ADF4158+BGT24MTR11 Frequency lock

Hi flyman 

When I checked your register settings, I saw that you set the R_Divider value to 0. This is an undefined state. Can you update the R_Divider value to 1?  

Besides, I strongly recommend using ADISimPLL to model your VCO and simulate your setup. 

Using ADIsimPLL to Simulate Frequency Ramps on the ADF4158 | Analog Devices

ADIsimPLL: Creating a custom voltage-controlled oscillator (VCO) | Analog Devices

Thanks,

Emrecan

The configuration is as follows:
unsigned char R0[] = { 0x00, 0x24, 0xB8, 0x00}; // 23.50001 GHz
unsigned char R1[] = {0x02, 0x26, 0x00, 0x01}; // 23.50001 GHz
unsigned char R2[] = { 0x02, 0x20, 0xFD, 0x02};
unsigned char R3[] = { 0x00, 0x00, 0x00, 0x43};
unsigned char R4[] = { 0x00, 0x18, 0xF4, 0x04};
unsigned char R5_load1[] = { 0x00, 0x49, 0x40, 0x05};
unsigned char R5_load2[] = { 0x00, 0x80, 0x00, 0x7D};
unsigned char R6_load1[] = { 0x00, 0x00, 0x00, 0x56};
unsigned char R6_load2[] = { 0x00, 0x80, 0x00, 0x06};
unsigned char R7[] = { 0x00, 0x02, 0xFD, 0x07};

The modulation voltage has not changed

Hi,

Can you try to change the register 2 value to 0x210FD02?

Thanks,

Emrecan

Hi,

Can you try to change the register 2 value to 0x210FD02?

Thanks,

Emrecan

The modulation voltage has not changed

 REF:10MHZ WAVEFORM

Hi flyman,

I investigated BGT24MTR11 and found that this chip has two different Vtune structures. Did you set the COARSE Vtune value to achieve 23.5 GHz? Can you debug the system by using the following method?

- First set Coarse Vtune value to achieve 23.5GHz

-Set ADF4158  Charge pump Tri-state mode to enabled.

- Apply 2V to Fine Vtune of BGT24MTR11

- Observe the frequency. If the frequency is close the 23.5GHz then we will further investigate the PLL. 

By the way, according to the BGT24MTR11 datasheet, 23.5GHz is not supported.

Thanks,
Emrecan