EDN — 07.04.96 Integrated Circuits

Integrated Circuits: July 4, 1996

Monolithic SMDS ICs conserve power, space.

Re-ducing the cost and power requirements of switched-multimegabit-data-services (SMDS) equipment, the Bt8209 and Bt8210 SMDS control- and reassembly-formatter chips operate at full DS3 rates. The chips dissipate only 1W for T3 rates and 0.5W for T1 rates. The devices execute the full range of SMDS functions, including the reassembly of up to 126 simultaneous Level 3 messages. The chips also have programmable support for all popular Physical Layer Convergence Protocol formats: T1 and E1 in the Bt8209, expanding to T3 and E3 in the Bt8210. Respective prices for the Bt8209 and Bt8210 are $162 (1000) and $240 (1000). Brooktree Corp, San Diego, CA. (619) 452-7580.

DC/DC converter serves Pentium Pro designs.

The RC5042 dc/dc converter provides the necessary supply voltages for Pentium Pro processors from a 5V input and requires only minimal external components. Output voltage is programmable from 2.1 to 3.5V in 100-mV increments. You can externally adjust the oscillator frequency from 200 kHz to 1.2 MHz by varying one capacitor in the application circuit. You can configure the RC5042 to deliver load currents from a few mA to >11.2A with 85% efficiency. The device comes in a 16-lead SOIC and costs $3.20 (10,000). Raytheon Company, Semiconductor Division, Mountain View, CA. (415) 968-9211.

Telecom IC saves space in DAA circuits.

Requiring 60% less board space than conventional discrete de-signs, the ITC117P telecom IC for data-access-arrangement (DAA) circuits combines optically coupled MOSFETs, a bridge rectifier, Darlington transistor, and an optocoupler in a 16-pin SOIC package. The MOSFETs function as a 2-mW hookswitch in the DAA circuit, with a blocking voltage of up to 3500V, an isolation voltage to 3750V rms, and an on-resistance of 15V. The optocoupler can function as a ring detector or as a loop-current detector. The ITC117P costs $4.18 (10,000). CP Clare Corp, Semiconductor Group, Wakefield MA. (617) 246-4000.

RDRAM serves as 1-Mbyte graphics frame buffer.

Targeting the PC graphics market, the 8-Mbit TC59R0808HK Rambus DRAM (RDRAM) feeds 1024×768-pixel color displays with 256 colors and provides sufficient bandwidth to display 3-D graphics and full-motion video. The part, which can be used as a 1-Mbyte frame buffer, operates at 3.3V with a typical power consumption of 550 mW in active mode, 220 mW in standby mode, and 0.33 mW in power-down mode. Housed in a 32-pin surface horizontal package, the memory device samples for $40. Toshiba America Electronic Components Inc, Irvine, CA. (800) 879-4963.

Tiny charge-pump IC plays low-current step-up converter.

Housed in the vendor's IttyBitty five-lead SOT-23-5, the MIC2660 charge pump provides stepped-up unregulated voltage with no external components in a package, which is half the footprint of an eight-pin SOIC. Without the use of external filter capacitors, the device delivers 5V at 3 mA from a 3V input or 11V at 3 mA from a 5V supply. With the enable pin off and no load, quiescent current is below 1.5 mµ. At a height of 1.2 mm, the MIC2660 easily fits into Type I, II, or III PC Cards. The part costs $0.71 (3000). Micrel Semiconductor Inc, San Jose, CA. (408) 944-0800.

Current-feedback amp drives telecom and video loads.

Operating with a 60-MHz gain-independent bandwidth, the LT1207 dual-current-feedback amp targets telecom and video-distribution applications. The device delivers an output current of 250 mA minimum and offers a slew rate of 900 V/µsec, differential gain of 0.02% typ, and differential phase of 0.178 typ. The amp also provides a pin for an optional compensation network, which stabilizes the amp for heavy capacitive loads. The LT1207 comes in a 16-lead SO package and operates from ±5 to ±15V supplies. The amp costs $6.90 (1000). Linear Technology Corp, Milpitas, CA. (408) 432-1900. Circle No. 369

Power-conversion IC switches at up to 1 MHz.

A high-frequency monolithic power-conversion IC for fixed- network communications devices that require up to 10W contains the active circuitry to replace a dc/dc module. Running directly off standard telephone-line power, the Si9117DY operates at switching frequencies of up to 1 MHz and includes a 1(ohm), 200V switching FET in its SOIC-16 package. The part also offers soft-start, internal-start-up, and latched-shutdown circuitry. The Si9117DY costs $2.65 (100,000). Siliconix, Santa Clara, CA. (800) 554-5565, ext 81.

Module mixes SRAM and flash memory.

The WSF128K×2-22H2X combines 4 Mbits of SRAM and 4 Mbits of flash memory in a 66-pin PGA-type package, replacing eight monolithic devices. Both SRAM and flash are organized as 128k332 bits with a common data bus. Maximum access times are 25 and 120 nsec for the SRAM and flash, respectively. An operating temperature range of -55 to +125°C provides high reliability for military applications. Prices start at $700 (OEM). White Microelectronics, Phoenix, AZ. (602) 437-1520.

Low-dropout linear regulators sport SOT-23 packages.

Two linear regulators, the MAX8863T/S and MAX8864T/S, offer dual-mode operation. The regulators supply an adjustable output of 1.25 to 5.5V or a preselected output for load currents of 100 mA (3.175V for the T versions or 2.85V for the S versions). Housed in five-pin SOT-23 packages, the regulators comprise a 1.25V reference, an error amplifier, a MOSFET driver, a p-channel pass transistor, a dual-mode comparator, and an internal-feedback voltage divider. Dropout voltage is only 60 mV at 50-mA I_out. The PMOS pass transistor keeps the 100-µA supply current independent of the load. Prices start at $0.75 (1000). Maxim Integrated Products, Sunnyvale, CA. (408) 737-7600, ext 6087.

Power transistor operates from 800 to 970 MHz.

The MRF897R RF power transistor is useful for large-signal, common-emitter, class AB linear- amplification applications in industrial and commercial AM/FM equipment. The transistor provides an output of 30W over a frequency range of 800 to 970 MHz. The device also has a minimum power gain of 10.5 dB and a maximum intermodulation distortion of -30 dBc at 30W. Minimum efficiency is 30% at 900 MHz and 30W. The MRF897R costs $127.82 in low volume. Motorola Semiconductor Products Sector, Phoenix, AZ. (602) 244-6108.

Voltage-reference IC occupies <0.01 in.².

The LM4040 and LM4041 voltage references can replace other types of two- and three-terminal references currently available only in larger packages. The IttyBitty devices, which require <0.01-in.² surface area and come in the vendor's IttyBitty SOT-23 packages, have temperature coefficients of <100 ppm/8C across the operating-temperature range of -40 to +85°C. The LM4040 series comes in 2.5, 4.096, 5, and 10V fixed versions. The LM4041 offers 1.225V and adjustable versions. References are available with accuracies of 0.5% to 2%. Prices start at $0.72 (100). Micrel Semiconductor Inc, San Jose, CA. (408) 944-0800.

TQFP analog switch handles 180V pk-pk.

With a high-voltage rating of 200V, the eight-channel HV202 switches analog signals as high as 180V pk-pk and comes in a 48-pin TQFP. Each channel has a switch resistance of 24(ohm) maximum at a signal current of 200 mA and 100V. Switch crosstalk is 60-dB minimum and off-isolation is 58-dB minimum. Quiescent current is 10 µA for the high-voltage supply. The logic section of the IC operates at 5V and consists of an 8-bit shift register and latches. In addition to TQFP, the HV202 comes in a 28-pin PLCC, as well as in die form. TQFP pricing is $25.85 (1000). Supertex Inc, Sunnyvale, CA. (408) 744-0100.

14-bit sampling ADC guarantees no missing codes.

Operating over the full military temperature range of -55 to +125°C, the ADS-919 14-bit ADC samples at a rate of 2 MHz and guarantees no missing codes to the 14-bit level. Signal-to-noise ratio is 77 dB and total harmonic distortion is -74 dB. Pin-compatible with its slower predecessors, the ADS-919 is a drop-in replacement for 916/917-based systems. The converter requires ±15V (or ±12V) and +5V supplies, typically dissipating 1.8W (or 1.5W). The ADS-919 comes in 24-pin DDIPs. The military version costs $377 (100), and the commercial version costs $282 (100). Datel Inc, Mansfield, MA. (508) 339-3000.

Multimedia op amp has 150-MHz bandwidth.

Operating at 150 MHz and slewing 110V/µsec, the TSH94 quad op amp is a good choice for demanding video applications. Other high-performance video specifications include a differential phase of 0.07°, differential gain of 0.03%, and 0.1-dB maximum gain flatness at 6 MHz. The TSH94 also provides a low-noise figure of 4.2 nV/[square root]Hz and a total harmonic distortion of only 0.01% at 1 kHz. Current consumption is typically 4.5 mA per op amp at 150 MHz. The device costs $1.25 (1000). SGS-Thomson Microelectronics, Lincoln, MA. (617) 259-0300.