Bypass Mode; Spi Mode; Tdd Ramp Mode - Analog Devices ADRV9001 User Manual

Preliminary Technical Data
Three Tx attenuation modes are provided as defined by the enum "adi_adrv9001_TxAttenuationControlMode_e":
typedef enum adi_adrv9001_TxAttenuationControlMode
{
ADI_ADRV9001_TX_ATTENUATION_CONTROL_MODE_BYPASS
ADI_ADRV9001_TX_ATTENUATION_CONTROL_MODE_SPI
ADI_ADRV9001_TX_ATTENUATION_CONTROL_MODE_PIN
} adi_adrv9001_TxAttenuationControlMode_e

BYPASS MODE

Bypass mode is selected when the Tx attenuation mode is set as
"ADI_ADRV9001_TX_ATTENUATION_CONTROL_MODE_BYPASS". In this mode, the Tx attenuation functionality is not used
which means 0dB total Tx attenuation.

SPI MODE

SPI mode is selected when the Tx attenuation mode is set as "ADI_ADRV9001_TX_ATTENUATION_CONTROL_MODE_SPI". In this
mode, the user could set the Tx attenuation value via the API command "adi_adrv9001_Tx_Attenuation_Set()".
SPI mode consists of two options, the TDD ramp mode and the constant-step size mode. The TDD ramp mode was designed for power
ramping in TDD systems. Note it is not supported in the current release. The constant-step size mode allows to control an exact constant
gain step size to reach the targeted attenuation level.

TDD RAMP MODE

The TDD ramp mode was designed for use in TDD systems. The user could program an "On power" and "Off power" for the next time
slot. The ramp rate can be controlled via a step size (tdd_ramp_step_size) and wait duration (tdd_ramp_wait_duration) between steps.
The ramp up or down could be initiated through API commands. Note those user interactions are currently not supported but will be
provided in the future. A typical TDD ramp is depicted in Figure 88.
Constant-Step Size Mode
In constant-step size mode, the Tx attenuation controller ramps to the new Tx attenuation value immediately after it is set through API
command. Again the slope can be controlled via a step size (const_step_mode_step_size) and wait duration
(const_step_mode_wait_duration) between steps. A typical output power transient for this mode is shown in Figure 89.
Tx OUTPUT POWER
TDD SLOT
TDD_RAMP_STEP_SIZE
TDD_RAMP_WAIT_DURATION
ATTEN_RAMP_UP
ATTEN_RAMP_DOWN
Figure 88. TDD Ramp Profile
Rev. PrA | Page 93 of 253
= 0,
= 1,
= 3,
FULL-SCALE OUTPUT POWER
DESIRED Tx
ATTENUATION
IN RAMP UP
Tx ON POWER
DESIRED Tx
ATTENUATION
IN RAMP DOWN
Tx OFF POWER
UG-1828