AD8279ARZ Datasheet, PDF (1/24 Pages) Analog Devices – Low Power, Wide Supply Range, Low Cost Difference Amplifiers,

Low Power, Wide Supply Range,
Low Cost Difference Amplifiers, G = ½, 2
AD8278/AD8279
FEATURES
Wide input range beyond supplies
Rugged input overvoltage protection
Low supply current: 200 μA maximum (per amplifier)
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)
Low offset voltage drift: ±1 μV/°C maximum (B Grade)
Low gain drift: 1 ppm/°C maximum (B Grade)
Enhanced slew rate: 1.4 V/μs
Wide power supply range
Single supply: 2 V to 36 V
Dual supplies: ±2 V to ±18 V
8-lead SOIC, 14-lead SOIC, and 8-lead MSOP packages
APPLICATIONS
Voltage measurement and monitoring
Current measurement and monitoring
Instrumentation amplifier building block
Portable, battery-powered equipment
Test and measurement
GENERAL DESCRIPTION
The AD8278 and AD8279 are general-purpose difference
amplifiers intended for precision signal conditioning in power
critical applications that require both high performance and low
power. The AD8278 and AD8279 provide exceptional common-
mode rejection ratio (80 dB) and high bandwidth while amplifying
input signals that are well beyond the supply rails. The on-chip
resistors are laser trimmed for excellent gain accuracy and high
CMRR. They also have extremely low gain drift vs. temperature.
The common-mode range of the amplifier extends to almost
triple the supply voltage (for G = ½), making the amplifer ideal
for single-supply applications that require a high common-
mode voltage range. The internal resistors and ESD circuitry at
the inputs also provide overvoltage protection to the op amp.
The AD8278 and AD8279 can be used as difference amplifiers with
G = ½ or G = 2. They can also be connected in a high precision,
single-ended configuration for non inverting and inverting gains of
−½, −2, +3, +2, +1½, +1, or +½. The AD8278 and AD8279
provide an integrated precision solution that has a smaller size,
lower cost, and better performance than a discrete alternative.
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.
Rev. C
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FUNCTIONAL BLOCK DIAGRAMS
+VS
40kΩ
–IN 2
7
AD8278
20kΩ
5 SENSE
6 OUT
40kΩ
+IN ³
20kΩ
1 _REF
–INA 2
4
–VS
Figure 1. AD8278
40kΩ
+VS
11
AD8279
20kΩ
12 SENSEA
13 OUTA
+INA ³
–INB 6
40kΩ
40kΩ
20kΩ
20kΩ
14 _REFA
10 SENSEB
9 OUTB
+INB ⁵
40kΩ
20kΩ
8 _REFB
4
–VS
Figure 2. AD8279
Table 1. Difference Amplifiers by Category
Low
Distortion
AD8270
AD8271
AD8273
AD8274
AMP03
High Voltage
AD628
AD629
Current Sensing¹
AD8202 (U)
AD8203 (U)
AD8205 (B)
AD8206 (B)
AD8216 (B)
Low Power
AD8276
AD8277
1_{U = unidirectional, B = bidirectional.}
The AD8278 is available in the space-saving 8-lead MSOP and
SOIC packages, and the AD8279 is offered in a 14-lead SOIC
package. Both are specified for performance over the industrial
temperature range of −40°C to +85°C and are fully RoHS
compliant.
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