ADM7008
Function Description
3.5.2 Transmit Power Saving
In ADM7008, enabling TX Power Saving Feature could save transmit power before any
link partner trying to link up. Two transmit power saving methods are applied to
ADM7008 by register 17.5 configuration. When setting register 17.5 to “0”, the transmit-
driver will lower the driving current all the time to save power before the receiver detects
signals coming in. When setting to “1”, ADM7008 transmit Low-power Link Pulse
(LLP) to the cable. The waveform of LLP is the same as NLP and FLP, the difference is
the period of LLP is around 100ms. Besides the longer period, ADM7008 also lower the
transmit-driving current between sending a pulse and a pulse. The TX Power Saving
Feature is activated by setting ADM7008 of N-way or 10M capabilities. See Figure 3-26
for reference.
PWR_RST ||
Software_RST
IDLE
DISALL = 1
ENCARDET = 1
NO
SD = 1
YES
Carrier ?
ENANEN = 1
YES
Auto Negotiation
Process
Figure 3-25 Medium Detect Power Management Flow Chart
Another way to reduce instant power is to separate the LED display period. All 24 LEDs
will be divided into 24 time frame and each time frame occupies 1 us. One and only one
LED will be driven at each time frame to reduce instant current consumed from LED.
ADMtek Inc.
3-27
ETC [ ETC ]
