<MFT> Preliminary RT8H042C *This is tentative specification. OUTLINE DRAWING RT8H042C is composed by NPN transistors, PNP transistors and resistors. This product has the reset function, and controls the backup function of the memory of SRAM and the microcomputer (internal organs RAM) 2.8±0.1 0.65±0.2 1.50±0.1 0.65±0.2 1.9±0.1 0.95±0.05 1.1±0.1 0.81 when the down of power and the power supply are abnormal. At the same time, RAM is switched from the main power supply to the backup power supply, the signal 2.80±0.2 ――― The reset signal（RES） is output to the microcomputer Unit：mm ① ⑥ ② ⑤ ③ ④ 0.33±0.05 DESCRIPTION ――― is switched to the backup circuit. 0～0.1 FEATURES 1.2±0.01 （C S ）that becomes a stand-by state is output, and RAM ●Miniaturization of a set. ●Detecting voltage（Power supply watch voltage） Standard：1.23V ――― ●Chip selection signal output（C S ） 6 ――― 5 4 ●Reset output（RES） Pin layout ――― APPLICATION 042 ・ Backup of memories of 3V faction microcomputer systems such as electronic office equipment, industrial equipment, and home electrical appliances ・ Control system of power supply where switch of external source and battery like SRAM board with built-in backup function is needed １ 2 3 ①C S ②CT ③R ④VIN ⑤GND ――― ⑥RES BLOCK DIAGRAM VIN コンパレーター Comparator R - Reset circuit リセット回路 + CS 遅延回路 Delay circuit RES CT GND 110428 <MFT> Preliminary RT8H042C *This is tentative specification. ABSOLUTE MAXIMUM RATINGS (Ta＝25℃) Symbol Parameter VIN Pd Kθ Tj Tstg Operating supply voltage range Internal power dissipation Thermal derating Junction temperature Storage temperature Topr Operating temperature Test conditions Ratings Unit (keep dry) 12 200 1.6 150 －40～150 V mW mW/℃ ℃ ℃ (keep dry) －20～75 ℃ Ta≧25℃ ELECTRICAL CHARACTERISTIC (Ta=25℃,VCC=3V unless otherwise noted.) Symbol Parameter VIN Operating supply voltage range Test conditions Min Designed value Typ Max Unit ２ - 10 V - 700 1050 uA 1.18 1.23 1.28 V 50 104 200 mV 0.65 1.32 2 V - - 0.3 V - - VIN V - - 0.5 V - - VIN V - - 0.5 V 9.0 18.0 27.0 ms - - 0.5 uA ――― IIN Circuit current R E S -VIN：10kΩｐｕｌｌｕｐ ―― CS ：10ｋΩ,3Vpullup，R：0V ――― VRTH R threshold voltage R：H⇒L R E S -VIN：10kΩｐｕｌｌｕｐ ―― CS ：10ｋΩ,3Vpullup,CT：OPEN Hysteresis R：H⇒L ,R E S -VIN：10kΩｐｕｌｌｕｐ ―― CS ：10ｋΩ,3Vpullup ――― ⊿VRTH CTH CTL RRESL RRESH CSH CSL Output voltage （Terminal CT in level HI） ――― R:2V,R E S -VIN：10kΩｐｕｌｌｕｐ ―― CS ：10ｋΩ,3Vpullup ――― Output voltage （Terminal CT in level Low） R：1V, R E S -VIN：10kΩｐｕｌｌｕｐ ―― CS ：10ｋΩ,3Vpullup Output voltage R：2V, R E S -VIN：10kΩｐｕｌｌｕｐ ―― CS ：10ｋΩ,3Vpullup ――― （RES in level Low） Output voltage ――― （RES in level HI） Output voltage ―― （CS in level HI） Output voltage ―― （CS in level Low） ――― ――― R E S ：1mA（SINK) R：1V,CＳ：10ｋΩ,3Vpullup ――― R：1V,R E S -VIN：10kΩｐｕｌｌｕｐ ―― CS ：10ｋΩ,3Vpullup ―― CS ：1mA（SINK) ――― R：2V,R E S -VIN：10kΩｐｕｌｌｕｐ ――― TPD Delay time CSLEAK CS leak current （VIN in level Low） ―― R：L⇒H ,R E S -VIN：10kΩｐｕｌｌｕｐ ―― CS ：10ｋΩ,3Vpullup,CT：0.047uF ――― R E S -VIN：10kΩｐｕｌｌｕｐ ―― R：LOW（１V)， CS ：10ｋΩ,3Vpullup Delay time＝3.83 x 105 x Ct 110428 Preliminary <MFT> RT8H042C *This is tentative specification. APPLICATION CIRCUIT EXAMPLES Protective Resistor Recommended parts ISA１２３５AC1 Battery：3V 110428 6-41 Tsukuba, Isahaya, Nagasaki, 854-0065 Japan Keep safety first in your circuit designs! ·ISAHAYA Electronics Corporation puts the maximum effort into making semiconductor products better and more reliable, but there is always 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) placement of substitutive, auxiliary, (2) use of non-farmable material or (3) prevention against any malfunction or mishap. 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