LAN8720AI-CP-TR SMSC, LAN8720AI-CP-TR Datasheet - Page 38

• Manufacturer Part Number: LAN8720AI-CP-TR
• Description: Ethernet ICs 10/100 Ethernet XCVR w/HP AutoMDIXSupport
• Manufacturer: SMSC

Specifications of LAN8720AI-CP-TR

• Product: Ethernet Transceivers
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Revision 1.2 (11-10-10)
3.8.2
3.8.3
3.8.3.1
3.8.3.2
pin is pulled low by an external pull-down resistor to select a logical low for nINTSEL, the LED2 output
will then be an active high output.
Note: Refer to
Variable Voltage I/O
The device’s digital I/O pins are variable voltage, allowing them to take advantage of low power savings
from shrinking technologies. These pins can operate from a low I/O voltage of +1.62V up to +3.6V.
The applied I/O voltage must maintain its value with a tolerance of ± 10%. Varying the voltage up or
down after the transceiver has completed power-on reset can cause errors in the transceiver operation.
Refer to
Note: Input signals must not be driven high before power is applied to the device.
Power-Down Modes
There are two device power-down modes: General Power-Down Mode and Energy Detect Power-
Down Mode. These modes are described in the following subsections.
General Power-Down
This power-down mode is controlled via the
mode, the entire transceiver (except the management interface) is powered-down and remains in this
mode as long as the
powers up and is automatically reset.
Energy Detect Power-Down
This power-down mode is activated by setting the
Register. In this mode, when no energy is present on the line the transceiver is powered down (except
for the management interface, the SQUELCH circuit, and the ENERGYON logic). The ENERGYON
logic is used to detect the presence of valid energy from 100BASE-TX, 10BASE-T, or Auto-negotiation
signals.
In this mode, when the
powered-down and nothing is transmitted. When energy is received via link pulses or packets, the
ENERGYON
LED output = Active Low
VDD2A
information on the nINTSEL configuration strap.
nINTSEL = 1
~270 ohms
Chapter 5, "Operational Characteristics," on page 63
bit goes high and the transceiver powers-up. The device automatically resets into the
LED2/nINTSEL
Section 3.7.4, "nINTSEL: nINT/REFCLKO Configuration," on page 33
Figure 3.11 LED2/nINTSEL Polarity Configuration
Power Down
ENERGYON
Figure 3.11
DATASHEET
bit is “1”. When the
bit of the
38
details the LED2 polarity for each nINTSEL configuration.
LED output = Active High
Power Down
Mode Control/Status Register
Small Footprint RMII 10/100 Ethernet Transceiver with HP Auto-MDIX Support
10K
nINTSEL = 0
EDPWRDOWN
Power Down
bit of the
~270 ohms
for additional information.
LED2/nINTSEL
bit of the
Basic Control
bit is cleared, the transceiver
SMSC LAN8720A/LAN8720Ai
is low, the transceiver is
Mode Control/Status
Register. In this
for additional
Datasheet