–8–

REV. 0

AD8614/AD8644

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

5-Lead SOT-23

(RT Suffix)

0.1181 (3.00)

0.1102 (2.80)

PIN 1

0.0669 (1.70)

0.0590 (1.50)

0.1181 (3.00)

0.1024 (2.60)

1

3

4

5

0.0748 (1.90)

BSC

0.0374 (0.95) BSC

2

0.0079 (0.20)

0.0031 (0.08)

0.0217 (0.55)

0.0138 (0.35)

10

0

0.0197 (0.50)

0.0138 (0.35)

0.0059 (0.15)

0.0019 (0.05)

0.0512 (1.30)

0.0354 (0.90)

SEATING

PLANE

0.0571 (1.45)

0.0374 (0.95)

14-Lead TSSOP

(RU Suffix)

14

8

7

1

0.201 (5.10)

0.193 (4.90)

PIN 1

SEATING

PLANE

0.006 (0.15)

0.002 (0.05)

0.0118 (0.30)

0.0075 (0.19)

0.0256

(0.65)

BSC

0.0433

(1.10)

MAX

0.0079 (0.20)

0.0035 (0.090)

0.028 (0.70)

0.020 (0.50)

8

0

14-Lead Narrow SOIC

(R Suffix)

14

8

7

1

0.3444 (8.75)

0.3367 (8.55)

0.2440 (6.20)

0.2284 (5.80)

0.1574 (4.00)

0.1497 (3.80)

PIN 1

SEATING

PLANE

0.0098 (0.25)

0.0040 (0.10)

0.0192 (0.49)

0.0138 (0.35)

0.0688 (1.75)

0.0532 (1.35)

0.0500

(1.27)

BSC

0.0099 (0.25)

0.0075 (0.19)

0.0500 (1.27)

0.0160 (0.41)

8

0

0.0196 (0.50)

0.0099 (0.25)

x 45

The remaining two amplifiers can be used as low voltage

microphone preamplifiers. A single AD8614 can be used as a

stand-alone microphone preamplifier. Figure 29 shows this

implementation.

AD1881

(AC'97)

10k

21

MIC 1 IN

1k

1 F

2.2k

5V

10k

1k

1 F

2.2k

5V

MIC 1

MIC 2

22

MIC 2 IN

27

Figure 29. Microphone Preamplifier

SPICE Model Availability

The SPICE model for the AD8614/AD8644 amplifier is available

and can be downloaded from the Analog Devices’ web site at

http://www.analog.com. The macro-model accurately simulates

a number of AD8614/AD8644 parameters, including offset volt-

age, input common-mode range, and rail-to-rail output swing.

The output voltage versus output current characteristic of the

macro-model is identical to the actual AD8614/AD8644 perfor-

mance, which is a critical feature with a rail-to-rail amplifier model.

The model also accurately simulates many ac effects, such as gain

bandwidth product, phase margin, input voltage noise, CMRR and

PSRR versus frequency, and transient response. Its high degree of

model accuracy makes the AD8614/AD8644 macro-model one of

the most reliable and true-to-life models available for any amplifier.