0.025%までの精度を実現、PGA用高精度分圧器
SUNNYVALE, CA-December 4, 2001-Maxim Integrated Products introduces the MAX5420/MAX5421. These new devices integrate precision voltage-dividers and analog switches that are optimized for use with programmable gain amplifiers (PGAs). The MAX5420/MAX5421 provide four precision gains of 1, 2, 4, and 8 for noninverting PGA configurations, and guarantee gain accuracy to 0.025% (A grade), 0.09% (B grade), or 0.5% (C grade) over their operating temperature range. The circuits also have a very low gain temperature coefficient of less than 1ppm/°C. The MAX5420/MAX5421 can be used in applications such as gain control of inverting and noninverting amplifiers and programmable instrumentation amplifiers. The MAX5420 is offered in an 8-pin µMAX package, allowing for significant board-space reductions, while the MAX5421 comes in a 10-pin µMAX package.
The MAX5420/MAX5421 integrate the precision resistors and analog switches needed to implement PGAs. An op amp has not been included to allow the user to choose the ideal op amp for his/her application. The MAX5421 provides cancellation of offset voltages caused by op amp input bias currents. This is achieved, independent of gain setting, by matching the impedances of both amplifier inputs.
The MAX5420/MAX5421 use less than 7mA supply current when idle, operate from single +2.7V to +5.5V supplies or dual ±5V supplies, and use a simple 2-wire parallel interface to set divider ratios.
Prices for the MAX5420/MAX5421 start at $1.26 and $1.43, respectively. All prices are for C grade (1000-up, FOB USA).
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