LD511 DATA SHEET

Class A

Compression Amplifier

DESCRIPTION

The LD511 is a Class A compression amplifier which can

to 2.4 V. A voltage regulator, which is independent of supply

to the amplifier circuitry and to the microphone.

The LD511, in compression, has approximately 15 dB of

threshold adjustment by varying

R

TH

(see application circuit)

and a compression function ratio of

∞ : 1.

Minimum attack and release times are fixed at 7 ms and 40 ms

respectively and they can be adjusted simultaneously by

changing the filter capacitor on pin 8, although the ratio of

attack to release time is kept constant.

The output stage bias can be set to accommodate different

receiver impedances by changing the value of

R

E

. The

voltage across

R

E

(pin 2 to ground) is a constant 27 mV so the

bias current is 27 mV divided by the total value of

R

E

in parallel

with 500

Ω.

FEATURES

• 64 dB typical electrical gain

• 7 ms attack time, 40 ms release time

• 15 dB threshold adjustment

• low noise and distortion

• compression ratio

• 0.3 kHz - 6 kHz frequency response

STANDARD PACKAGING

• 10 pin MICROpac

• 10 pin MINIpac

• 10 pin PLID

®

• 10 pin SLT

• Chip (59 x 59 mils)

Au Bump

BLOCK DIAGRAM

VOLTAGE

REGULATOR

10K

35K

RECTIFIER

B OUT

AGC

GND

A IN

A OUT

B IN

VB

9

7

10

1

6

3

5

2

4

8

20K

- B

- A

500 - 32 - 11

All resistors in ohms, all capacitors

in farads unless otherwise stated

Revision Date: January 2001

GENNUM CORPORATION P.O. Box 489, Stn. A, Burlington, Ontario, Canada L7R 3Y3 tel. +1 (905) 632-2996

Web Site: www.gennum.com

E-mail: hipinfo@gennum.com