Two high speed op amps from Micrel -- MIC918 and MIC919 -- achieve a slew-rate of 1500V/us while consuming just 550uA and 360uA, respectively. Micrel Semiconductor is an industry leader in analog and broadband communications integrated circuits.

Both op amps are voltage-feedback, unity-gain stable devices and are housed in SC70-5 packaging. The MIC918 has a gain-bandwidth product of 51MHz and the MIC919 has a gain-bandwidth product of 27MHz. As with all other members of Micrel's MIC91x op amp family, they achieve higher speed at lower power than competing devices.

"No other op amps available today are close to achieving this combination of power consumption and speed," said Scott Brown, Linear and RF Business Unit Manager. "Earlier op amps in this series optimized gain-bandwidth product. These latest additions are optimized for maximum slew-rate. With the MIC918 and MIC919, we have dramatically increased slew-rate while significantly reducing supply current."

Stability -- often an issue for high speed op amps -- is excellent in all MIC91x parts. They were designed from the beginning for stable operation and ease of use and are capable of driving loads of any capacitance. The MIC918 and MIC919 have 60 degrees of phase margin at unity gain and this actually increases with load capacitance.

The MIC918 and MIC919 are specified for supply voltages of +/-5V and +/-9V. PSRR is 104dB for the MIC918 and 105dB for the MIC919, and CMRR is 91dB for the MIC918 and 87dB for the MIC919. AVOL is 93dB for the MIC918 and 92dB for the MIC919.

Summary of Features & Applications:

MIC918 and MIC919 High Speed Op Amps High slew rate: 1500V/us, low power consumption, 550uA supply current (MIC918), 360uA supply current (MIC919), supply voltages from +/-2.5V to +/-9V, unity-gain stable, drive loads of unlimited capacitance, and SC70-5 packaging. Applications include, portable instrumentation, medical equipment, video / imaging.

Micrel Semiconductor, Inc., 1849 Fortune Drive, San Jose, CA 95131. Phone: 408-944-0800. Web: http://www.micrel.com

These parts are ideal for video driving long coaxial cable lengths, as general line drivers, and because of the low current consumption they will find a home in a lot of portable equipment. An important feature of both the MIC918 and MIC919 products are their ability to be stable even when driving high capacitance, which is just what you need for driving long coaxial cables or other high-capacitance loads. Most high-speed op amps are only able to drive limited capacitance. However, increasing load capacitance does reduce the speed of the device. In situations where the load capacitance reduces the speed of the op amp to an unacceptable level, the company states that you can reduce the effect of the load capacitance simply by adding a small resistor (<100 ohms) in series with the output. Unlike previous members of this op amp series that were optimized for gain-bandwidth, these are honed for high slew-rate, with a major reduction of supply current.

The SC-70 package, like all small packages, has a high thermal resistance. It is important to ensure the IC does not exceed the maximum operating junction temperature of 85 degrees C. The part can be operated up to the absolute maximum temperature rating of 125 degrees C. But between 85 and 125 degrees C performance will degrade, in particular current mode rejection ratio will reduce.

The MIC918 and MIC919 are provided in SC70-5 packaging and are priced at $1.40 in 1k quantities. Samples are available immediately, and production quantities are available in 8 weeks ARO.

Data sheets:
MIC918
MIC919