ADAR2001ACCZ datasheet(19/39 Pages) AD

19 / 39 page

Data Sheet

ADAR2001

Rev. 0 | Page 19 of 39

SINGLE FREQUENCY CHANNEL SWEEP

Figure 30 shows how the transmitter state machine can be used

to cycle through the four PAs on a single ADAR2001 while at a

fixed frequency. In this example, the defined state machine

depth, TX_STATES (Register 0x017, Bits[6:0]), is 5 because

there are 6 states inside the loop, and TX_STATES is 0 indexed.

As shown in Figure 30,

•

Transmit State 0 = sleep (outside the loop)

•

Transmit State 1 = Channel 1 PA ready

•

Transmit State 2 = transmit on Channel 1, Channel 2 PA

ready

•

Transmit State 3 = transmit on Channel 2, Channel 3 PA

ready

•

Transmit State 4 = transmit on Channel 3, Channel 4 PA

ready

•

Transmit State 5 = transmit on Channel 4

The initial state is the sleep state, where power consumption is

at a minimum. This state is reached by pulsing the TxRST pin.

A pulse on TxADV then advances the state machine to the first

state inside the loop, which is defined as a ready state, where

Channel 1 is partially powered but not active. The splitters

feeding Channel 1 are active to speed up the switching speed of

the next state. An additional pulse on TxADV then makes this

subcircuit path fully active. Continuing to make use of the

ready mode for the upcoming state throughout the sweep, the

PA switching and settling time can be minimized for all states.

After the appropriate number of pulses are applied to TxADV

(6, in this case), the state machine automatically returns to the

first state in the loop (ready).

MULT: ALL SLEEP

BPF: N/A

PA: ALL SLEEP

SLEEP

MULT_STATE_0

TX_STATE_0

MULT: LOW RDY

BPF: N/A

PA: CH. 1 RDY

CHANNEL 1

READY

MULT_STATE_1

TX_STATE_1

MULT: LOW ACT

BPF: LOW

PA: CH. 1 ACT

CHANNEL 1

10GHz TO 12GHz

MULT_STATE_2

TX_STATE_2

MULT: LOW ACT

BPF: LOW

PA: CH. 2 ACT

CHANNEL 2

10GHz TO 12GHz

MULT_STATE_2

TX_STATE_3

MULT: LOW ACT

BPF: LOW

PA: CH. 3 ACT

CHANNEL 3

10GHz TO 12GHz

MULT_STATE_2

TX_STATE_4

MULT: LOW ACT

BPF: LOW

PA: CH. 4 ACT

CHANNEL 4

10GHz TO 12GHz

MULT_STATE_2

TX_STATE_5

MULTIPLIER

RESET

TRANSMITTER

RESET

MULTIPLIER

ADVANCE

TRANSMITTER

ADVANCE

MULTIPLIER

ADVANCE

TRANSMITTER

ADVANCE

TRANSMITTER

ADVANCE

TRANSMITTER

ADVANCE

MULTIPLIER

ADVANCE

TRANSMITTER

ADVANCE

TRANSMITTER

ADVANCE

Figure 30. State Machine Loop Example for a Channel Sweep with a Fixed Frequency

ADAR2001ACCZ Folha de dados(PDF) 19 Page - Analog Devices

ADAR2001ACCZ Folha de dados(HTML) 19 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

Folha de dados Download

Ligação URL