M48T59 ST Microelectronics, M48T59 Datasheet - Page 5

• Manufacturer Part Number: M48T59
• Description: 64 Kbit 8Kb x8 TIMEKEEPER SRAM
• Manufacturer: ST Microelectronics

Table 8. Power Down/Up AC Characteristics
(T
Note: 1. V
Figure 5. Power Down/Up Mode AC Waveforms
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 bat-
tery/crystal package (i.e. SNAPHAT) part number
is "M4T28-BR12SH" or “M4T32-BR12SH”.
Caution: Do not place the SNAPHAT battery/crys-
tal top in conductive foam, as this will drain the lith-
ium button-cell battery.
As Figure 3 shows, the static memory array and
the quartz controlled clock oscillator of the
M48T59/59Y/59V are integrated on one silicon
chip.
A
Symbol
t
REC
t
= 0 to 70 °C or –40 to 85 °C)
t
FB
F
t
t
2. V
3. t
PD
t
RB
R
(1)
(2)
es V
(3)
REC
PFD
PFD
V CC
V PFD (max)
V PFD (min)
V SO
RST
INPUTS
OUTPUTS
PFD
(min) = 20ms for industrial temperature grade 6 device.
(max) to V
(min) to V
E or W at V
V
V
V
V
V
(min).
PFD
PFD
PFD
SS
PFD
to V
(min) to V
(max) to V
(min) to V
(max) to RST High
SS
PFD
PFD
fall time of less than t
(PER CONTROL INPUT)
(min) fall time of less than t
tPD
IH
(min) V
before Power Down
VALID
PFD
SS
RECOGNIZED
PFD
tF
V
(max) V
CC
CC
(min) V
Fall Time
Rise Time
Parameter
FB
CC
CC
may cause corruption of RAM data.
Rise Time
Fall Time
tFB
F
may result in deselection/write protection not occurring until 200µs after V
The two circuits are interconnected at the upper
eight memory locations to provide user accessible
BYTEWIDE™ clock information in the bytes with
addresses 1FF8h-1FFFh. The clock locations
contain the century, year, month, date, day, hour,
minute, and second in 24 hour BCD format (except
for the century). Corrections for 28, 29 (leap year),
30, and 31 day months are made automatically.
Byte 1FF8h is the clock control register. This byte
controls user access to the clock information and
also stores the clock calibration setting.
DON'T CARE
tDR
HIGH-Z
M48T59/Y
M48T59V
tRB
M48T59, M48T59Y, M48T59V
Min
300
150
10
40
10
0
1
tR
(PER CONTROL INPUT)
Max
200
tREC
RECOGNIZED
VALID
AI03258
Unit
ms
µs
µs
µs
µs
µs
µs
CC
pass-
5/21