101-1006 Rabbit Semiconductor, 101-1006 Datasheet - Page 204

• Manufacturer Part Number: 101-1006
• Description: MODULE POWERCORE FLEX 3800
• Manufacturer: Rabbit Semiconductor

Specifications of 101-1006

• Module/board Type: MPU Core Module
• For Use With/related Products: RCM3800
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

The two preconfigured PowerCore models are built for use with a full-wave rectifier and
center-tapped AC transformer. Power may be supplied directly to the PowerCore module
via the locking connector at header J3:
• via pins 2, 4, and 6 (AC); note that center tap of the transformer is connected to ground
• via pins 2 and 3 (DC, unregulated)
Power may also be supplied to the PowerCore module from the motherboard to which the
PowerCore module is plugged in:
• via pins 1 and 2 of header J4 (AC); note that center tap of the transformer should be
• via pins 4 and 5 of header J4 (DC, unregulated)
The PowerCore module also provides for the regulated voltages to be output for use on the
motherboard or elsewhere:
• +5 V DC on pin 6, header J4 (connection to motherboard), and pin 1, header J3 (locking
• +3.45 V DC (+V) on pin 21, header J4 (connection to motherboard)
You can draw up to 550 mA from the +3.45 V supply, depending on the PowerCore
options and the operating temperature. If there is a +5 V regulator on the PowerCore
board, you can draw as much as 850 mA or 1850 mA from the +5 V supply, depending on
what options are actually installed on the PowerCore module, the input voltage to the
switching regulator, and the operating temperature. The current from the various power
supplies that is available for use on the motherboard or elsewhere is specified in Table A-1.
There is an additional design consideration for the switching power supply with regard to
AC ripple at 50 kHz or 150 kHz. The ripple can be reduced by adding additional filtering
capacitors on the motherboard or by using local filters where reduced ripple is required.
Ripple increases as more current is drawn from the power supply.
Ripple in the rectified AC can also be a particular concern for the half-wave rectifier
option. This ripple can be reduced by adding additional capacitance to the unregulated DC
between the DC+ line (from pin 4 of J4) and ground on the motherboard.
The operating life of electrolytic filter capacitors is reduced at higher temperatures and
with more ripple. For this reason it is important to use high-quality capacitors and to follow
standard engineering guidelines for ripple at higher operating temperatures to extend
capacitor life and to avoid premature failures.
If you plan to operate your PowerCore module from a low-voltage AC input and draw
significant amounts of current from the PowerCore for external circuits and operate your
PowerCore module at very high ambient temperatures, adding an external 1000 µF capac-
itor to the motherboard can double the lifetime of the AC rectifier filter circuit.
196
through pin 4 and resistors R57 and R58
connected to ground
connector)
PowerCore FLEX