Electronic Design


ESD-Protected Analog Multiplexers Are Able To Tolerate Radiation
The ACT8500 analog multiplexer module series meets the aerospace industry's increasing demand for commercially available off-the-shelf (COTS) solutions. Features include optimized size and weight performance and electrostatic discharge (ESD). Family members are offered in 48- and 64-channel configurations using various industry-approved 1840 radiation-tolerant multiplexer ICs. These transmit signals to subsystems for monitoring. ACT8500 devices are capable of a radiation tolerance up to 300 Krads (Si).

Some models offer benefits such as power-supply decoupling capacitors, a 1500-ns access time, and low power consumption (less than 90 mW). The units function from −55°C to 125°C.

Pending successful completion of QCI, the ACT8500 multiplexers will be available at the end of the year. Flight-quality units are priced between $3100 and $3900. Nonflight-quality parts cost about $2300 to $2850.

Aeroflex Circuit Technology, 35 S. Service Rd., Plainview, NY 11803; (516) 694-6700; fax (516) 694-4823; www.aeroflex.com.

Single-Channel ADC Built For Use With USB Microphones
A 16-bit single-channel analog-to-digital converter (ADC), the AK5370 is available with a built-in USB interface for microphones. The device also possesses essential USB microphone characteristics such as a USB transceiver and programmable gain amplifier. Other attributes include controllable-from-the-host USB audio-class command processing circuits, FIFO for isochronous transfer, and a mic bias control circuit. All of these functions are realized on one chip.

Another one of this converter's advantages is that it comes with a programmable gain amp controllable from the host over a range of 20 to −58 dB in 1-dB steps. It also features mute/volume control, sampling frequency control, an AGC pin for external control, and pre-amp (variable with external resistors). Furthermore, it maintains an operating power voltage of 3.3 V at 10%.

Available in 24-pin VSOP packaging, samples of the AK5370 are now available. Prices are set at $5.51 in 10,000-piece quantities.

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

New Rail-To-Rail Op Amps Provide Existing Amplifiers With An Upgrade
A pair of op amps, the EL5410C quad and the EL5210C dual, offers increased slew rate, low power consumption, and rail-to-rail operation. As a result, the devices prove beneficial in many areas, such as TFT-LCD buffering, ADC/DAC interfacing, and typical video applications. Featuring a 30-MHz bandwidth, both op amps function from only 2.5 mA per unit. Also, they boast rail-to-rail input and output capabilities.

Available in TSSOP and SOIC packaging, the EL5410C is priced at $1.75 in 10,000-piece quantities. The dual EL5210C comes in either an MSOP or SOIC package and can be obtained for $1.50 in 10,000-piece quantities.

Elantec Semiconductor Inc., 675 Trade Zone Blvd., Milipitas, CA 95035; (408) 945-1323; fax (408) 945-9305; www.elantec.com.

DACs Designed To Enhance DVD And Other Audio Applications
The AD1852 and AD1854 are recent arrivals in the audio digital-to-analog converter (DAC) arena. Featuring a THD+N of −97 to −104 dB, they enhance the performance of DVD and other audio applications.

A 24-bit stereo audio DAC, the AD1852 relies on proprietary data conversion, greatly improving audio performance at sample rates from 32 to 192 kHz. It's fully compatible with all existing DVD formats and sample rates. Furthermore, it's backward compatible, supporting the 50-/15-µs digital re-emphasis designed for compact discs.

Offered in two performance grades, the AD1854 is a single-chip stereo digital audio playback system able to sample data at 16, 18, 20, or 24 bits. Model AD1854KRS can reach a dynamic range of 113 dB. It also features a signal-to-noise ratio (not muted) at 48 kHz and raises THD+N to −100 dB. In comparison, the AD1854JRS achieves a 108-dB dynamic range, a signal-to-noise ratio of 48 kHz, and −97-dB THD+N.

Packaged in a 28-pin SSOP, the AD1852 operates from a single 5-V power supply and is priced at $4.50 in 10,000-piece quantities. Models AD1854KRS and AD1854JRS, also offered in 10,000-piece quantities, cost $3.95 and $2.95, respectively.

Analog Devices Inc., 804 Woburn St., Wilmington, MA 01887; (781) 937-1428; fax (781) 937-1021; www.analog.com.

Synchronous Buck Designers Obtain Higher Efficiency At Low Voltages
A 30-V n-channel FETKY, the IRF7901D1 improves power density and efficiency in 1-V buck dc-dc converters. This development integrates a high-side control FET, a low-side synchronous FET, and parallel Schottky diodes in a single SO-8 package. It can also achieve as high as 87% efficiency for applications requiring up to 5-A peak at 1-V output.

All of the IRF7901D1's power components are internally connected. As a result, the stray inductance that would occur in a discrete solution board layout is greatly decreased. Another advantage of this dual FETKY is that it provides source and gate pins. This helps minimize control-loop inductance for better gate drive.

Offered in SO-8 packaging, the IRF7901D1 can be obtained for $0.65 in quantities of 100,000.

International Rectifier, 233 Kansas St., El Segundo, CA 90245; (310) 252-7105; www.irf.com.

Output Sensor-Signal Conditioner Helps Produce 1% Accurate Sensors
A sensor-signal conditioning product, the MAX1459, can accommodate nonlinearities of piezoresistive transducers to better than 1% accuracy. It also features an uncommitted op amp that can be configured to provide a 4- to 20-mA industrial interface or the diagnostic clip voltages typically required by automakers. Additionally, this device can compensate nonbulk, micromachined sensors, strain gauges, or comparable resistive-based sensors.

Using electronic trimming, the MAX1459 significantly reduces manual production content, simplifying the manufacture of sensor modules. Another benefit of this product is that it contains a complete analog signal path with integrated digital correction through four internal 12-bit digital-to-analog converters (DACs). These DACs can be programmed to correct for span, span TC, offset, and offset TC. A fifth low-resolution DAC helps rectify course offset. The MAX1459 can be programmed via a digital interface. Correction coefficients are contained in the device's internal EEPROM sensors.

Available in compact 20-pin SSOP packaging, the MAX1459 costs $2.95 and above.

Maxim Integrated Products, 120 San Gabriel Dr., Sunnyvale, CA 94086; (800) 998-8800; www.maxim-ic.com.

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