Micrel, Inc.
KSZ9021RL/RN
Reset Timing
The recommended KSZ9021RL/RN power-up reset timing is summarized in the following figure and table.
Supply
Voltage
tsr
RESET_N
Figure 8. Reset Timing
Parameter
Description
Min
Max
Units
tsr
Stable supply voltage to reset high
10
ms
Table 13. Reset Timing Parameters
After the de-assertion of reset, it is recommended to wait a minimum of 100µs before starting programming on the MIIM
(MDC/MDIO) Interface.
Reset Circuit
The following reset circuit is recommended for powering up the KSZ9021RL/RN if reset is triggered by the power supply.
3.3V
D1: 1N4148
D1
R 10K
KSZ9021RL/RN
RESET_N
C 10uF
Figure 9. Recommended Reset Circuit
M9999-101309-1.1
October 2009
51
MICREL [ MICREL SEMICONDUCTOR ]
