Electronic Design


Tiny Termination Array Combines 32 Resistors For 16 Channels
The CSPDDR100, a double-data-rate (DDR) or series stub terminated logic (SSTL) termination array, was designed for use in computers, network infrastructure equipment, and graphics accelerator cards. It provides an integrated solution in chip-scale-package (CSP) format for DDR and SSTL bus terminations where series and parallel termination resistors are both required. Also, it combines 32 resistors for a total of 16 termination channels in a 5.79- by 2.44-mm footprint.

According to its manufacturer, the CSPDDR100 meets requirements for emerging DDR RAMs and other systems using SSTL termination structures. State-of-the-art thin-film technology supplies greater than 3 GHz of performance. Its resistors are trimmed to an absolute tolerance of ±1% over temperature. By using this array in a high-speed memory system, designers can reduce ringing on transmission lines and crosstalk between lines. They also can increase noise margins and minimize EMI/RFI emission problems.

In 100,000-unit quantities, the CSPDDR100 costs $0.41 each. Samples are now available. Lead time is six to eight weeks ARO.

California Micro Devices, 215 Topaz St., Milpitas, CA 95035; (408) 263-3214; fax (408) 263-7846; www.calmicro.com.

Dual Analog Switches Squeeze Into Small, 8-Lead Packages
The NC7WB66K8 TinyLogic family member squeezes a pair of analog switches into the industry's smallest 8-lead package, the US8. The dual switch is implemented as two separate N- and P-channel CMOS pairs, and it includes independent enable lines. The pass-gate switches operate over a 1.65- to 5.5-V supply range and deliver an on-resistance flatness of 8 Ω across a peak-to-peak signal range of 0 to 3 V. Additionally, the switches are matched for on-resistance to within 0.2 Ω.

Other analog specifications include a crosstalk between channels of −70 dB at 10 MHz and a 3-dB bandwidth of 200 MHz, when measured with an RL of 50 Ω and a CL of just 8 pF. When idle, the chip draws just 1 µA of quiescent current. The 2.1- by 3.1-mm package requires minimal board space, permitting the switch chip to squeeze into systems such as cell phones, digital cameras, PDAs, and PCMCIA cards.

In lots of 3000 units, the dual-switch chip sells for $0.40 each. Samples and production quantities are immediately available.

Fairchild Semiconductor International, 333 Western Ave., South Portland, ME 04106; (888) 522-5372; fax (207) 761-6020; www.fairchildsemi.com/pf/nc/nc7wb66.html.

Low-Power Instrumentation Amplifier Provides Precision And Protection
The LT1168 instrumentation amplifier combines dc precision with industrial-strength input fault protection. It can withstand ±100-V dc input faults and electrostatic discharge spikes over 8 kV with external 5-kΩ input resistors. Also, this device is linear to better than 20 ppm. It operates from ±2.3 to ±18 V, and it has a typical quiescent current of 350 µA. Its input bias referred current is less than 250 pA, with an offset current of less than 300 pA. Total input offset voltage is less than 60 µV at a gain of 10.

Operating at a gain of 1000, its gain nonlinearity is better than 40 ppm. For gains of 1 to 1000, the gain error is less than 0.5%, making the gain set resistor tolerance the dominant source of gain error. Input offset drift is less than 0.3 µV/°C, and maximum output offset drift is 3 µV/°C. With this input and output precision, designers don't need to perform the kind of extensive system calibration that's necessary with other instrumentation amplifiers. Designers also can set gain from 1 to 10,000 with a single external resistor.

Fully specified from −40°C to 85°C, the LT1168 is available in 8-pin compact surface-mount and plastic dip packages. It starts at $3.70 each in 1000-unit quantities.

Linear Technology Corp., 1630 McCarthy Blvd., Milpitas, CA 95035-7417; (408) 432-1900; fax (408) 434-6441; www.linear-tech.com.

250-MHz Operational Amplifiers Achieve −88 dBc SFDR At 5 MHz
Available in SOT23-6 packages, the MAX4285, 4288, 4387, and 4388 single-supply, 250-MHz op amps offer an SFDR of ­88 dBc at 5 MHz. These devices operate on supply voltages ranging from 2.85- to 6.5-V single supplies or ±1.425- to ±3.25-V dual supplies. Other features include a ­3-dB bandwidth of 200 MHz, a slew rate of 350 V/µs, and an output current drive up to 100 mA. All of the op amps have a low-power disable mode that reduces supply current and places the outputs in a high-impedance state. They come in six-pin SOT23, eight- and 14-pin SO, and eight- and 10-pin µMAX packages.

Prices start from $0.89 each in 1000-unit quantities.

Maxim Integrated Products, 120 San Gabriel Dr., Sunnyvale, CA 94086; (800) 998-8800; fax (408) 737-7194; Internet: www.maxim-ic.com.

Data-Acquisition Module Measures 11 12-Bit Analog-To-Digital Signals
The ADC-11/12 data-acquisition module is now available in a 12-bit version, providing PCs with 0.5% accuracy and 0.61-mV resolution. This device connects with a desktop or laptop PC's parallel port and supplies 11 channels of analog input in a matchbox-sized case. Also, it offers 1/4096 accuracy without needing a power supply.

Designers can use the PicoLog software, which comes free with the ADC-11/12, to replace costly chart recorders and plug-in data-acquisition boards. Meanwhile, the module can record at 10,000 samples/s. An optional terminal board converts the DB-25 input connector into screw terminals to simplify connection to the converter inputs.

Available from stock, the ADC-11/12 costs $249.

Saelig Co., 1193 Moseley Rd., Victor, NY 14564; (716) 425-3753; fax (716) 425-3835; www.saelig.com.

Low-Power, 24-Bit ADC Includes A 32-Level Δ−Σ Modulator
Housed in a 16-pin TSSOP package, the AK4382 analog-to-digital converter (DAC) provides 112-dB, 24-bit performance. This 192-kHz DAC features an advanced 32-level, multibit delta-sigma (Δ−Σ) modulator. Its switched-capacitor technology provides jitter-tolerant performance as well. Other features include full differential outputs, a built-in de-emphasis filter, soft mute, left and right independent zero detection pins, independent digital ATT, and low power consumption.

Engineering samples are now available. Contact the company for pricing information.

AKM Semiconductor, 2001 Gateway Pl., Ste. 650W, San Jose, CA 95110; (408) 436-8580; fax (408) 436-7591; www.akm.com.

Low-Cost ADC Hits 250 Msamples/s And Dissipates 310 mW Of Power
The SPT7721 analog-to-digital converter (ADC) dissipates 310 mW of power. This 8-bit device's flexible output interface lets designers demultiplex digital outputs for parallel-aligned or interleaved data output. Its 250-Msample/s rate allows engineers to accurately digitize complex analog signals. Operating between −40°C and 85°C, it's packaged in a 44-lead TQFP surface-mount package. Its manufacturer says that it's well suited for cost- and power-sensitive communications applications, such as wireless local loops and wireless network applications.

This ADC costs $15 each in 1000-unit quantities.

Signal Processing Technologies Inc., Marketing Communications Dept., 4755 Forge Rd., Colorado Springs, CO 80907; (800) 643-3SPT; fax (719) 528-2300; www.spt.com.

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