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**BabyWR** is being developed as a cost effective and small pluggable WR node. BabyWR has a [M.2 form-factor](https://en.wikipedia.org/wiki/M.2). BabyWR is designed for low phase noise (10 MHz; < -100 dBc/Hz @ 10 Hz) timing generation. For applications that demand ultimate low phase noise, an external high precision oscillator can be disciplined and used as reference clock.
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The standard M.2 Type 2260-D6-M form factor module provides 10 MHz and 1 PPS signals that are generated by the [White Rabbit PTP Core](https://ohwr.org/project/wr-cores/wikis/Wrpc-core).
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FPGA phase noise is the limiting factor. Phase noise can be further improved when re-clocking the 10 MHz and 1 PPS signals using the clean reference oscillator as is proven for the M.2 Type 2280-D6-M form factor module. However, for re-clocking "lock sweep" needs to be implemented in order to find the have proper phase alignment. Lock sweep increases the time it takes to establish a link and lock sweep is not yet officially implemented; two reasons to use standard M.2 Type 2260-D6-M for the time being.
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FPGA phase noise is the limiting factor. Phase noise can be further improved when re-clocking the 10 MHz and 1 PPS signals using the clean reference oscillator as is proven for the M.2 Type 2280-D6-M form factor module. However, for re-clocking "lock sweep" needs to be implemented in order to find the proper phase alignment. Lock sweep increases the time it takes to establish a link and lock sweep is not yet officially implemented; two reasons to use standard M.2 Type 2260-D6-M for the time being.
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**BabyWR-Carrier** is a [SPEC](https://ohwr.org/project/spec/wikis/home) like PCIe card ([Figure 3](#babywr-carrier)) that can accept a BabyWR for test purposes. Like the SPEC, BabyWR-Carrier has a PCIe interface, an SFP+ cage, a (not fully populated) LPC FMC connector, JTAG- and USB-interface, LEDs, button and GPIO headers.
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