Gennum Corporation LS505 Datasheet



High Gain Class A Amplifier

with Peak Clipping

LS505 DATA SHEET

FEATURES

• 72 dB typical gain

• 0.2 to 2.0 mA of transducer current adjustment

• 43 dB range of feedback volume control

• 1.0 to 1.6 V supply operating range

• Schottky diodes provide symmetrical peak clipping

• requires only 4 external parts for operation

STANDARD PACKAGING

• 8 pin MINIpac

• 8 pin MICROpac

• 8 pin PLID

®

• 8 pin SLT

• Chip (56 x 55 mils)

DESCRIPTION

The LS505 is a low voltage, monolithic integrated circuit
amplifier comprised of an operational amplifier driving a
single transistor Class A output stage with open collector.
Also included are a pair of complementary Schottky diodes
which provide the capability for symmetrical peak clipping in
a feedback configuration.

An internal negative feedback loop ensures a stable operating
point for the output stage over the designed operating voltage.
This also permits trimming of the output current with the use
of a single external resistor.

The input stage and microphone are biased by an internal

2.2 kΩ decoupling resistor to increase battery line signal
rejection.

V

MIC

8 1

I/P

6

100

R

VC

5

+

-

BLOCK DIAGRAM

All resistors in ohms, all capacitors in farads unless otherwise stated.

2.2k

GND

VB

4

7

33k

200

MPO

RE

O/P

3

2

Revision Date: January 1996

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

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

Document No. 500 - 20 - 11

ABSOLUTE MAXIMUM RATINGS

PIN CONNECTION

PARAMETER VALUE & UNITS

Supply Voltage 3 V

Power dissipation 25 mW
Operating Temperature -10 to +40 °C

O/P

MPO

V

4

B

R

E

1

R

5

VC

I/P

GND

V

8

MIC

Storage Temperature -20 to +70 °C

CAUTION

CLASS 1 ESD SENSITIVITY

ELECTRICAL CHARACTERISTICS

Conditions: Temperature 25 oC, Supply Voltage VB = 1.55 VDC

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS

Gain A
Temperature Coefficient of Gain η

Amplifier Current I
Temperature Coefficient of Current η

Transducer Current I

CL

A

AMP

Ι

TRANS

Total Harmonic Distortion THD VO = 0.707 VRMS -25 %

VO = 0.707 VRMS 68 72 76 dB

- 0.07 - dB/oC

180 210 280 µA

- -0.002 - mA/oC

1.3 1.5 1.9 mA

Input Referred Noise IRN NFB 0.2 to 10 kHz at 12 dB/oct - 1.2 2.0 µVRMS

Battery Resistance Stability RB = 22Ω --22 Ω

Volume Control Range RVC = 100 to 100.1 kΩ S1 open 36 43 - dB

Input Impedance (Pin 6) R

IN

-27- kΩ

Frequency Response (-3 dB) Low - 100 - Hz

High - 5K - Hz

Maximum Output S2 closed 0.125 0.19 0.275 VRMS
Gain Dependence of RB - 0.16 - dB/Ω

Emitter Bias Voltage (Pin 2) V

All switches and parameters remain as shown in test circuit unless stated in condition column

500 - 20 - 11

RE

2

- 42.5 - mV