8 to 23 GHz, 500° Time Delay/Phase Shifter
Hittite Microwave Corp. has developed a new broadband time delay/phase shifter that is ideal for clock chain and skew adjustment in 10G-RZ, 40G/100G RZ-DQPSK fiber optic applications. The HMC877LC3 is one of the first time delay/phase shifter products to provide 0 to 500° (1.4 Unit Interval) continuously adjustable delay over a wide 8 to 23 GHz frequency range. The device provides a differential output voltage with constant amplitude for single-ended or differential input voltages above the input sensitivity level. A control pin may be used to adjust the output voltage swing between 500 and 900 mVp-p.
The device provides a time delay/phase shift, which is linearly monotonic with respect to the differential delay control voltage, over a ±0.6 V tuning range. It also features internal temperature compensation and bias circuitry to minimize delay variations with temperature, ensuring an extremely stable programmable time delay over both frequency and temperature. A high delay control modulation bandwidth (3 dB rolloff point) of 2.5 GHz combined with a single +3.3 V operation also make the HMC877LC3 an excellent choice for military, space, test and measurement and broadband applications. Designed for maximum flexibility, all RF input and outputs are internally terminated with 50 Ω to Vcc and can be AC or DC coupled. Output pins can be connected directly to a 50 Ω to Vcc terminated system, while DC blocking capacitors must be used if the terminated system input is 50 Ωto a DC voltage other than Vcc.
Hittite’s broadband time delay product line also includes the HMC856LC5 and HMC910LC4B. The HMC856LC5 is a broadband time delay with a five-bit digital control that supports 28 Gbps data and provides nearly 100 ps of delay range with 3 ps resolution. This monotonic delay is DC coupled and compensated for stable operation over both power supply and temperature variation. The HMC910LC4B is a broadband time delay with 0 to 70 ps continuously adjustable delay range. The delay control is linearly monotonic with respect to the control voltage and the control input has a modulation bandwidth of 600 MHz. The HMC877LC3 supports phase alignment for clocks, while the HMC856LC5 and HMC910LC4B support serial data lane alignment in applications such as 100G DWDM transponders.
Hittite Microwave Corp.,