Direct digital synthesizer enables superior recovered timing signal

27 March 2002 Telecoms, Datacoms, Wireless, IoT

In optical communications systems, there is frequently a need for recovering a timing signal from a data stream. The recovered timing signal often displays unacceptable jitter and noise characteristics. It is desirable to clean up a 'dirty' timing signal to obtain one that is jitter- and noise-free.

A common solution for cleaning up a jittery timing signal is a PLL (phase lock loop) with a suitably designed analog loop filter. This analog loop filter design must be optimised for a relatively narrow set of operating conditions. Also, this filter may be highly dependent upon the accuracy of several component values in order to achieve acceptable performance. This can make such a filter expensive and the resulting solution inflexible.

Analog Devices says that much better results can be obtained through the application of its AD9852 DDS (Direct Digital Synthesizer) in a digitally controlled oscillator (DCO) configuration. This design uses a digital processor (such as a microprocessor or DSP) to implement the PLL loop filter in software. This digital loop filter can be complex to achieve any desired transfer function, and can also be adaptable or reconfigurable for changing circumstances.

The DCO shown in the diagram takes advantage of the ultra-fine tuning resolution of the AD9852 DDS. This 300 MSa/s DDS features a 48-bit frequency tuning word that achieves 1 milli-Hz or better resolution in frequency settability. The AD9852 also features a parallel interface port that allows the controller to update its tuning value very quickly.

The combination of microhertz digital tunability and the digitally implemented PLL loop filter leads to a superior recovered timing signal and unmatched flexibility of design, according to the company.

Further reading:

The trends driving uptake of IoT Platform as a Service
Trinity IoT Editor's Choice Telecoms, Datacoms, Wireless, IoT
IoT platforms, delivered as a service, are the key that will enable enterprises to leverage a number of growing trends within the IT space, and access a range of benefits that will help them grow their businesses.

Read more...

---

RF power amplifier
RF Design Telecoms, Datacoms, Wireless, IoT
The ZHL-20M2G7025X+ from Mini-Circuits is a 32 W power amplifier that operates from 20 to 2700 MHz and delivers a saturated output power of +45 dBm.

Read more...

---

Introducing the Quectel EG800Z series
iCorp Technologies Telecoms, Datacoms, Wireless, IoT
The EG800Z series is Quectel’s latest ultra-compact LTE Cat 1 bis module, designed to deliver reliable connectivity, low power consumption, and robust performance across a wide range of IoT applications.

Read more...

---

NeoMesh on LoRa
CST Electronics Telecoms, Datacoms, Wireless, IoT
Thomas Steen Halkier, CEO of NeoCortec, recently gave a keynote speech where he spoke about “NeoMesh on LoRa: Bringing true mesh networking to the LoRa PHY”.

Read more...

---

Modules upgraded with Direct-to-Cell tech
iCorp Technologies Telecoms, Datacoms, Wireless, IoT
Quectel Wireless Solutions has announced that several of its LTE modules are now available with Direct-to-Cell (D2C) functionality, enabling devices to seamlessly connect to satellite networks.

Read more...

---

USB/Ethernet smart RF power sensor
RF Design Telecoms, Datacoms, Wireless, IoT
The PWR-18PWHS-RC from Mini-Circuits is an RF power sensor that operates from 50 MHz to 18 GHz and is designed to capture pulsed and trace modulated signals with very high data resolution.

Read more...

---

Tiny Bluetooth LE + 802.15 + NFC module
RF Design Telecoms, Datacoms, Wireless, IoT
Unleashing enhanced processing power, expanded memory, and innovative peripherals, the BL54L15µ from Ezurio is the ultimate choice for small and low power connectivity.

Read more...

---

AI modules for edge intelligence
Otto Wireless Solutions Telecoms, Datacoms, Wireless, IoT
SIMCom has introduced two new entry-level AI computing modules, the SIM8668 and SIM8666, designed to bring intelligent capabilities to lightweight, energy-efficient edge devices.

Read more...

---

High performance ISM antennas
iCorp Technologies Telecoms, Datacoms, Wireless, IoT
Quectel Wireless Solutions has announced the launch of two new high performance ISM antennas, designed to meet the need for wireless communication in devices that operate in the industrial and commercial applications.

Read more...

---

Quad-band high-precision positioning module
iCorp Technologies Telecoms, Datacoms, Wireless, IoT
Quectel Wireless Solutions has recently announced the launch of the LG680P, a multi-constellation, quad-band GNSS module designed to deliver high-precision positioning across a wide range of applications.

Read more...

---