M48T18数据手册集成电路（IC）的实时时钟规格书PDF

描述 Description

The M48T08/18/08Y TIMEKEEPER®RAM is an 8 K x 8 non-volatile static RAM and real-time 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”.

特性 Features

• 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 protect VPFD= 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

简介

M48T18属于集成电路（IC）的实时时钟。由制造生产的M48T18实时时钟实时时钟 (RTC) 为几乎所有需要保持精确时间的电子设备提供时间和/或日期信息。时钟类型有二进制计数器、时钟/日历/监控器、历时计时器、幻时钟芯片、便携式系统控制器、温度记录器、时间事件记录器和计时器时钟外设。其包含 2 B 至 2 MB 不等的存储器，接口选项有 I2C、并行、串行、SPI、1 线式、2 线式、3 线式和 4 线式。