Analog Devices ADRV9005 Reference Manual page 89

Reference Manual
MICROPROCESSOR AND SYSTEM CONTROL
Similar to transmit timing parameters, as shown in
parameter (ADRV9001 provides to the user), user parameter (user provides to the ADRV9001), and helper parameters (determined by the
user, which do not have to provide to the ADRV9001 but can be used to derive other required timing parameters).
All the parameters used in Figure 70
No hardware, or software restrictions prevent from setting out of bound values. The following sections specify the maximum programmable
parameter value.
Table 35. Receive Timing Parameters Description
Delay
enableSetupDelay
(t )
RxEnaSetup
propagationDelay(t )
RxPD
enableRiseToAnalogOnDelay
(t )
RxEnaRise2AnaOn
enableRiseToOnDelay
(t )
RxEnaRise2On
enableGuardDelay
(t )
RxGT
enableFallToOffDelay
(t )
RxEnaFall2Off
enableHoldDelay
(t )
RxEnaHold
Design Strategy for Receive Timing Parameters
As described, the ADRV9001 provides the enableSetupDelay, which is the time required to power up the receiver front end. By knowing this,
set the RX_ENABLE pin high as at least enableRiseToOnDelay in advance, as shown in
savings or frequency hopping, set enableRiseToAnalogOnDelay always to 0, so that analog power-up begins immediately after the receive
enable's rising edge (note that
equal to 0.) Set the parameter enableRiseToOnDelay also to 0. In this case, the LNA is powered up as soon as analog power up completes. For
a more deterministic delay between the RX_ENABLE rising edge and LNA power up time, set enableRiseToOnDelay to a value greater than or
equal to:
enableRiseToAnalogOnDelay + enableSetupDelay.
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Figure 68, receive timing parameters can be categorized into three types: ADRV9001
are explained further in
Provided By Bounds
ADRV9001
Min: N/A
Parameter
Max: N/A
Helper Parameter
Min: N/A
Max: N/A
User Parameter
Min: 0
Max: duration of pow-
er up tasks in power
savings or frequency
hopping modes.
User Parameter
Min: t
RxEnaRise2AnaOn
Typ: t
RxEnaRise2AnaOn
+ t
RxEnaSetup
Max: None. Must be
optimized to be mini-
mal.
User Parameter Min: N/A
Max: N/A
User Parameter
Min: 0
Max: None. Must be
optimized to be mini-
mal.
User Parameter
Min: t
RxEnaFall2Off
Max: None. Must be
optimized to be mini-
mal.
(Recommended Max:
t + t
RxEnaFall2Off
Figure 70 describes the receive timing parameters in a general case with enableRiseToAnalogOnDelay not
Table 35. All bounds specified in
Comments
No PLL tuning at frame boundary: 8 μs (analog power-up time)
PLL tuning at frame boundary: 758 μs (analog power-up time + PLL tuning time)
(The PLL tuning time 750 μs refers to when internal LO is used and it represents the
worst case. When external LO is used, calculate and use own PLL tuning time.)
Meaure this parameter. It is profile and board layout dependent. It does not have to
provide to the ADRV9001. However, use it to derive values for other parameters required
by the ADRV9001.
Only set to non-zero values if using power savings or frequency hopping. See the
following sections to determine how to choose a non-zero value.
If set to t , the actual delay is t
RxEnaRise2AnaOn
Reserved
Ideally, RX_ENABLE falling edge arrives when the last valid data is received over the
air. By setting this value greater than 0, the ADRV9001 can continue receiving guard
symbols, while signaling to certain algorithms or other systems that the valid data for the
frame is already received.
The interface is disabled only after analog power down is completed.
At minimum bound: Some of the data received at the antenna may not make it over the
interface.
At maximum bound: Digital datapath and receive SSI remain enabled until last received
data is propagated to the interface.
.)
RxPD
Figure
ADRV9001
Table 35 are suggestions for optimal operation.
+ t
RxEnaRise2AnaOn RxEnaSetup
70. In regular TDD mode, i.e., no power
.
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