AS

“АLFA RPAR”

Joint Stock Company ALFA

Riga, Latvia www.alfarzpp.lv; alfa@alfarzpp.lv

2019 v.2

1

AS194

AS394

Matched NPN transistor pair

Features

• "Ideal" and identical transistors

• Common-mode rejection ratio

• Emitter-base offset voltage

150

мкВ

• Emitter-base offset voltage

temperature drift

1

мкВ /

• Current gain (h

0,96

• Parameters are guaranteed in

the range of collector current of

• Noise Voltage Density of

• Ideal logarithmic properties

> 120dB

<

100µV

0,1µV/

о

C

< 2%

10µА tо 1mА

1,8 nV /

Hz

AS194H,

AS394H,

AS394CH

AS194DE

AS394DE,

AS394CDE

General Description

The AS194 and AS394 are junction isolated ultra well-matched monolithic NPN transistor pairs with an

order of magnitude improvement in matching over conventional transistor pairs.

Electrical characteristics of these devices such as drift versus initial offset voltage, noise, and the

exponential relationship of base-emitter voltage to collector current closely approach those of a theoretical

transistor. Extrinsic base and emitter resistances is very low, giving very low noise and operating over a wide

current range.

To guarantee long term stability of matching parameters, internal clamp diodes have been added across

the emitter-base junction of each transistor. These prevent degradation due to reverse biased emitter current-

the most common cause of field failures in matched devices. The parasitic isolation junction formed by the

diodes also clamps the substrate region to the most negative emitter to ensure complete isolation between

devices.

The AS194H, AS394H, AS394CH are available in the 8-pin metal can TO5-8 package and the AS394DE

and AS394CDE in the 8-lead plastic SOIC-8 (150mil) EPAD package.

Connection Diagram

Pin Information

Top View

Pins number

Package type

Symbol

Description

8

C2

C1

B2

B1

E2

E1

2

3

1

8

7

4

5

6

C2

NC

B2

B1

E2

E1

2

3

1

8

7

4

5

6

C1

NC

TO5-8

SOIC-8/

EPAD

1

4

NC

Not connected

2

1

C1

Collector1

3

2

B1

Base1

4

3

E1

Emitter1

5

5

NC

Not connected

AS194H,

AS394H,

AS394CH

AS194DE

AS394DE,

AS394CDE

6

6

E2

Emitter2

7

7

B2

Base2

8

8

C2

Collector2

Metal Can Package

(ТО5-8)

SOIC-8 (150mil) / EPAD

EPAD

Isolated from

Substrate

Simplified schematics of AS194/394