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APPENDIX C. POWER SUPPLY
Appendix C provides information on the current requirements of the RCM4000, and includes some background on the chip select circuit used in power management.
C.1 Power Supplies
The RCM4000 requires a regulated 3.0 V – 3.6 V DC power source. The RabbitCore design presumes that the voltage regulator is on the user board, and that the power is made available to the RCM4000 board through header J2.
An RCM4000 with no loading at the outputs operating at 58.98 MHz typically draws 110 mA.
C.1.1 Battery-Backup Circuits
The RCM4000 does not have a battery, but there is provision for a
Header J2, shown in Figure
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| J2 |
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External | +3.3 V_IN | 1 | 2 | GND |
Battery |
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| VBAT_EXT | 7 | 8 |
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Figure C-1. External Battery Connections
at Header J2
A lithium battery with a nominal voltage of 3 V and a minimum capacity of 165 mA·h is recommended. A lithium battery is strongly recommended because of its nearly constant nominal voltage over most of its life.
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