ST M48T18-100PC1

时钟/日历闰年，监视计时器

Overview

The M48T08/18/08Y TIMEKEEPER® RAM is an 8 K x 8 non-volatile static RAM and realtime clock which is pin and function compatible with the DS1643. The monolithic chip is available in two special packages to provide a highly integrated battery-backed memory and real-time clock solution.The M48T08/18/08Y is a non-volatile pin and function equivalent to any JEDEC standard 8 K x 8 SRAM. It also easily fits into many ROM, EPROM, and EEPROM sockets, providing the non-volatility of PROMs without any requirement for special WRITE timing or limitations on the number of WRITEs that can be performed.The 28-pin, 600 mil DIP CAPHAT™ houses the M48T08/18/08Y silicon with a quartz crystal and a long-life lithium button cell in a single package. The 28-pin, 330 mil SOIC provides sockets with gold-plated contacts at both ends for direct connection to a separate SNAPHAT® housing containing the battery and crystal. The unique design allows the SNAPHAT® battery package to be mounted on top of the SOIC package after the completion of the surface mount process. Insertion of the SNAPHAT® housing after reflow prevents potential battery and crystal damage due to the high temperatures required for device surface-mounting. The SNAPHAT® housing is keyed to prevent reverse insertion.The SOIC and battery/crystal packages are shipped separately in plastic anti-static tubes or in tape & reel form. For the 28-lead SOIC, the battery/crystal package (e.g., SNAPHAT®) part number is “M4T28-BR12SH” or “M4T32-BR12SH”.■ Integrated ultra low power SRAM, real-time clock, power-fail control circuit, and battery■ BYTEWIDE™ RAM-like clock access■ BCD coded year, month, day, date, hours, minutes, and seconds■ Typical clock accuracy of ±1 minute a month, at 25 °C■ Automatic power-fail chip deselect and WRITE protection■ WRITE protectVPFD = power-fail deselect voltage):– M48T08: VCC = 4.75 to 5.5 V; 4.5 V ≤ VPFD ≤ 4.75 V– M48T18/T08Y: VCC = 4.5 to 5.5 V; 4.2 V ≤ VPFD ≤ 4.5 V■ Software controlled clock calibration for high accuracy applications■ Self-contained battery and crystal in the CAPHAT™ DIP package■ Packaging includes a 28-lead SOIC and SNAPHAT® top (to be ordered separately)■ SOIC package provides direct connection for a snaphat top which contains the battery and crystal■ Pin and function compatible with DS1643 and JEDEC standard 8 K x 8 SRAMs■ RoHS compliant– Lead-free second level interconnect

Features

High-performance signal processor for communications, graphics, and imaging applications

Super Harvard Architecture

    - 4 independent buses for dual data fetch, instruction fetch, and nonintrusive I/O

32-bit IEEE floating-point computation units—multiplier, ALU, and shifter

Dual-ported on-chip SRAM and integrated I/O peripherals—a complete system-on-a-chip

Integrated multiprocessing features

Applications

Automotive 

Hybrid, electric & powertrain systems 

Industrial 

Electronic point of sale (EPOS) 

Enterprise systems 

Datacenter & enterprise computing