Analog Devices ADRV9005 Reference Manual page 323

Reference Manual
POWER-SUPPLY RECOMMENDATIONS
CHOOSING THE LDO CONFIGURATION
Before choosing the proper LDO configurations, it is important to understand the power domains used in the system. The LDO configurations
vary depending on the use of RF channels, internal/external LO, or if an external VDDA_1P0 is supplied. Take care when setting the LDO
modes to avoid any potential incorrect voltages getting supplied to the internal blocks.
Table 127 shows the LDO operating modes. Use the enumerators for each mode when setting up the adi_adrv9001_powermanagement_Con-
figure function.
Table 127. LDO Mode for Power-Saving Configurations
Enumerator
ADI_ADRV9001_LDO_POWER_SAVING_MODE_1
ADI_ADRV9001_LDO_POWER_SAVING_MODE_2
ADI_ADRV9001_LDO_POWER_SAVING_MODE_3
ADI_ADRV9001_LDO_POWER_SAVING_MODE_4
ADI_ADRV9001_LDO_POWER_SAVING_MODE_5
LDO mode 1 (normal operation): The LDO is in a normal mode of operation. It is used to generate an on-chip voltage.
►
LDO mode 2 (LDO always off through PCB wiring): An LDO is not required and is permanently powered down through shorting its input pin,
►
and its output pin (if available) to ground on the PCB. Generally, use this mode if the entire power domain is not required. No software control
of the LDO is available.
LDO mode 3 (LDO always off through software): Use this for the various LDOs that do not have a physical output pin. These LDOs cannot
►
be physically tied to GND or bypassed as a result. use it if the LDOs with no output pin must be turned off. See
the LDOs.
LDO mode 5 (LDO in bypass mode): An LDO is not required and is placed into bypass mode through software control. However, the power
►
domain is still required. Apply a high-efficiency power source at the input pin. This mode allows to use higher efficiency power sources to
supply the ADRV9001, as opposed to having the power overhead associated with an LDO.
Table 128 lists each of the 19 LDOs as well as the constraints to explain when to power on/off, or bypass each LDO.
►
analog.com
Figure 305. Power-Saving LDO Configurations
Normal LDO operation.
LDO always off. Input and output of the LDO connected to ground. Used when a power domain is not required.
LDO always off through software.
Not used.
LDO bypassed. Supply an external source at the level expected at the LDO output (1 V, low noise, 2.5%
tolerance).
ADRV9001
Table 128 for the details of
Rev. A | 323 of 377