Using the AT85DVK-07 Board
AT85DVK-07 Development Board User Guide
2-7
4391B–MP3–07/07
2.2
Power
Management
Unit
The Power Management unit allows three different power supply sources along with a
set of solder strap allowing configuration of “Very Low Voltage 1.8V application” or “Low
Voltage 3V application”. Figure 2-3 shows the power management unit implementation.
Jumpers J36, J37, J38, J39 must always be in place for proper operation and are imple-
mented for current measurement purpose only (see Section 2.14).
Figure 2-3.
Power Management Unit Implementation
2.2.1
Battery Power
Supply
The AT85DVK-07 Board allows direct plug-in of a single AAA battery element or a AA
battery as an option.
Table 2-1.
Battery Power Supply Range
2.2.2
External Power
Supply Connection
In order to operate without battery during firmware development process the AT85DVK-
07 Board provides an external power supply input through connector J20.
Notes:
1. Remove any plugged battery from the socket before applying the external voltage.
2. The external power supply input is
not protected
against polarization inversion.
Table 2-2.
External Power Supply Connector Pinout (J20)
Table 2-3.
External Power Supply Range
Figure 2-4.
External Power Supply Cable
2.2.3
USB V
BUS
Power
Supply
The AT85C51SND3Bx provides direct connection of USB V
BUS
power supply. When
V
BUS
is present, the on-chip or on-board DC-DC is disabled to avoid battery power
consumption.
Table 2-4.
USB V
BUS
Power Supply Range
J20
J
3
6
L
E
D
J
3
8
J
3
9
J37
J22
J19
Power supply source
Min.
Max.
Unit
Battery Power Supply
0.9
1.5
V
Pin Number
Pin Name
Pin Description
1
VBAT
+ 1.5V supply voltage
2
VSS
0V supply reference
Power supply source
Min.
Max.
Unit
External Power Supply
0.9
3.0
V
+
-
+
-
Power supply source
Min.
Max.
Unit
V
BUS
Power Supply
4.4
5.5
V
