Electronic Design


ADC Samples Input Signals At 2.5 Msignals/s With No Pipeline Delay
The LTC1411 is a 14-bit, single-supply analog-to-digital converter (ADC). It samples input signals at 2.5 Msignals/s with no pipeline delay. Its ac specifications include 80-dB SINAD and 88-dB THD. Its dc specifications include 14 bits no missing code and ±2 LSB INL.

Four programmable bipolar input ranges include ±1.8, ±1.27, ±0.9, and ±0.64 V. This lets the converter's input span be optimized to the input signal without the need for external PGAs and level-shifting circuits. The LTC1411 includes an internal precision reference that can be used for external circuitry or overridden by an external source. Power dissipation is typically 195 mW and can be reduced to 10 mW in NAP mode and 5 µW in SLEEP mode. It comes in a 36-pin SSOP package.

Versions are available for commercial and industrial temperatures. In 1000-unit lots, the device costs $18 each.

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

5-MHz Operational Amplifier Provides Rail-To-Rail Output
The MIC820 op amp provides a 5-MHz, −3-dB bandwidth while consuming only 22 µA of supply current. Requiring less space than competing devices, it features rail-to-rail output.

This device comes in the company's Teeny SC70-5 packaging. This package is half the size of an SOT23-5 package. The device is unity-gain stable and able to drive capacitive loads. It's specified for a supply voltage of 5 V. While typical input offset voltage is 1 mV, large-signal voltage gain is 72 dB. Its PSRR is 70 dB, and its CMRR is 50 dB. The MIC820 features a 5-V/µs slew rate. According to the company, this op amp suits applications such as portable equipment, cellular phones, PDAs, and MP3 players.

In 1000-unit quantities, the MIC820 op amp costs $1.02 each.

Micrel Inc., 1849 Fortune Dr., San Jose, CA 95131; (408) 944-0800; fax (408) 944-0970; www.micrel.com.

DACs Designed To Provide Wideband, Direct IF Synthesis
Two digital-to-analog converters (DACs) are designed to provide wideband, direct IF synthesis in cellular basestations. The MB86060 is a 16-bit, 100-Msample/s DAC. The MB86061 is a 12-bit, 400-Msample/s DAC.

The MB86060's interpolating filters provide an analog synthesis solution. The filters supply interpolated data to the internal DAC core at two to four times the input data rate. The MB86061 has emitter-coupled logic-compatible I/Os. It combines the low-power benefits of CMOS with the ability to interface directly to high-speed ECL circuits. Both generate signals accurately over a wide frequency band while exhibiting good spurious free dynamic range (SFDR). Typically, SFDRs of 79 dBc are achieved for a test signal generated at 20 MHz with amplitudes of −1 dBFS. An adjacent channel power ratio of 74 dB can be achieved for a W-CDMA channel synthesized directly at 32 MHz.

Both devices are fabricated using the company's 0.35-µm CMOS process for low power consumption. The MB-86060 comes in an 80-pin LQFP package. The MB86061 comes in a 64-pin QFP package. Pricing for both begins at under $44.60 each in 1000-unit quantities.

Fujitsu Microelectronics Inc., 3545 N. First St., San Jose, CA 95134-1804; (408) 922-9000; www.fujitsumicro.com.

ADC Family Includes Ultra-Low-Power 8-Bit And 10-Bit Devices
A family of high-speed CMOS analog-to-digital converters (ADCs) features ultra-low power dissipation. Fabricated in 0.25-µm CMOS technology, each device features a pipeline structure. All employ digital-error correction to achieve static linearity. Each ADC operates from a single 2.5-V supply and has a 2-V p-p differential input range.

The TSA0801 is an 8-bit device with a 40-Msample/s sampling frequency. Power dissipation is 40 mW at 40 Msamples/s. It goes beyond 7.9 effective bits at an FIN of 10 MHz. The TSA1001 is a 10-bit device with a 25-Msample/s sampling frequency. At this frequency, it dissipates 35 mW. This device goes beyond 9.8 effective bits with an FIN of 10 MHz. Designed for high-speed, low-power applications, the 10-bit TSA1002 has a 50-Msample/s sampling frequency. At this frequency, it dissipates 50 mW. This device guarantees 9.4 effective bits at an FIN of 15 MHz.

These ADCs are pin-compatible. A built-in voltage reference in each converter simplifies circuit design and minimizes external components. Designers can use external references as required. Each comes in a 7- by 7-mm, 48-pin TQFP. In 100-unit quantities, the TSA0801 costs $2.15. In similar quantities, the TSA1001 and TSA1002 cost $2.95 and $5.95 each, respectively.

STMicroelectronics Inc., Lexington Corporate Center, 10 Maguire Rd., Bldg. 1, Third Floor, Lexington, MA 02421; (781) 861-2650; www.st.com.

Single-Chip Audio CODEC Offers Built-In Digital Volume Controls
The AK4527B is a high-performance two-channel analog-to-digital converter (ADC), six-channel digital-to-analog converter (DAC), single-chip audio CODEC. This device features built-in digital volume controls for AV amplifier, digital TV, and car-audio applications.

As the successor to the AK4527, it's optimized for these applications by the addition of an overflow flag output to the ADC. This simplifies the construction of Dolby Digital systems. The AK4527B features a three-wire microcomputer interface. Since its pin allocation is nearly the same as that of its predecessor, it can be mounted with minimal pattern changes. Other features include an enhanced dual-bit Δ-Σ ADC with 64x oversampling and digital HPF for offset cancellation. It features an advanced multibit Δ-Σ DAC with 128x oversampling and a 24-bit, 8x digital filter. Single-ended outputs, channel-independent digital volume controls, and digital deemphasis are also included.

The AK4527B is available in a 44-pin LQFP package. In 1000-unit quantities, it costs $6.95 each.

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

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