Datasheet AD8278, AD8279 (Analog Devices)

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Low Power, Wide Supply Range, Low Cost Difference Amplifiers, G = ½, 2 AD8278/AD8279 FEATURES FUNCTIONAL BLOCK DIAGRAMS +VS Wide input range beyond supplies 7 Rugged input overvoltage protection AD8278 Low supply current: 200 μA maximum (per amplifier) 40kΩ 20kΩ –IN 2 5 SENSE Low power dissipation: 0.5 mW at VS = 2.5 V Bandwidth: 1 MHz (G = ½) CMRR: 80 dB minimum, dc to 20 kHz (G = ½, B Grade) 6 OUT Low offset voltage drift: ±1 μV/°C maximum (B Grade) 40kΩ 20kΩ Low gain drift: 1 ppm/°C maximum (B Grade) +IN 3 1 REF Enhanced slew rate: 1.4 V/μs
01
Wide power supply range 4
0 8-
–VS
30
Single supply: 2 V to 36 V
08 Figure 1. AD8278
Dual supplies: ±2 V to ±18 V +VS 8-lead SOIC, 14-lead SOIC, and 8-lead MSOP packages 11 APPLICATIONS AD8279 40kΩ 20kΩ Voltage measurement and monitoring –INA 2 12 SENSEA Current measurement and monitoring 13 OUTA Instrumentation amplifier building block +INA 3 14 REFA Portable, battery-powered equipment 40kΩ 20kΩ Test and measurement 40kΩ 20kΩ –INB 6 10 SENSEB GENERAL DESCRIPTION 9 OUTB
The AD8278 and AD8279 are general-purpose difference amplifiers intended for precision signal conditioning in power
+INB 5 8 REFB 40kΩ 20kΩ
critical applications that require both high performance and low 8
4
05 8- power. The AD8278 and AD8279 provide exceptional common-
–VS
30 08 mode rejection ratio (80 dB) and high bandwidth while amplifying Figure 2. AD8279 input signals that are well beyond the supply rails. The on-chip
Table 1. Difference Amplifiers by Category
resistors are laser trimmed for excellent gain accuracy and high CMRR. They also have extremely low gain drift vs. temperature.
Low Distortion High Voltage Current Sensing1 Low Power
The common-mode range of the amplifier extends to almost AD8270 AD628 AD8202 (U) AD8276 triple the supply voltage (for G = ½), making the amplifer ideal AD8271 AD629 AD8203 (U) AD8277 for single-supply applications that require a high common- AD8273 AD8205 (B) mode voltage range. The internal resistors and ESD circuitry at AD8274 AD8206 (B) the inputs also provide overvoltage protection to the op amp. AMP03 AD8216 (B) The AD8278 and AD8279 can be used as difference amplifiers with 1U = unidirectional, B = bidirectional. G = ½ or G = 2. They can also be connected in a high precision, single-ended configuration for non inverting and inverting gains of The AD8278 is available in the space-saving 8-lead MSOP and −½, −2, +3, +2, +1½, +1, or +½. The AD8278 and AD8279 SOIC packages, and the AD8279 is offered in a 14-lead SOIC provide an integrated precision solution that has a smaller size, package. Both are specified for performance over the industrial lower cost, and better performance than a discrete alternative. temperature range of −40°C to +85°C and are fully RoHS compliant. The AD8278 and AD8279 operate on single supplies (2.0 V to 36 V) or dual supplies (±2 V to ±18 V). The maximum quiescent supply current is 200 μA, which is ideal for battery-operated and portable systems. For unity-gain difference amplifiers with similar performance, refer to the AD8276 and AD8277 data sheets.
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Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAMS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE MAXIMUM POWER DISSIPATION SHORT-CIRCUIT CURRENT ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION CIRCUIT INFORMATION DC Performance AC Performance DRIVING THE AD8278 AND AD8279 INPUT VOLTAGE RANGE POWER SUPPLIES APPLICATIONS INFORMATION CONFIGURATIONS DIFFERENTIAL OUTPUT INSTRUMENTATION AMPLIFIER OUTLINE DIMENSIONS ORDERING GUIDE