DS1227 Datasheet, PDF (20/20 Pages) Dallas Semiconductor – KickStarter Chip

DS1227
NOTES:
1. Applicable only when Boost mode operation is in effect.
2. Applicable only when Pass Through mode operation is in effect.
3. Valid when 2.5V < V_DCO < 5.0V.
4. Measured with Boost Mode operation in effect; I_CCO1 = I_CCO2 = I_CCO3 = I_CCO4 = 0. This value represents the
amount of current drawn by the DS1227 itself during and does not include current supplied on the I_CCO out-
puts nor does if boost operator includes inefficiencies of DC-to-DC conversion.
5. Input transition current on the INT/ACK pin is specified to indicate the amount of current required to switch the
pin from a high to a low or from a low to a high condition. Once the pin has switched states, then the leakage
current specification is applicable.
6. ON1 and RXIN have internal weak p-channel pull-up devices.
7. When BOOST operation is in effect, the total combined current supplied out of V_CCO1, V_CCO2, V_CCO3, and
V_CCO4 is limited by the V_DCI peak current.
8. Actual efficiency is dependent on external discrete component characteristics.
9. Battery replacement in the boost mode requires the discharge of the capacitor attached to V_DCO (pin 5). The
following, or similar, circuit is recommended (see Figure 11).
BATTERY DISCHARGE CIRCUIT Figure 11
BATTERY CHANGE
DETECTOR
TO BATTERY
V_DCO (PIN 5)
RB400D
+
100 µF
4M
TC7SU04F
2N7002
022698 20/20