Microwave Engineering Europe - June 2008 - (Page 14)

14 COVER FEATURE — HIGH SPEED LOGIC a typical propagation delay of 60 ps, and typical rise and fall times of 20 ps while dissipating only 180 mW. The HMC672LC3C may be conﬁgured to provide either AND, NAND, OR or NOR logic functions, providing system designers with maximum utility from a single device part number. When this device is conﬁgured as an AND gate, it may be used to gate high speed clock or data signals. The HMC672LC3C is ideal for this application, since it provides high isolation of 50 dB in the off mode. The device also exhibits typical rise and fall times of 20 ps, and less than 1 ps of deterministic jitter while dissipating only 180 mW. The HMC673LC3C D-Type Flip Flop is also designed to support data transmission rates up to 13 Gbps, and clock rates up to 13 GHz. During normal operation, the data is transferred to the outputs on the positive edge of the clock, but for application ﬂexibility, the clock inputs may also be reversed to support negative-edge triggered applications. This device also exhibits a very low set up and hold time of less than 6 ps. The HMC673LC3C also provides an excellent clock phase margin speciﬁcation of 320 degrees at 13 GHz. This phase margin speciﬁcation is signiﬁcantly better than competing products, and permits very robust system timing, allowing for a very large range of clock data drift. Since the HMC673LC3C exhibits less than 1 ps of deterministic jitter and provides a propagation delay of 55 ps, this device may also be used in a wide range of applications where data bit streams need to be retimed as they travel across high speed system backplanes (Figure 1). The rise and fall times are typically 20 ps, and the device typically dissipates 210 mW. Figure 2 displays a HMC673LC3C eye diagram using an Agilent N4901B Serial BERT with a 12 Gbps, 215-1 PRBS data pattern captured on a Tektronix CSA8000 at room temperature (25 °C). These high performance logic devices all feature an output level control pin, VR, which permits signal loss compensation, which can occur when very high speed signals travel over transmission lines. This feature is also ideal for signal level optimization. In this way, the signal output level could be reduced to generate lower output voltage swings, permitting faster rise time and lower propagation delay. The output signal level can be adjusted by either applying a voltage directly to VR, or by connecting the pin to ground with a suitable resistor value. In some applications this voltage may be accurately provided by a lowcost DAC. The programmable differential output voltage swing may be set anywhere in the range from 0.4 V to 1.1 V. The current mode logic (CML) inputs and outputs of this family of logic devices provide a wide common mode operating range. These devices can accommodate input signals in the range of -1.5 V to +0.5 V, and can operate with a dc supply in the range of -3.0 V to -3.6 V. These devices also feature over-voltage protection on the power supply and ground pins, and all of the inputs and outputs are ESD protected. As shown in Figure 3, these 13 Gbps logic devices may be used to support a wide range of termination schemes accommodating both positive and negative dc supplies as well as ac and dc coupling requirements. The devices feature differential inputs and outputs which are DC coupled and terminated on chip with 50 Ohm resistors to ground. The inputs or outputs may be used in either single-ended or differential modes. The HMC670LC3C, HMC671LC3C, HMC672LC3C and the HMC673LC3C logic Figure 2: HMC673LC3C Eye Diagram. devices represent the ﬁrst products in the family, and additional 13 Gbps products with complementary functions will be released in the coming months. Designers looking for versions of these products with alternate pinouts or alternate dc power supply voltages should contact Hittite Microwave directly. Multiple logic functions may also be combined to provide products with higher levels of integration, and these may be made available in SMT packages or module format to meet the needs of custom applications. The HMC670LC3C, HMC671LC3C, HMC672LC3C and the HMC673LC3C are speciﬁed for operation from -40 °C to +85 °C, and are housed in ceramic RoHS compliant 3 x 3 mm SMT packages. These products can be ordered via the company’s e-commerce site, or via direct purchase order. Released data sheets are available online at www.hittite.com. Figure 3: High speed logic showing various interfacing termination schemes and power supply voltages. Microwave Engineering Europe ● June 2008 ● www.mwee.com http://www.hittite.com http://www.mwee.com

Table of Contents Feed for the Digital Edition of Microwave Engineering Europe - June 2008

Microwave Engineering Europe - June 2008 Contents Comment News Cover Feature Designing and Simulating a Wireless LAN Antenna 60GHz: Achieving the Ultimate Wireless Dream New Radar Developments Include HFETs to Challenge DMOS/LDMOS and a 77-GHz CMOS PA for Automotive Applications Testing Raises Concerns Over 802.11-Based High-Speed Bluetooth IP2 & IP3 Design Considerations with Direct Conversion I/Q Demodulator Receiver Products Calendar

Microwave Engineering Europe - June 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.