diff --git a/firmware/common/max2871.c b/firmware/common/max2871.c
new file mode 100644
index 00000000..387a2e25
--- /dev/null
+++ b/firmware/common/max2871.c
@@ -0,0 +1,115 @@
+/*
+ * - The input is fixed to 50 MHz
+ * f_REF = 50 MHz
+ *
+ * - The VCO must operate between 3 GHz and 6 GHz
+ * f_VCO range: 3 GHz - 6 GHz
+ *
+ * Phase Detector Clock:
+ *      - We configure the phase detector to not change the
+ *        input signal
+ *      f_PFD = f_REF x [(1 + DBR)/(R x (1 + RDIV2))]
+ *      R = 1
+ *      DBR = 0
+ *      RDIV2 = 0
+ *
+ *      => f_PFD = 50 MHz
+ *
+ *
+ * f_RFOUT < 3 GHz:
+ *  - To go to < 3 GHz, f_VCO has to be divided.
+ *  f_RFOUT = f_VCO / DIVA
+ *
+ *  - We just divide by 2 for now
+ *  DIVA = 2
+ *  => f_RFOUT = f_VCO / 2
+ *  
+ *  - Relationship between f_PFD (fixed) and f_VCO (variable)
+ *  N + (F/M) = f_VCO/ f_PFD
+ *
+ *  - Insert relationship between f_RFOUT and f_VCO:
+ *  N + (F/M) = (f_RFOUT * 2) / f_PFD
+ *  f_RFOUT = (N + F/M) * f_PFD / 2
+ *
+ *  - Limits for N, M and F from the datasheet:
+ *  19 <= N <= 4091
+ *  2  <= M <= 4095
+ *  F < M
+ *
+ *  - Plug in constants:
+ *  f_RFOUT = (N + F/M) / 2 * 50 MHz
+ *
+ *  - Given the range of N, we can go to:
+ *  f_RFOUT range: 475 MHz - 3 GHz
+ *
+ *  - N steps in 25 MHz increments:
+ *  N = floor(f_RFOUT / 50 MHz * 2)
+ *      => N = (f_RFOUT * 2) / 50 MHz (uses integer math)
+ *
+ *  - Calculate the error:
+ *  f_int_ERROR = f_RFOUT - (N * 50 MHz) / 2
+ *  f_int_ERROR range: 0 MHz - 24 MHz
+ *
+ *  - Use the fraction to get to the correct frequency:
+ *  (F/M) / 2 * 50 MHz = f_int_ERROR
+ *
+ *  - Fix M:
+ *  M = 25
+ * 
+ *  - Calculate F:
+ *  (F/25) / 2 * 50 MHz = f_int_ERROR
+ *  F = f_int_ERROR / 1 MHz
+ *
+ *  - Calculate the new error:
+ *
+ *  f_ERROR = f_RFOUT - (N + F/M) / 2 * 50 MHz
+ *  f_ERROR range: 0 MHz - 1 MHz
+ *
+ *
+ * f_RFOUT > 3 GHz:
+ *  - Do not divide the VCO output
+ *  DIVA = 1
+ *  => f_RFOUT = f_VCO
+ *
+ *  - Relationship between f_PFD (fixed) and f_VCO (variable)
+ *  N + (F/M) = f_VCO/ f_PFD
+ *
+ *  - Insert relationship between f_RFOUT and f_VCO:
+ *  N + (F/M) = f_RFOUT / f_PFD
+ *  f_RFOUT = (N + F/M) * f_PFD
+ *
+ *  - Limits for N, M and F from the datasheet:
+ *  19 <= N <= 4091
+ *  2  <= M <= 4095
+ *  F < M
+ *
+ *  - Plug in constants:
+ *  f_RFOUT = (N + F/M) * 50 MHz
+ *
+ *  - Given the range of N and the VCO limits, we can go to:
+ *  f_RFOUT range: 3000 MHz - 6000 MHz
+ *
+ *  - N steps in 50 MHz increments:
+ *  N = floor(f_RFOUT / 50 MHz)
+ *      => N = f_RFOUT / 50 MHz (uses integer math)
+ *
+ *  - Calculate the error:
+ *  f_int_ERROR = f_RFOUT - N * 50 MHz
+ *  f_int_ERROR range: 0 MHz - 49 MHz
+ *
+ *  - Use the fraction to get to the correct frequency:
+ *  (F/M) * 50 MHz = f_int_ERROR
+ *
+ *  - Fix M:
+ *  M = 50
+ * 
+ *  - Calculate F:
+ *  (F/50) * 50 MHz = f_int_ERROR
+ *  F = f_int_ERROR / 1 MHz
+ *
+ *  - Calculate the new error:
+ *
+ *  f_ERROR = f_RFOUT - (N + F/M) * 50 MHz
+ *  f_ERROR range: 0 MHz - 1 MHz
+ *
+ */