Measuring Gains

The goal of this section is to find four gain values, TRSW_RX, the LNA lod, the LNA value and the PGA Value. The maximum RX Gain is required. If this is a negative value, use 0 instead.

After using the tables below to check the values:

  1. If the LNA lod value is 0

    1. AND Radio Register 0x7A with 0xFFF7

  2. Otherwise
    1. OR Radio Register 0x7A with 0x8

Loopback Gain Enabled

  1. If using the TRSW_RX value is desired
    1. Take the TRSW_RX Gain (in hdB, from Loopback Gain measurement) and divide by 2

    2. If the maxmimum Gain value is greater or equal to the result
      1. Subtract the result from the maximum Gain value, this value will be referred to as the TRSW_RX Gain
      2. The TRSW_RX value is 0x20

  2. Otherwise
    1. The TRSW_RX Gain is the maximum Gain value
    2. The TRSW_RX value is 0

  3. If the TRSW_RX Gain is < 9

    1. The LNA lod value is 0

  4. Otherwise
    1. The LNA lod value is 1

    2. Subtract 0x8 from the TRSW_RX Gain value
  5. Clamp the TRSW_RX Gain value between [0, 0x2D]
  6. Divide the TRSW_RX Gain value by 3 to find the PGA Value

  7. If the PGA Value is 5 or greater

    1. Subtract 5 from the PGA Value

    2. The LNA Value is 2

  8. Otherwise
    1. The LNA Value is 0

Loopback Gain Disabled



LNA Value


The other values depend on the maximum RX gain as shown below:

Maximum RX Gain

LNA lod

PGA Value

>= 0x14



0x14 > x >= 0x12



0x12 > x >= 0xF



0xF > x



Exported/Archived from the wiki to HTML on 2016-10-27