Hittite Microwave launches DC-20 GHz Mach-Zehnder, electro-absorptive optical modulator drivers

FEBRUARY 25, 2010 -- Hittite Microwave Corp. has introduced two new SMT-packaged optical modulator drivers, the HMC870LC5 and the HMC871LC5. The devices operate from DC to 20 GHz and are designed to drive lithium niobate Mach-Zehnder (MZ) and electro-absorptive (EA) optical modulators, respectively, with up to 8-Vp-p signals, while exhibiting low additive RMS jitter.

Hittite has targeted the devices for use in 10 Gigabit Ethernet transmitters, VSR modules, and 40-Gbps (D)QPSK modules, as well as broadband test and measurement applications.

The HMC870LC5 and HMC871LC5 are GaAs MMIC pHEMT distributed amplifiers optimized for driving MZ and EA optical modulators respectively. These drivers also provide up to 17 dB of gain and exhibit additive RMS jitter of 300 fs for 10-Gbps operation, Hittite says. Both devices are designed to support 20-Gbps operation, provide gain flatness of ±0.5 dB, and feature output swing cross point adjustment. The output swing for the HMC870LC5 is adjustable from 2.5 Vp-p to 8 Vp-p, while the output swing of the HMC871LC5 can be adjusted from 1 Vp-p to 4 Vp-p.

The HMC870LC5 and the HMC871LC5 operate over +3.3 V to +7 V and +5 V to +8 V supplies, respectively. Hittite calls them “ideal” for metro and long-haul equipment designers because they feature scalable power dissipation for varying output drive requirements. The HMC870LC5 consumes 0.4 W at 3.6 Vp-p output and less than 1 W at 8.5 Vp-p with a supply voltage of +5 V. Similarly, the HMC871LC5 consumes 0.25 W at 2.5 Vp-p output and less than 0.6 W at 4 Vp-p output with a supply voltage of +5 V.

These modulator drivers exhibit group delay flatness within ±15 ps from 1 GHz to 12 GHz signal frequency, feature edge rates of 20 ps, and exhibit excellent output slew capability over the full -40 °C to +85 °C temperature range, while requiring a minimal number of external components, Hittite asserts. Additionally, bias currents are externally adjustable for optimization of specific aspects of driver performance.

Both the HMC870LC5 and the HMC871LC5 feature RF I/Os that are internally matched to 50 ohms and are housed in leadless, ceramic 5x5 mm SMT packages. Samples and evaluation PC boards for all SMT packaged products are available from stock and can be ordered via the company’s e-commerce site or via direct purchase order.

Visit Hittite Microwave