lan8720 Standard Microsystems Corp., lan8720 Datasheet - Page 33

• Manufacturer Part Number: lan8720
• Description: Small Footprint Rmii 10/100 Ethernet Transceiver With Hp Auto-mdix Support
• Manufacturer: Standard Microsystems Corp.

Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
SMSC LAN8720/LAN8720i
4.11
LED output = active low
10K
REGOFF = 1 (Regulator OFF)
The REGOFF configuration pin is shared with the LED1 pin. The LED1 output will automatically
change polarity based on the presence of an external pull-up resistor. If the LED pin is pulled high to
VDD2A by an external pull-up resistor to select a logical high for REGOFF, then the LED output will
be active low. If the LED pin is pulled low by the internal pull-down resistor to select a logical low for
REGOFF, the LED output will then be an active high output.
To set REGOFF without LEDs, pull-up the pin with an external resistor to VDDIO to disable the
regulator. See
REGOFF and LED Polarity Selection
VDD2A
nINTSEL = 1
LED output = active low
~270 ohms
VDD2A
~270 ohms
LED2/nINTSEL
Figure
LED1/REGOFF
Figure 4.9 REGOFF Configuration on LED1
4.9.
Figure 4.8 nINTSEL Strapping on LED2
DATASHEET
33
LED output = active high
LED output = active high
10K
nINTSEL = 0
REGOFF = 0
~270 ohms
~270 ohms
LED2/nINTSEL
LED1/REGOFF
Revision 1.0 (04-15-09)