m48t201v STMicroelectronics, m48t201v Datasheet - Page 14

• Manufacturer Part Number: m48t201v
• Description: 5.0 Or 3.3v Timekeeper Supervisor
• Manufacturer: STMicroelectronics

2.4
14/35
Table 4.
1. Valid for Ambient Operating Temperature: T
2. C
3. If E goes low simultaneously with W going low, the outputs remain in the high impedance state.
Data retention mode
With valid V
or WRITE cycles. Should the supply voltage decay, the M48T201Y/V will automatically
deselect, write protecting itself (and any external SRAM) when V
(max) and V
registers via the E signal. At this time, the Reset pin (RST) is driven active and will remain
active until V
manner by forcing E
remain at this level as long as V
below the level of the battery (V
SNAPHAT
External RAM is also powered by the SNAPHAT battery. All outputs except G
RST, IRQ/FT and V
100µA of current to the attached memory with less than 0.3V drop under this condition. On
power up, when V
by inhibiting E
page
t
t
WHQX
WLQZ
Symbol
t
t
t
t
t
noted).
t
t
t
t
t
t
t
t
WLWH
WHDX
WHAX
DVWH
AVWH
AVWL
EHDX
ELEH
EHAX
DVEH
AVEH
AVAV
AVEL
L
29).
= 5pF
(2)(3)
(2)(3)
®
CC
WRITE Cycle Time
Address Valid to WRITE Enable Low
Address Valid to Chip Enable Low
WRITE Enable Pulse Width
Chip Enable Low to Chip Enable High
WRITE Enable High to Address
Transition
Chip Enable High to Address Transition
Input Valid to WRITE Enable High
Input Valid to Chip Enable High
WRITE Enable High to Input Transition
Chip Enable High to Input Transition
WRITE Enable Low to Output High-Z
Address Valid to WRITE Enable High
Address Valid to Chip Enable High
WRITE Enable High to Output
Transition
PFD
battery and the clock registers are maintained from the attached battery supply.
Write mode AC characteristics
CC
CON
applied, the M48T201Y/V can be accessed as described above with READ
returns to nominal levels. External RAM access is inhibited in a similar
(min). This is accomplished by internally inhibiting access to the clock
CC
. The RST signal also remains active during this time (see
OUT
CON
returns to a nominal value, write protection continues for 200ms (max)
, become high impedance. The V
Parameter
to a high level. This level is within 0.2V of the V
CC
BAT
(1)
remains at an out-of-tolerance condition. When V
), power input is switched from the V
A
= 0 to 70°C; V
CC
Min
70
45
50
25
25
55
55
M48T201Y
0
0
0
0
0
5
0
= 4.5 to 5.5V or 3.0 to 3.6V (except where
–70
OUT
Max
20
pin is capable of supplying
CC
falls between V
Min
85
55
60
30
30
65
65
M48T201V
0
0
0
0
0
0
5
CC
BAT
–85
pin to the
. E
Figure 14 on
Max
CON
25
CON
, E
will
PFD
CC
CON
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
falls
,