M48TMH1 STMICROELECTRONICS [STMicroelectronics], M48TMH1 Datasheet - Page 2

• Manufacturer Part Number: M48TMH1
• Description: 5V PC REAL TIME CLOCK
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M48T86
Figure 2. DIP Connections
Table 1. Signal Names
2/23
AD0-AD7
E
R/W
DS
AS
RST
RCL
MOT
SQW
IRQ
V
V
NC
CC
SS
MOT
V SS
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
NC
NC
1
2
3
4
5
6
7
8
9
10
11
12
Multiplexed Address/Data Bus
Chip Enable Input
Write Enable Input
Data Strobe Input
Address Strobe Input
Reset Input
RAM Clear Input
Bus Type Select Input
Square Wave Output
Interrupt Request Output
Supply Voltage
Ground
Not Connected Internally
M48T86
AI01641
24
23
22
21
20
19
18
17
16
15
14
13
V CC
SQW
NC
RCL
NC
IRQ
RST
DS
NC
R/W
AS
E
Figure 3. SOIC Connections
DESCRIPTION
The M48T86 is an industry standard real time
clock (RTC).The M48T86 is composed of a lithium
energy source, quartz crystal, write-protection cir-
cuitry, 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
SOIC. Functions available to the user include a
non-volatile time-of-day clock, alarm interrupts, a
one-hundred-year clock with programmable inter-
rupts, 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 con-
nection to a separate SNAPHAT housing contain-
ing 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 sur-
face-mounting. The SNAPHAT housing is keyed
to prevent reverse insertion.
The SOIC and battery packages are shipped sep-
arately in plastic anti-static tubes or in Tape & Reel
form.
MOT
AD0
AD1
AD2
AD3
AD4
AD5
AD6
AD7
V SS
V SS
NC
NC
NC
1
2
3
4
5
6
7
8
9
10
11
12
13
14
M48T86
AI01642
28
27
26
25
24
23
22
21
20
19
18
17
16
15
NC
V CC
SQW
NC
RCL
NC
IRQ
RST
DS
NC
R/W
AS
E
NC