Re: [ARTIQ] clock recovery on Metlino and Kasli
Hi, my question was whether one can get rid of all those 6 parts and replace them with a Si5324 circuit (instead of #1 and supporting parts) and internal FPGA PLL(s) (instead of #2 and supporting parts). Why did you design it that way - what do all those additional parts bring exactly? Sébastien On Thursday, June 30, 2016 12:06 AM, Grzegorz Kasprowicz wrote: Hi The idea is to use SPEC board design: http://www.ohwr.org/projects/spec/wiki It's well debugged. I designed it a few years ago and it's already 4-th revision. The WR components are: 1. 25MHz VCXO VM53S3-25.000-2.5/-30+75 + CDCM61004RHBT PLL chip. The two can be replaced by 125MHz VCXO. 2. 20MHz helper VCXO for DDMTD : LF VCXO026156 3. 2x DAC AD5662BRMZ-1 4. 3V LDO : LP5951MF-3.0/NOPB 5. 2.5V reference: LM336M-2.5/NOPB 6. some LRC passives Greg On 29 June 2016 at 15:56, j arl mailto:joe.britton@gmail.com>> wrote: As the topic shifted from backplane logic, I've moved to this conversation to a new thread. On Tuesday, June 28, 2016 04:02 PM, Grzegorz Kasprowicz wrote: > For synchronisation over fibre we can use existing White Rabbit core. > The card requires only 2 VCXO oscillators and FPGA logic. The WR core > consumes 50% of small Spartan 45T. It ensures 1ns timing accuracy. >We probably won't use White Rabbit as-is, but the basic principle will >be the same. It can be a good idea to include those VCXOs on boards that >may be synchronized over fiber (Kasli/Metlino), though can't we use >instead a Si5324 for jitter cleanup and FPGA PLLs for DDMTD? Heads up that the clock synchronization for Metlino resides on Metlino_clk (Tongue 2) not Metlino_motherboard (Tongue 3-4). So headers need to provide whatever io is required. Greg already has a layout for a Metlino_clk board that has White Rabbit components on it. Greg, do you have a short list of components required for WhiteRabbit-type clock recovery? -Joe ___ ARTIQ mailing list https://ssl.serverraum.org/lists/listinfo/artiq
[ARTIQ] clock recovery on Metlino and Kasli
As the topic shifted from backplane logic, I've moved to this conversation to a new thread. On Tuesday, June 28, 2016 04:02 PM, Grzegorz Kasprowicz wrote: > For synchronisation over fibre we can use existing White Rabbit core. > The card requires only 2 VCXO oscillators and FPGA logic. The WR core > consumes 50% of small Spartan 45T. It ensures 1ns timing accuracy. >We probably won't use White Rabbit as-is, but the basic principle will >be the same. It can be a good idea to include those VCXOs on boards that >may be synchronized over fiber (Kasli/Metlino), though can't we use >instead a Si5324 for jitter cleanup and FPGA PLLs for DDMTD? Heads up that the clock synchronization for Metlino resides on Metlino_clk (Tongue 2) not Metlino_motherboard (Tongue 3-4). So headers need to provide whatever io is required. Greg already has a layout for a Metlino_clk board that has White Rabbit components on it. Greg, do you have a short list of components required for WhiteRabbit-type clock recovery? -Joe ___ ARTIQ mailing list https://ssl.serverraum.org/lists/listinfo/artiq
Re: [ARTIQ] uTCA backplane driver choices
we can use Si instead of CDCM61004RHBT Greg On 29 June 2016 at 04:56, Sébastien Bourdeauducq wrote: > On Tuesday, June 28, 2016 04:02 PM, Grzegorz Kasprowicz wrote: > >> For synchronisation over fibre we can use existing White Rabbit core. >> The card requires only 2 VCXO oscillators and FPGA logic. The WR core >> consumes 50% of small Spartan 45T. It ensures 1ns timing accuracy. >> > > We probably won't use White Rabbit as-is, but the basic principle will be > the same. It can be a good idea to include those VCXOs on boards that may > be synchronized over fiber (Kasli/Metlino), though can't we use instead a > Si5324 for jitter cleanup and FPGA PLLs for DDMTD? > > Sébastien > ___ ARTIQ mailing list https://ssl.serverraum.org/lists/listinfo/artiq
Re: [ARTIQ] clock recovery on Metlino and Kasli
Hi The idea is to use SPEC board design: http://www.ohwr.org/projects/spec/wiki It's well debugged. I designed it a few years ago and it's already 4-th revision. The WR components are: 1. 25MHz VCXO VM53S3-25.000-2.5/-30+75 + CDCM61004RHBT PLL chip. The two can be replaced by 125MHz VCXO. 2. 20MHz helper VCXO for DDMTD : LF VCXO026156 3. 2x DAC AD5662BRMZ-1 4. 3V LDO : LP5951MF-3.0/NOPB 5. 2.5V reference: LM336M-2.5/NOPB 6. some LRC passives Greg On 29 June 2016 at 15:56, j arl wrote: > As the topic shifted from backplane logic, I've moved to this > conversation to a new thread. > > On Tuesday, June 28, 2016 04:02 PM, Grzegorz Kasprowicz wrote: > > For synchronisation over fibre we can use existing White Rabbit core. > > The card requires only 2 VCXO oscillators and FPGA logic. The WR core > > consumes 50% of small Spartan 45T. It ensures 1ns timing accuracy. > > >We probably won't use White Rabbit as-is, but the basic principle will > >be the same. It can be a good idea to include those VCXOs on boards that > >may be synchronized over fiber (Kasli/Metlino), though can't we use > >instead a Si5324 for jitter cleanup and FPGA PLLs for DDMTD? > > Heads up that the clock synchronization for Metlino resides on > Metlino_clk (Tongue 2) not Metlino_motherboard (Tongue 3-4). So > headers need to provide whatever io is required. Greg already has a > layout for a Metlino_clk board that has White Rabbit components on it. > > Greg, do you have a short list of components required for > WhiteRabbit-type clock recovery? -Joe > ___ ARTIQ mailing list https://ssl.serverraum.org/lists/listinfo/artiq