acquisitionZONE Products for the week of August 11, 2003
Microchip Technology Inc., a leading provider of microntrollers and analog semiconductors, announced three operational amplifier (op amp) families featuring extended industrial temperature range (-40-degrees Celsius to +125-degrees Celsius) and input/output rail-to-rail functionality. These are general-purpose op amps ideal for many diverse markets, specifically in automotive, industrial and other appliances where higher temperature is expected.
These multiple Gain Bandwidth Product (GBWP) op amps have a low-supply current requirement, which enables an efficient current-flow design. With an offering at 2MHz, 5MHz and 10MHz GBWP, the engineers have a migration path to maximize their designs for best bandwidth vs. supply current. This path along the GBWP spectrum is available for amplifiers with the same general performance making it easier to change or improve designs.
These op amp families are designed with Microchip's advanced CMOS process and provide a wide bandwidth for the current. Additionally, they support both input and output rail-to-rail swing. Microchip's MCP6271/2/3/4 family has a 2MHz-gain bandwidth and a 65-degree phase margin. They operate from a single-supply voltage as low as 2.0V, while drawing a 170uA (typical) quiescent current at 5.5V.
The MCP6281/2/3/4 family has a 5MHz-gain bandwidth and 65-degree phase margin. This family operates from a single-supply voltage as low as 2.2V, while drawing 450uA (typical) quiescent current at 5.5V.
Microchip's MCP6291/2/3/4 family has a 10MHz-gain bandwidth product and
65-degree phase margin. This family also operates from a single-supply voltage
as low as 2.4V, while drawing 1mA (typical) quiescent current at 5.5V.
analogZONE Says . . .
If you search for an op amp -- in a CMOS voltage range -- that has better than 2 MHz GBW, rail-to-rail on both input and output, plus a shutdown facility you end up with very few parts to choose from. If you then start to look at other characteristics you will find that these Microchip parts stand out for their low quiescent while their thermal offsets and noise are right where you would expect them to be. Slew rates are slightly slower than you would expect for the bandwidths but the killer numbers are for CMRR -- which are typically better than 80 dB for a common-mode voltage range from -0.3 V to 5.3 V (with a 5.0 V rail) and I am more than a little surprised that Microchip doesn't make a bigger deal out of it!
The three families of parts have specifications that track very well, independent of the differing GBWs and slew rates. There is a small discrepancy in PSRR for the MCP628x family compared to the other two and input noise density is quoted for the MCP629x family at 10 kHz instead of 1 kHz -- which would be a minor difference in the number anyway.
Input offset voltages are better than ±5 mV over the extended temperature range with a typical PSRR of 90 dB. The dc open-loop large signal gain is a typical 110 dB while the output short-circuit current is ±25 mA. In the multiple channel parts the isolation between amplifiers appears to be better than 135 dB out to 10 kHz and drops to about 110 dB at 100 kHz.
The supply rail can operate from +2.0 V to +5.5 V with the data quoted as being applicable across the entire span. Typical quiescent for the families (per amplifier) are 170 µA for the MCP627x, 450 µA for the MCP628x and 1.0 mA for the MCP329x parts. The corresponding GBWs and slew rates are 2.0 MHz and 0.9 V/µs, 5.0 MHz and 2.5 V/µs, and 10.0 MHz and 7 v/µs. The phase margin throughout is a typical 65 degrees at unity gain. The shut-down (chip select) parts -- the MCP6273/83/93 -- have a quiescent of typically 0.7 µA when the parts are shut down.
When the input voltage range exceeds the rails by more than 300 mV it can cause reliability problems but there is no phase reversal of the signals. The output rail-to-rail performance is within 15 mV of both rails.
These parts are ideal for Microchip's main market thrusts in signal paths to feed ADCs and subsequent PIC processing. They offer extremely good performance for lower frequency applications such as audio filters, sensor inputs and general-purpose use in all sorts of battery-powered equipment, the rail-to-rail input giving them a noise advantage -- and the pricing is, simply, aggressive.
The singles, including the parts with shutdown, and the duals are sampling in PDIP-8, SOIC-8 and MSOP-8, while the quads are in PDIP-14, SOIC-14 and TSSOP-14 with standard pin-outs. 1000-piece pricing is $0.39 for the MCP6271, $0.51 for the MCP6272, $0.40 for the MCP6273, and $0.93 for the MCP6274. Similarly the MCP6281 is $0.46, the MCP6282 is $061, the MCP6283 is $0.48 and the MCP6284 is $1.06. The MCP6291 is $0.50, the MCP6292 is $0.67, the MCP6293 is $0.53 and the MCP6294 is $1.17, again in 1000-piece lots. Volume production is scheduled for later this month.
Data Sheet (MCP6271/2/3/4)
Data Sheet (MCP6281/2/3/4)
Data Sheet (MCP6291/2/3/4)