Appendix D. Power Supply; Power Supplies; Rcm3750 - Rabbit RabbitCore User Manual

Appendix D provides information on the current requirements
of the RCM3750, and includes some background on the chip
select circuit used in power management.
D.1 Power Supplies
Power is supplied from the motherboard to which the RCM3750 is connected via header
J1.
D.1.1 RCM3750
The RCM3750 has an onboard +3.3 V linear power regulator that provides the +3.3 V
supply to operate the microprocessor-related circuitry of the RCM3750. Figure D-1 shows
the power-supply circuit.
J1
VBAT_EXT
37
External
Battery
38
39
40
The RCM3750 requires a regulated 4.75 V to 5.25 V DC power source. An RCM3750 with
no loading at the outputs operating at 22.1 MHz typically draws 175 mA when the Ethernet
connection is active.
User's Manual
A
PPENDIX
RCM3750 LINEAR POWER REGULATOR
1.5 W
+V
10 nF
Figure D-1. RCM3750 Power Supply
D. P
OWER
LP8345/
MIC5209
U7/U4
10 µF
10 µF
S
UPPLY
+3.3 V
10 nF
157