DS3070W Maxim Integrated Products, DS3070W Datasheet - Page 17

• Manufacturer Part Number: DS3070W
• Manufacturer: Maxim Integrated Products

Surface-mount components minimize lead inductance,
which improves performance, and ceramic capacitors
tend to have adequate high-frequency response for
decoupling applications.
Care should be taken to avoid simultaneous access of
the SRAM and RTC devices (see Figure 4). Any chip-
enable overlap violates t
and unpredictable behavior.
The IRQ/FT and RST outputs are open drain, and there-
fore require pullup resistors to realize a high logic out-
put level. Pullup resistor values between 1kΩ and 10kΩ
are typical.
The DS3070W charges an ML battery to maximum
capacity in approximately 96 hours of operation when
V
its lifetime depends primarily on the V
The DS3070W can maintain data from a single, initial
charge for up to 2 years. Once recharged, this deep-
discharge cycle can be repeated for up to 20 times,
producing a worst-case service life of 40 years. More
typical duty cycles are of shorter duration, enabling the
DS3070W to be charged hundreds of times, and
extending the service life well beyond 40 years.
The DS3070W can be cleaned using aqueous-based
cleaning solutions. No special precautions are needed
when cleaning boards containing a DS3070W module.
Removal of the topside label violates the environmental
integrity of the package and voids the warranty of the
product.
Figure 4. SRAM/RTC Data Bus Control
CC
is greater than V
3.3V Single-Piece 16Mb Nonvolatile SRAM
CS
CE
Avoiding Data Bus Contention
Using the Open-Drain
TP
Battery Charging/Lifetime
Recommended Cleaning
. Once the battery is charged,
CCS
and can result in invalid
V
IH
and RST Outputs
____________________________________________________________________
t
CCS
CC
Procedures
duty cycle.
V
IRQ /FT
IH
Recommended Reflow Temperature
Profile
Note: All temperatures refer to topside of the package, mea-
sured on the package body surface.
Average ramp-up rate
(T
Preheat
- Temperature min (T
- Temperature max (T
- Time (min to max) (ts)
T
- Ramp-up rate
Time maintained above:
-
- Time (t
Peak temperature (T
Time within 5°C of actual peak
temperature (T
Ramp-down rate
Time 25°C to peak temperature
Smax
Temperature (T
L
to T
to T
PROFILE FEATURE
P
L
)
)
L
V
IH
P
)
L
)
P
t
Smin
CCS
Smax
)
)
)
V
IH
with Clock
Sn-Pb EUTECTIC
60 to 120 seconds
60 to 150 seconds
10 to 30 seconds
3°C/second max
6°C/second max
6 minutes max
ASSEMBLY
225 +0/-5°C
100°C
150°C
183°C
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