Gennum Corporation LD512 Datasheet

Low Parts

Compression Amplifier

GB512/LD512 DATA SHEET

FEATURES

• 44 dB typical preamplifier gain

• 14 dB typical output stage gain

• compression function ratio 1:1 to 2:1 to

• automatic setting of transducer current

• operation down to 1.1 VDC

• greater than 40 dB volume control range

STANDARD PACKAGING

• 8 pin PLID

• 8 pin SLT (LD512)

• Chip (61 x 61 mils)

Au Bump

∞:1

DESCRIPTION

The GB512 and LD512 are 8 pin stand-alone input compression
amplifiers requiring minimal external parts. Each consists of a
voltage regulator for the electret microphone providing a high
power supply rejection ratio (PSRR), a compression stage
which has a 2:1 compression ratio, and an auto-biasing,
class A, voltage drive output stage.

The auto-bias output stage can drive a variety of impedances
ranging from 500 Ω to 5 kΩ without adding any external
resistors to set the bias.

The GB512 and LD512 are recommended for low to medium
gain/output ITE and ITC type hearing aids.

The GB512 is tested to tighter test limits.

V

REG

A IN

Revision Date: January 2001

4

3

V

V

REG

28 dB

A

-

CONTROL

2

C

AGC

B

5

200 mV

REF

16 dB

-

B

6

GND B OUT C IN

+

C

_

1

8

7

C OUT

BLOCK DIAGRAM

Document No. 500 - 75 - 08

GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. [phone] fax: [phone]

Japan Branch: A-302, Miyamae Village, 2-10-42, Miyamae, Suginami-ku, Tokyo 168, Japan tel. [phone] fax [phone]

ABSOLUTE MAXIMUM RATINGS

PIN CONNECTION

PARAMETER VALUE/UNITS

5

Supply Voltage 5 V DC

Power Dissipation 25mW
Operating Temperature Range -10°C to 40°C

Storage Temperature Range -20˚C to 70˚C

V

REG

A IN

C

AGC

B OUT

4

1

V

B

GND
C OUT

C IN

8

CAUTION

CLASS 1 ESD SENSITIVITY

ELECTRICAL CHARACTERISTICS

Conditions : Temperature 25˚C, Frequency 1 kHz, Supply Voltage 1.3 VDC.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX MIN TYP MAX UNITS

Amplifier Current I

Regulator Voltage V

Output Level V

Output Level V

Output Level V

Output Level V

AMP

REG

O1

O2

O3

O4

VIN = -88 dBV

VIN = -74 dBV

VIN = -54 dBV

VIN = -40 dBV

110

0.88

VO1 + 7

VO2 + 8

Input Referred Noise IRN NFB 0.2-10kHz at 12dB/oct

Total Harmonic Distortion THD VIN = -54 dBV

Receiver Bias Voltage V

Current Sinking Capability I

Release Time Factor T

Attack Time Factor T

All parameters and switches remain as shown in the Test Circuit unless stated in CONDITIONS column.

- actual voltage measured on the pin at given condition (X is pin number).

V

PX

BIAS

SINK

REL

ATT

Note 3

Note 4

100

GB512 LD512

290

0.98

-41

VO1 + 11

VO2+12

-18

3

4

300

-

-

-

110

0.88

-48

-

VO2 + 7

-23.5

-

-

160

3

-

-

-47

-23

200

0.93

-44

VO1 + 9

VO2+10

-20

-

-

1

2

200

3

-

-

8

100

5

200

0.93

-44

-

VO2+10

-20

1

2

200

8

100

5

290

0.98

-40

-

VO2+13

-17.5

3

4

240

-

-

-

µA

V

dBV

dB

dB

dBV

µV

%

mVDC

mA

ms/µF
ms/µF

DC

RMS

VO4
V

O/P

V

LEVEL

(dBV)

at PIN 1

V

500 - 75 - 08

Notes: 1. VO and Distortion measurements are taken

3

O

2

O

1

O

-88 dBV

-74 dBV

IN

IN

-54 dBV

-40 dBV

IN

IN

at pin 1.

2. Output stage gain = 20 log (R

A gain of 14 dB is recommended for

optimal stability. Stability is dependent

upon the ratio of the receiver impedance

) and the battery impedance to RF & RS.

(Z

L

/ RS) < (ZL/ RB)

(R

F

= VP5 - V

3. V

BIAS

4. Measured at pin 7

P7

/ RS).

F

2