TX Power Mode Switching
The transceiver is in default High TX Power Mode
upon powered on. User needs to apply the following
programming sequence to both SD and TXD inputs
to switch the module to Low TX Power Mode. Both
settings of High TX Power and Low TX Power Mode
can be achieved as follows:
V
V
V
IH
IH
IL
SD/MODE
50%
SD/MODE
50%
V
IL
t
t
H
t
t
S
S
H
V
V
IH
50%
50%
50%
50%
TXD
TXD
V
IL
IL
Figure 3. High power mode selection timing diagram.
Figure 4. Low power mode selection timing diagram.
1. Set SD/Mode input to logic High.
1. Set SD/Mode input to logic High.
2. TXD input should remain at logic Low.
2. After SD/Mode input remains High at > 25 ns, set
TXD input to logic High, wait t ≥ 25 ns (from 50%
of TXD rising edge until 50% of SD falling edge).
s
3. After waiting for t ≥ 25 ns, set SD/Mode to logic
s
Low. The High to Low negative edge transition will
determine the TX Power Mode.
3. Then set SD/Mode to logic Low. The High to Low
negative edge transition will determine the TX
Power Mode.
4. Ensure that TXD input remains low for t ≥ 100 ns.
H
The transmitter is now in High mode.
4. After waiting for t ≥ 100 ns, set the TXD input to
H
5. SD input pulse width for mode selection should be
> 50 ns.
logic Low.
5. SD input pulse width for mode selection should be
> 50 ns.
3
LITEON [ LITE-ON TECHNOLOGY CORPORATION ]
