DS-72-34 Datasheet, PDF (17/18 Pages) Cymbet Corporation – I2C Real-Time Clock/Calendar with Integrated Backup Power

Preliminary
CBC34803 EnerChip™ RTC
10. The test engineer has the freedom to choose a point on the discharge curve that falls within the
parameters of test throughput and equipment measurement capability. In order for the EnerChip to be
considered as meeting the gross functional test specification, the voltage on the VCHG/VEC pin must be
above the value indicated by whichever line is chosen as the reference line.
11. Data at two temperatures is shown in order to encompass the range of anticipated factory test floors. Note
the influence of temperature on the EnerChip test discharge voltage when setting the test specification
pass/fail limits.
EnerChip Charge-Discharge Profiles for Setting Post-Assembly Test Limits
4.5
75K Ohm Load, 20 Degrees C
75K Ohm Load, 30 Degrees C
4.0
806K Ohm Load, 30 Degrees C
806K Ohm Load, 20 Degrees C
3.5
3.0
2.5
2.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Charge-Discharge Time (seconds)
Figure 7: Voltage Determination on the VCHG/VEC Pin
CBC34803 Internal Battery Backup Verification: Optional Board/System Level Test. ⁽¹⁾
Warning: Board level reflow/rework is not permitted if the following procedure is used.
The following test is normally used in the prototype testing phase as this test may take 10-15 minutes to
perform which is typically unsuitable for high speed in-circuit testing.
1. Power up board or system.
2. Ensure that CBC34803 EN pin 15 is asserted and VDD is > 2.5 volts.
3. Allow battery to charge for several minutes.
4. Program device to be battery-backed.
5. Remove power for at least several seconds to one minute.
6. Power up board or system.
7. Read device formerly under battery-backed operation.
8. Verify device contents.
Notes:
(1) _{This test does not verify the actual capacity of the integrated battery. In order to verify actual capacity, the}
device must be charged for at least one hour and then provide RTC power holdover until battery cut-off occurs.
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DS-72-34 V.20

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