1 μA Micropower CMOS

Operational Amplifiers

AD8502/AD8504

Rev. A

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FEATURES

Supply current: 1 μA maximum/amplifier

Offset voltage: 3 mV maximum

Single-supply or dual-supply operation

Rail-to-rail input and output

No phase reversal

Unity gain stable

APPLICATIONS

Portable equipment

Remote sensors

Low power filters

Threshold detectors

Current sensing

PIN CONFIGURATIONS

OUT A 1

–IN A 2

+IN A 3

V– 4

V+

8

OUT B

7

–IN B

6

+IN B

5

AD8502

TOP VIEW

(Not to Scale)

Figure 1. 8-Lead SOT-23

1

2

3

4

5

6

7

AD8504

–IN A

+IN A

V+

OUT B

–IN B

+IN B

OUT A

14

13

12

11

10

9

8

–IN D

+IN D

V–

OUT C

–IN C

+IN C

OUT D

TOP VIEW

(Not to Scale)

Figure 2. 14-Lead TSSOP (RU-14)

GENERAL DESCRIPTION

The AD8502/AD8504 are low power, precision CMOS operational

amplifiers featuring a maximum supply current of 1 μA per

amplifier. The AD8502/AD8504 have a maximum offset voltage

of 3 mV and a typical input bias current of 1 pA operating rail-

to-rail on both the input and output. The AD8502/AD8504 can

operate from a single-supply voltage of +1.8 V to +5.5 V or a

dual-supply voltage of ±0.9 V to ±2.75 V.

With its low power consumption, low input bias current, and

rail-to-rail input and output, the AD8502/AD8504 are ideally

suited for a variety of battery-powered portable applications.

Potential applications include bedside monitors, pulse monitors,

glucose meters, smoke and fire detectors, vibration monitors,

and backup battery sensors.

The ability to swing rail-to-rail at both the input and output

helps maximize dynamic range and signal-to-noise ratio in

systems that operate at very low voltages. The low offset voltage

allows use of the AD8502/AD8504 in systems with high gain

without creating excessively large output offset errors. The

AD8502 and AD8504 offer an additional benefit by providing

high accuracy without the need for system calibration.

The AD8502/AD8504 are fully specified over the industrial

temperature range (−40°C to +85°C) and the extended indus-

trial temperature range (−40°C to +125°C). The AD8502 is

available in an 8-lead, SOT-23 surface-mount package. The

AD8504 is available in a 14-lead TSSOP surface-mount package.

Table 1. Low Supply Current Op Amps

Supply Current

1 μA

10 μA

20 μA

Single

AD8500

Dual

AD8502

ADA4505-2

AD8506

Quad

AD8504

ADA4505-4

AD8508