Datasheet
Section 23 Electrical Characteristics 
Rev.5.00 Nov. 02, 2005 Page 428 of 500 
REJ09B0027-0500   
23.3.8  Power-On Reset Circuit Characteristics (Optional) 
Table 23.20  Power-On Reset Circuit Characteristics 
V
SS 
= 0.0 V, T
a
 = –20 to +75°C, unless otherwise indicated. 
Values 
Item Symbol 
Test 
Condition 
Min Typ Max Unit 
Pull-up resistance of RES pin R
RES
    100 150 —  kΩ 
Power-on reset start voltage* V
por
    — — 100 mV 
Note:  *  The power-supply voltage (Vcc) must fall below Vpor = 100 mV and then rise after 
charge of the RES pin is removed completely. In order to remove charge of the RES 
pin, it is recommended that the diode be placed in the Vcc side. If the power-supply 
voltage (Vcc) rises from the point over 100 mV, a power-on reset may not occur. 
23.4 Operation Timing 
t
OSC
V
IH
V
IL
t
CPH
t
CPL
t
CPr
OSC1
t
CPf
Figure 23.1 System Clock Input Timing 










