acquisitionZONE Products for the week of October 4, 2004
National Semiconductor Corporation introduced a new family of high-precision, high-performance amplifiers to herald its entry into the burgeoning precision market. National's linear monolithic precision (LMP) line addresses existing precision applications and positions National to provide next-generation products for a market that is increasingly focused on accuracy. The first parts in the new LMP family are the LMP2011, LMP2012 and LMP2014, for broad-based applications in industrial, medical and automotive electronics.
The LMP2011/12/14 are single, dual and quad high-precision amplifiers with a very low offset voltage of 25 microvolts and wide bandwidth of 3 MHz for accurate signal amplification and reduced error for applications where DC precision and strong AC specifications are needed.
"National Semiconductor is very excited to introduce the new LMP
line and announce a new thrust area for the company," said Erroll Dietz,
vice president of National's Amplifier product group. "Our goal is
to provide customers with the highest-accuracy parts on the market, and
we're on track to do just that. Our high-performance family of analog amplifiers
not only provides very high precision over time and temperature, but also
an extended temperature range. Thanks to National's long history of innovation
in analog design, we're in a great position to support a broad range of
demanding precision applications."
analogZONE Says . . .
While the spate of op amps released in the last 15 months has been directed towards improving frequency performance, raising the bar on slew rate, and wringing performance out of minimal supply current National have gone off on a different, and highly profitable, tack. And they have kind of played low key about what they have done…
The input referred noise voltage is 35 nV/rtHz but the input referred noise from dc to 10 Hz is 850 nV p-p. No 1/f noise characteristic! How this has been done I know not, but what I do know is that the development will change low-frequency sensor designs allowing the bandwidth to be dramatically reduced.
National has gone a stage further by using a copper lead-frame for the devices removing the thermocouple noise that is produced when Kovar designs are soldered to copper traces.
One other significant specification that National has improved is the recovery time from an input overload. Typically, chopper amplifiers exhibit input overload recovery times of 200 - 300 ms; with these parts it is quoted at 50 ms and, also, the spectrum is incredibly clean up to about 30 kHz, not like any other I have ever seen. In addition the output is rail-to-rail (within 30 mV) while the supply current is a maximum 1.2 mA per channel.
The data sheet specifies the parts at both 2.7 V and 5 V although the very important crosstalk number between channels is not given. CMRR is quoted at 130 dB while PSRR is better than 120 dB. Fitting the applications these devices are likely to be used in, the gain-bandwidth product is a typical 3 MHz and the slew rate is a typical 4 V/µs.
Changing the face of low-frequency sensing is not something that happens every day. The small premium that is being charged will not deter designers from leaping at these products -- as they should.
The LMP2011/2/4 are in production with the single-channel LMP2011 in both SOT-23-5 and classic SOIC-8 priced at $0.98 in 1000-piece lots. The dual LMP2012 is in MSOP-8 priced at $1.40, also in 1000-piece lots, while the quad LMP2014 is in TSSOP-14, priced at $1.80, again in 1000-piece lots.