M41T315Y
M41T315V, M41T315W
Serial access phantom RTC supervisor
Not For New Design
Features
■
■
3.0V, 3.3V, or 5V operating voltage
Real-time clock keeps track of
tenths/hundredths of seconds, seconds,
minutes, hours, days, date of the month,
months, and years
Automatic leap year correction valid up to 2100
Automatic switch-over and deselect circuitry
Choice of power-fail deselect voltages:
(V
PFD
= power-fail deselect voltage)
– M41T315Y
(a)
: V
CC
= 4.5 to 5.5V
4.25V
≤
V
PFD
≤
4.50V
– M41T315V: V
CC
= 3.0 to 3.6V
2.80V
≤
V
PFD
≤
2.97V
– M41T315W: V
CC
= 2.7 to 3.3V
2.60V
≤
V
PFD
≤
2.70V
No address space required to communicate
with RTC
Provides nonvolatile supervisor functions for
battery backup of SRAM
Full
±
10% V
CC
operating range
Industrial operating temperature range (–40 to
+85°C)
Ultra-low battery supply current of 500nA (max)
Optional packaging includes A 28-lead SOIC
and SNAPHAT
®
top (to be ordered separately)
SNAPHAT package provides direct connection
for a snaphat top, which contains the battery
and crystal
RoHS compliant
– Lead-free second level interconnect
28
1
16
1
■
■
■
SO16 (MQ)
SNAPHAT (SH)
battery & crystal
■
■
■
■
■
■
■
SOH28 (MH)
■
a. Contact local ST sales office for availability.
November 2007
Rev 3
1/30
www.st.com
1
This is information on a product still in production but not recommended for new designs.
Contents
M41T315Y, M41T315V, M41T315W
Contents
1
2
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.1
2.2
Non-volatile supervisor operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Data retention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3
Clock operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.1
3.2
3.3
3.4
Clock register information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
AM-PM/12/24 mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Oscillator and reset bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Zero bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4
5
6
7
8
Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2/30
M41T315Y, M41T315V, M41T315W
List of tables
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Table 9.
Table 10.
Table 11.
Table 12.
Table 13.
Table 14.
Table 15.
Table 16.
Table 17.
Table 18.
Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Operating modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
AC electrical characteristics (M41T315Y). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
AC electrical characteristics (M41T315V/W) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
RTC register map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Ablolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
DC and AC measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
DC characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Crystal electrical characteristics (externally supplied) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Power down/up trip points DC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
SO16 - 16-lead plastic small outline (150 mils body width), package mechanical data . . . 23
SOH28 - 28-lead plastic small outline, package mechanical data . . . . . . . . . . . . . . . . . . . 24
SH - 4-pin SNAPHAT housing for 48mAh battery and crystal, package mechanical data . 25
SH - 4-pin SNAPHAT housing for 120mAh battery and crystal, package mechanical data 26
Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
SNAPHAT battery table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3/30
List of figures
M41T315Y, M41T315V, M41T315W
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
Figure 14.
Figure 15.
Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
16-pin SOIC connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
28-pin SOIC connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
M41T315Y/V/W to RAM/clock interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Read mode waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Write mode waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Comparison register definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Reset pulse waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
AC testing load circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Power down/up mode AC waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
SO16 - 16-lead plastic small outline, package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
SOH28 - 28-lead plastic small outline, package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
SH - 4-pin SNAPHAT housing for 48mAh battery and crystal, package mechanical data . 25
SH - 4-pin SNAPHAT housing for 120mAh battery and crystal, package outline . . . . . . . . 26
4/30
M41T315Y, M41T315V, M41T315W
Description
1
Description
The M41T315Y/V/W RTC Supervisor is a combination of a CMOS TIMEKEEPER
®
and a
nonvolatile memory supervisor. Power is constantly monitored by the memory supervisor. In
the event of power instability or absence, an external battery maintains the timekeeping
operation and provides power for a CMOS static RAM by switching on and invoking write
protection to prevent data corruption in the memory and RTC.
The clock keeps track of tenths/hundredths of seconds, seconds, minutes, hours, day, date,
month, and year information. The last day of the month is automatically adjusted for months
with less than 31 days, including leap year correction.
The clock operates in one of two formats:
●
a 12-hour mode with an AM/PM indicator;
a 24-hour mode
or
●
The nonvolatile supervisor supplies all the necessary support circuitry to convert a CMOS
RAM to a nonvolatile memory. The M41T315Y/V/W can be interfaced with RAM without
leaving gaps in memory.
The M41T315Y/V/W is supplied in a 28-lead SOIC SNAPHAT® package (which integrates
both crystal and battery in a single SNAPHAT top) or a-16 pin SOIC. The 28-pin, 330mil
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/crystal 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 also keyed to prevent reverse insertion.
The 28-pin 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 “M4TXX-BR12SH” (see
Table 17 on page 28).
Caution:
Do not place the SNAPHAT battery/crystal top in conductive foam, as this will drain the
lithium button-cell battery.
5/30
京公网安备 11010802033920号
EEWORLD
