Apalis Carrier Board Design Guide
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Page | 63
3
Power Management
3.1 Power Signals
3.1.1
Digital Supply Signals
Apalis
Pin
Apalis
Signal Name
I/O
Type
Power
Rail
Description
10, 30, 36, 52, 58, 66, 78, 90,
102, 108
VCC
I
PWR
3.3V
Main power supply input for the module
9, 23, 29, 39, 45, 51, 57, 69,
75, 81, 93, 105, 111, 117, 129,
141, 147, 153, 165, 189, 199,
213, 219, 237, 241, 267, 285,
142, 182, 192, 206, 218, 226,
238, 244, 250, 256, 268, 280,
292, 298
GND
I
PWR
Common signal and power ground
174
VCC_BACKUP
I
PWR
3.3V
RTC supply, can be left unconnected if
internal RTC is not used
Table 38: Digital supply signals
3.1.2
Analogue Supply Signals
Apalis
Pin
Apalis
Signal Name
I/O
Type
Power
Rail
Description
314, 320
AVCC
I
PWR
3.3V
Power supply for the analogue part of the
module
303, 313, 304, 308
AGND
I
PWR
Ground for the analogue part of the module
Table 39: Analogue supply signals
The analogue power supply is used on the module for the analogue circuits. 3.3V needs to be
provided to this input even if the analogue interfaces are not used in the design. In this case, the
pins can be connected to the 3.3V digital supply for the module. For a better audio quality and
improved resistive touch performance, it is recommended that separate filters are added to the
analogue power supply rail. For the best quality, a separate power supply with linear voltage
regulator is recommended.
3.1.3
Power Management Signals
Apalis
Pin
Apalis
Signal Name
I/O Type
Power
Rail
Description
28
RESET_MICO#
I
CMOS
3.3V
Active low reset input
26
RESET_MOCI#
O
CMOS
3.3V
Active low reset output
24
POWER_ENABLE_MOCI O
CMOS
3.3V
Signal for the carrier board to enable the peripheral voltage rails
37
WAKE1_MICO#
I
CMOS
3.3V
Active low main module wake input signal - needs a pull-up
resistor on the baseboard if wake function is used
Table 40: Power management signals
To make the direction of the power management signals clear, the ending MICO or MOCI are
appended to the signal names. MICO is the abbreviation for “Module Input, Carrier board Output”
while MOCI stands for “Module Output, Carrier board Input”