Datasheet

KSZ9031RNX
DS00002117F-page 65  2016-2017 Microchip Technology Inc.
9.0 REFERENCE CIRCUITS — LED STRAP-IN PINS
The pull-up and pull-down reference circuits for the LED2/PHYAD1 and LED1/PHYAD0 strapping pins are shown in
Figure 9-1 for 3.3V and 2.5V DVDDH.
FIGURE 9-1: REFERENCE CIRCUITS FOR LED STRAPPING PINS
For 1.8V DVDDH, LED indication support requires voltage level shifters between LED[2:1] pins and LED indicator
diodes to ensure the multiplexed PHYAD[1:0] strapping pins are latched in high/low correctly. If LED indicator diodes
are not implemented, the PHYAD[1:0] strapping pins just need 10 k pull-up to 1.8V DVDDH for a value of 1, and 1.0 k
pull-down to ground for a value of 0.
LED PIN
220Ω
10kΩ
PULL-UP
KSZ9031RNX
220Ω
PULL-DOWN
KSZ9031RNX
LED PIN
DVDDH = 3.3V, 2.5V
DVDDH = 3.3V, 2.5V
1k Ω