RTC-72423

Real time clock module 4-bit REAL TIME CLOCK MODULE RTC-72421/ 72423 Built-in crystal unit allows adjustment-free efficient operation. ALE input terminal available for 8048, 8051, and 8085 series. 12/24 h clock switchover function and automatic leap year setting. Interrupt masking. 30 second adjustment function. Low current consumption and features a backup function. Actual size Specifications (characteristics) Absolute Max. rating Symbol Item VDD Power source voltage VI/O Input and output voltage Storage temperature TSTG Condition Ta=+25 °C Ta=+25 °C RTC-72421 RTC-72423 RTC-72421 Soldering condition TSOL RTC-72423 Specifications -0.3 to 7.0 GND -0.3 to VDD+0.3 -55 to +85 -55 to +125 Under +260 °C within 10 s (lead part) (package should be less than +150 °C) Terminal connection Unit V °C RTC-72421 18 17 16 15 14 13 12 11 10 Twice at under +260 °C within 10 s or under +230 °C within 3 min. 1 2 3 4 5 6 7 8 9 Operating range Item Operating voltage Operating temperature Data holding voltage CSI data holding time Operation restoring time Symbol VDD TOPR VDH tCDR tR Refer to the data holding timing RTC-72421 RTC-72423 Condition Specifications 4.5 to 5.5 -10 to 70 -40 to 85 2.0 to 5.5 2.0 Min. Unit V °C V µs RTC-72423 24 23 22 21 20 19 18 17 16 15 14 13 No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 72421 STD. P CS 0 ALE A0 A1 A2 A3 RD GND WR D3 D2 D1 D0 CS1 (VDD) (VDD) VDD 1 2 3 4 5 6 7 8 9 10 11 12 (VDD) and VDD are to have the same level of volt...