
January 2005
47
KS8999
Micrel
Reference Circuits
See
“I/O Description” section for pull-up/pull-down and float information.
KS8999
LED pin
VDD-IO
Reference circuits for unmanaged programming through LED ports
Note: For brighter LED operation use VDD-IO = 3.3V
KS8999
LED pin
VDD-IO
Pull Down
Pull -up
KS8999
LED pin
VDD-IO
Float
Pull-down
220
220
220
1k
10k
Figure 19. Unmanaged Programming Circuit
Reset Reference Circuit
Micrel recommendeds the following discrete reset circuit as shown in Figure 20 when powering up the KS8999 device. For
the application where the reset circuit signal comes from another device (e.g., CPU, FPGA, etc), we recommend the reset circuit
as shown in Figure 21.
VCC
R
10k
D2
C
10F
D1
CPU/FPGA
RST_OUT_n
KS8999
RST
D1, D2: 1N4148
Figure 20. Recommended Reset Circuit.