DS1646-120 Maxim Integrated Products, DS1646-120 Datasheet - Page 6

• Manufacturer Part Number: DS1646-120
• Description: Real Time Clock
• Manufacturer: Maxim Integrated Products

Specifications of DS1646-120

• Function: Clock, Calendar, NV Timekeeping RAM
• Rtc Memory Size: 131072 B
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: Through Hole
• Rtc Bus Interface: Parallel
• Package / Case: eDIP
• Time Format: HH:MM:SS
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WRITING DATA TO RAM OR CLOCK
The DS1646 is in the write mode whenever
referenced to the latter occurring high to low transition of
throughout the cycle.
another read or write cycle. Data in must be valid t
afterward. In a typical application, the
active provided that care is taken with the data bus to avoid bus contention. If
transitioning low the data bus can become active with read data defined by the address inputs. A low
transition on
DATA RETENTION MODE
When V
read or write cycles. However, when V
protection occurs) the internal clock registers and RAM are blocked from access. This is accomplished
internally by inhibiting access via the
driven active low and will remain active until V
level of the internal battery supply, power input is switched from the V
clock activity, RAM, and clock data are maintained from the battery until V
level.
CC
is within nominal limits (V
WE
will then disable the outputs t
CE
or
WE
must return inactive for a minimum of t
CC
CE
OE
> 4.5 volts) the DS1646 can be accessed as described above with
CC
signal. At this time the power-fail output signal (
signal will be high during a write cycle. However,
WE
is below the power-fail point V
WEZ
CC
6 of 12
and
after
returns to nominal levels. When V
DS
CE
prior to the end of write and remain valid for t
WE
are in their active state. The start of a write is
WE
goes active.
and
CE
. The addresses must be held valid
CC
pin to the internal battery and
WR
CC
PF
prior to the initiation of
OE
is returned to nominal
(point at which write
is low prior to
CC
DS1646/DS1646P
falls below the
PFO
OE
) will be
can be
WE
DH