HARDWARE PREPARATION AND INSTALLATION
M68HC11EVBU/D
2-15
2.4.1
Diode Jumpers (D1-D4)
Diode jumpers D1-D4 (shown below) are provided on the EVBU for the real-time clock battery
backup operations. The diode jumpers (D1), (D2), and (D3) consist of feed-thru holes with cut
traces on the PCB solder side. Diode jumper D4 feed-thru holes do not include a cut trace.
D4
D1
D2
D3
1
2
1
1
2
2
1
2
1
2
1
2
If the MC68HC68T1 real-time clock battery backup feature is required, you must cut the D1-D3
feed-thru hole cut traces on the PCB solder side, and install the following user-supplied
components on the PCB component side as follows:
D1
1N4001 diode
D2
1N4148 diode
D3
1N4148 diode
D4
1N4148 diode, jumper wire, or resistor (application dependent)
A user-su3.0 Vdc @ 25 µA battery is connected to the EVBU battery connector P3
(feed-thru holes desi and -) for battery backup purposes as shown below.
-
+
P3
Summary of Contents for M68HC11EVBD
Page 4: ......
Page 92: ...HARDWARE DESCRIPTION 5 4 M68HC11EVBU D ...
Page 101: ...SUPPORT INFORMATION M68HC11EVBU D 6 9 Figure 6 2 EVBU Schematic Diagram Sheet 1 of 3 ...
Page 102: ...SUPPORT INFORMATION 6 10 M68HC11EVBU D ...
Page 103: ...SUPPORT INFORMATION M68HC11EVBU D 6 11 Figure 6 2 EVBU Schematic Diagram Sheet 2 of 3 ...
Page 104: ...SUPPORT INFORMATION 6 12 M68HC11EVBU D ...
Page 105: ...SUPPORT INFORMATION M68HC11EVBU D 6 13 Figure 6 2 EVBU Schematic Diagram Sheet 3 of 3 ...