User`s manual

User’s Manual 35
C.4 Power Supplies
Power is supplied to the RabbitLink board from an external source either through jack J4
or through screw terminal connector J5. The connection through jack J4 is protected
against reverse polarity by a Schottky diode at D1 as shown in Figure C-4.
Figure C-4. RabbitLink Power Supply Schematic
The power supply connection through jack J4 is handy for the AC adapter included with
the RabbitLink tool kit for desktop demonstration and development. The power supply
connection through screw terminal connector J5 enables you to connect the RabbitLink
directly to a power supply in the production system.
Capacitor C8 provides noise and ripple stabilization protection for the voltage regulator,
and allows the external power supply to be located some distance away from the Rab-
bitLink. A switch ing power regulator is used. The +RAW input voltage may range from 9 V
to 40 V.
C.5 Reset Generator
The RabbitLink uses a reset generator, U14, to reset the Rabbit 2000 microprocessor when
the voltage drops below the voltage necessary for reliable operation. The reset occurs
between 4.50 V and 4.75 V, typically 4.63 V.
47 µF
330 µF
LM2575
U16
Vcc
L1
C1
C8
330 µH
D2
1N5819
14
15
8
1
12
7
17
18
10
2
3
4
1
SWITCHING POWER REGULATOR
POWER
IN
J4
1
2
D1
+RAW
3
J5
6
1
J5