Specifications
Power
Rev 8 Apr.14 Proprietary and Confidential - Contents subject to change 57
Power supply noise
Noise in the power supply can lead to noise in the RF signal.
The power supply ripple limit for the module is no more than 200 mVp-p 1 Hz to
100 kHz. This limit includes voltage ripple due to transmitter burst activity.
Additional decoupling capacitors can be added to the main VCC line to filter noise
into the device.
SED (Smart Error Detection)
The module uses a form of SED to track premature modem resets.
• Module tracks consecutive resets occuring soon after power-on.
• After a sixth consecutive reset, the module waits in boot-and-hold mode for a
firmware download to resolve the power-cycle problem.
Tx power control
The module’s Tx power limit may be controlled using either SAR backoff AT
commands (defined in [2] AirPrime MiniCard MC73xx/MC8805 AT Command
Reference (Doc# 4114486)), or the DPR (Dynamic power control) signal. Use the
GPIOSARENABLE parameter for !CUSTOM to choose the method:
• AT commands:
· !SARSTATED—Set (or report) the default SAR backoff state that the device
uses when it powers up. This setting persists across power cycles and
overrides any PRI setting.
· !SARSTATE—Set (or report) the current SAR backoff state (override the
default state). This change in state is non-persistent across power cycles.
· !SARBACKOFF—Set (or report) the maximum Tx power limit for a specific
band/technology/state combination.
Note: A customization is
available to invert the DPR
logic. (e.g. DPR low = No
SAR backoff)
• Dynamic power control—The module’s firmware monitors DPR (pin 46) and
adjusts the RF Tx power appropriately, as detailed in Ta bl e 5 -8. (This state
change is equivalent to using the !SARSTATE AT command.)
Note: The host can implement an open collector drive for the DPR pin (if a 1.8 V-
compatible drive is not available.)
Table 5-8: Dynamic power control of SAR backoff state
DPR SAR backoff state
High
1
1. DPR is pulled high by default.
No SAR backoff
Low Backoff 1