to reprint or reproduce in whole or in part these materials.
·If these products or technologies are subject to the Japanese export control restrictions, they must be exported under a license fromthe Japanese government and cannot be imported into a country other than the approved destination. Any diversion or re-export contrary to
the export control laws and regulations of Japan and/or the country of destination is prohibited.
·Please contact ISAHAYA Electronics Corporation or authorized ISAHAYA products distributor for further details on these materials or
the products contained therein.

Aug.2016