PT0141(06/03)

Ver:0

9

Preliminary Data Sheet

PT8R2401MD 2.4GHz RF Module

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Power Control

In the PT8R2401, there are five different states with different current consumption;

Sleep

,

Idle

,

VCO active

,

TX active

, and

RX active

. Upon reset, the PT8R2401 stays in the

Idle state

to wait for the command through serial programming interface

from the baseband controller. In the Idle state, there is DATACLK from the radio to the baseband controller. In the

Idle mode

,

all RF circuits are shut down to reduce the static current consumption. Only the reference clock oscillator and DATACLK

pump to the baseband is active. After HOP set command through the serial programming, the VCO will operate to lock the

programmed channel frequency. Owing to the signal such as RXACTIVE or TXACTIVE, the PT8R2401 will enter into the

active state such as

TX active state

and

RX active state

. In those state, all RF circuits and GFSK modem will operate and

result in the maximum current consumption. In the unidirectional mode, the falling signal of RXACTIVE or TXACTIVE will

make the PT8R2401 into

Idle state

automatically. In the bidirectional mode, the explicit command to stop receive or

transmission through serial programming will make the PT8R2401 into

Idle state

. The PT8R2401 enters into

Sleep state

by

power down command through serial programming.

Sleep state

is the least power consumption among other states and all

clocks include reference oscillator will stop the operation as well as the power down of all RF circuits. In

Sleep state

, only the

serial programming interface logic can operate which uses clock from external device. However, the value of all registers will

sustain until the wake up from

Sleep state

. Following figure shows the state transition in terms of power control.

Figure 8. State transition diagram for power control

Idle state

(I

Idle

)

VCO active state

(I

VCO

)

RX active state

(I

RX

)

Sleep state

(I

Sleep

)

TX active state

(I

TX

)

HOP command

Transmit command

Receive command

Power-Down command

Power-Up command

RXACTIVE off

TXACTIVE off