M4T28-BR12SH1 STMicroelectronics, M4T28-BR12SH1 Datasheet - Page 10

• Manufacturer Part Number: M4T28-BR12SH1
• Description: IC SNAPHAT BATT/CRYSTAL 28-SOIC
• Manufacturer: STMicroelectronics

Specifications of M4T28-BR12SH1

• Battery Type: Li-(CF)
• Operating Supply Voltage: 0 V to 2.8 V
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Package / Case: SOIC-28
• Mounting Style: SMD/SMT
• Ic Function: Timekeeper (Battery & Crystal)
• Supply Voltage Range: 2.8V
• Operating Temperature Range: 0°C To +70°C
• Digital Ic Case Style: SNAPHAT
• No. Of Pins: 28
• Termination Type: SMD
• Rohs Compliant: Yes
• Filter Terminals: SMD
• External Depth: 14.99mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-3686-5

Operation modes
2.2
10/29
WRITE mode
The M48T35AV is in the WRITE mode whenever W and E are low. The start of a WRITE is
referenced from the latter occurring falling edge of W or E. A WRITE is terminated by the
earlier rising edge of W or E. The addresses must be held valid throughout the cycle. E or W
must return high for a minimum of t
to the initiation of another READ or WRITE cycle. Data-in must be valid t
end of WRITE and remain valid for t
cycles to avoid bus contention; however, if the output bus has been activated by a low on E
and G, a low on W will disable the outputs t
Figure 6.
Figure 7.
A0-A14
E
W
DQ0-DQ7
A0-A14
E
W
DQ0-DQ7
WRITE enable controlled, WRITE mode AC waveform
Chip enable controlled, WRITE mode AC waveforms
tAVEL
tAVEL
tAVWL
tAVWL
Doc ID 6845 Rev 8
tWLQZ
EHAX
WHDX
tAVWH
from chip enable or t
tAVEH
afterward. G should be kept high during WRITE
tWLWH
VALID
tAVAV
WLQZ
tAVAV
VALID
tELEH
after W falls.
tDVEH
tDVWH
DATA INPUT
DATA INPUT
tWHDX
WHAX
from WRITE enable prior
tEHDX
tWHQX
DVWH
tEHAX
tWHAX
prior to the
M48T35AV
AI00926
AI00927