m48t86 STMicroelectronics, m48t86 Datasheet - Page 6

• Manufacturer Part Number: m48t86
• Description: 5v Pc Real Time Clock
• Manufacturer: STMicroelectronics

Summary description
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The M48T86 is an industry standard Real Time Clock (RTC). The M48T86 is composed of a
lithium energy source, quartz crystal, write protection circuitry, and a 128-byte RAM array.
This provides the user with a complete subsystem packaged in either a 24-pin DIP
CAPHAT™ or 28-pin SNAPHAT
volatile time-of-day clock, alarm interrupts, a one-hundred-year clock with programmable
interrupts, square wave output, and 128 bytes of non-volatile static RAM.
The 24-pin, 600mil DIP CAPHAT houses the M48T86 silicon with a quartz crystal and a
long-life lithium button cell in a single package.
The 28-pin, 330mil SOIC provides sockets with gold plated contacts at both ends for direct
connection to a separate SNAPHAT
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 packages are shipped separately in plastic anti-static tubes or in
Tape & Reel form.
For the 28-lead SOIC, the battery/crystal package part number is “M4T28-BR12SH” (see
Table 20 on page
Figure 1.
Logic diagram
34).
AD0-AD7
MOT
RST
RCL
R/W
DS
AS
E
®
SOIC. Functions available to the user include a non-
8
®
housing containing the battery and crystal. The
V CC
V SS
M48T86
SQW
IRQ
AI01640