LP502 GENNUM | Alldatasheet

Document overview

  • Manufacturer or author: Provided By ALLDATASHEET.COM(FREE DATASHEET DOWNLOAD SITE)
  • PDF pages: 4

Technical content

Patented 1985 Patent Pending Europe 83.300836.0 Canada 1183580 USA 4506169 Japan 58-06886 BLOCK DIAGRAM Low Distortion AGC Compression Amplifier LP502 CUSTOM DATA SHEET

  • adjustable gain from 0 to 60 dB
  • 0.94 V DC voltage regulator on-chip
  • attack time fixed at less than 1 ms
  • release time adjustable from 40 to 500 ms
  • low input referred noise 1.2 µV
  • <1 % distortion at 10 mVRMS output
  • operates from 1.05 to 3 VDC STANDARD PACKAGING
  • 8 pin MICROpac
  • 8 pin PLID
  • Chip (64 x 62 mils) Au Bump

FEATURES

GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. (905) 632-2996 fax: (905) 632-5946 Gennum Japan Corporation:C-101 Miyamae Villa ge, 2–10–42 Miyamae, Suginami–ku, Tokyo 168-0081, Japan tel. (03) 3334-7700 fax (03) 3247-8839 Document No. HP2802-1

DESCRIPTION

The LP502 is a compression (AGC) preamplifier that consists of a single-ended input inverting amplifier, with an internal current controlled resistance connected between input and output. By using R GT (see test circuit) to vary the value of this current controlled resistance, the amplifier gain and compression threshold can be controlled over a range of 60 dB. The AGC current is derived from a full wave rectifier driven by a differential amplifier. The attack time of the AGC circuit is fixed at less than 1 ms. The release time is adjustable from 40 to 500 ms by selecting the value of an external capacitor (C3). Internally, a series shunt voltage regulator produces a 0.94 V DC regulated output voltage. This provides a bias for electret microphones and permits circuit operations over a wide range of supply voltages, 1.05 to 3 V DC for LP502 without any degradation of electrical performances. As compared to the LD502, the LP502 incorporates an additional diode between the amplifier output and the AGC filter point. This “attack diode” is responsible for precharging the AGC filter point, which enables quicker attack time and helps to reduce the gain overshoot (during transients) that is observed in the LD502 with certain combinations of AGC input coupling and filter capacitors. However, with this diode connected, some level of AGC is always present with higher output levels even when the AGC input is disconnected. Therefore the LP502 cannot be used as a “pure” linear amplifier. GAIN SET A OUT AGC IN AGC FILTER GND A IN VREG VB VOLTAGE REGULATOR AMPLIFIER FULL WAVE RECTIFIER

Operating Temperature Range -10 °C to 50° C Storage Temperature Range -20 °C to 70° C CAUTION CLASS 1 ESD SENSITIVITY PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Gain A V VOUT = 11.0 mV, 38 41 46 dB Output Level V OHIGH VIN = 6.32 mV, S1 closed 7.5 12 15.5 mV Distortion -Linear THD V OUT = 11.0 mV - 1 2.9 % - AGC V IN = 6.32mV, S1 closed - 1 2.2 % Input Referred Noise IRN S2 closed,NFB 0.2 to 10 kHz at 12 dB/Oct - 1.2 2.2 µV Compression Function Ratio V IN = 0.1 to 6.32 mV, S1 closed 2 5 8 dB Total Amplifier Current IAMP 160 310 380 µA Regulated Voltage V REG 0.890 0.940 0.990 VDC Supply Rejection PSRR 51 60 - dB

ELECTRICAL CHARACTERISTICS

Conditions: Frequency = 1 kHz, Temperature = 25 °C, Supply Voltage V B = 1.3 VDC PIN CONNECTION 4 5 AGC FILTER AGC IN V B GND GAIN SET A OUT VREG

20 Log ( )VOUT

All parameters and switches remain as shown in Test Circuit unless otherwise stated in "Conditions" column Fig. 1 Test Circuit All resistors in ohms, all capacitors in microfarads unless otherwise stated A IN VOLTAGE REGULATOR AMP FULL WAVE RECTIFIER 1.0 RM 33K VIN RS= 3.5k 0.47 RGT 130k 1.0 0.1 S1 RL 10K VOUT VB= 1.3 VDC ITOT 8 5 RTH 1.0

3 HP2802-1

All resistors in ohms, all capacitors in microfarads unless otherwise stated Fig. 2 LP502/LC549Hearing Instrument Application All resistors in ohms, all capacitors in microfarads unless otherwise stated Fig. 3 LP502/LE507 Hearing Instrument Application 0.1 4.7 RS 3.9k FULL WAVE RECTIFIER 500k 0.1-1.0 0.1 4.7 VC 4.7 VB=1.3 VDC LP502 7 4 NC 0.047 RL=400 TYP 3 7 AMP LC5494 VOLTAGE REGULATOR 0.1 GAIN TRIM =10k 0.1 4.7 RS 3.9k 500k 0.47 0.1 0.1 0.1 BK1606 VB=1.3 VDC LP502 7 4 RE=33 VC 10k AMP 25k FULL WAVE RECTIFIER 18k 13.5k LE507 GAIN TRIM 33k VOLTAGE REGULATOR Z=1k

Fig. 8 Total Harmonic Distortion vs Output Level 4.0 3.0 2.0 1.0 0.0 OUTPUT (mV) THD (%) 100 0.01 0.1 1.0 10 INPUT (mV) Fig. 5 I/O Characteristics at Various RGT Values 0.1 RGT=130kΩ RGT=82kΩ RGT=47kΩ 100 0.01 0.1 1.0 10 INPUT (mV) Fig. 6 Effects of Supply Voltage Variation 0.1 VB=3 VDC VB=1.3 VDC Fig. 7 Frequency Response at Various CS Values OUTPUT (mV) 100 0.01 0.1 1.0 10 INPUT (mV) Fig. 4 I/O Characteristics at Various RTH Values RTH=0kΩ RTH=10kΩ RTH=22kΩ RTH=50kΩ -10 -12 -14 -16 -18 -20 CS=0.1 µF CS=0.22 µF CS=0.047 µF CS=0.033 µF 20 200 2K 20k FREQUENCY (Hz) RELATIVE OUTPUT (dB) OUTPUT (mV) OUTPUT (mV) RTH=0 Gennum Corporation assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement. © Copyright August 1997 Gennum Corporation. All rights reserved. Printed in Canada. DOCUMENT IDENTIFICATION PRODUCT PROPOSAL This data has been compiled for market investigation purposes only, and does not constitute an offer for sale. ADVANCE INFORMATION NOTE This product is in development phase and specifications are subject to change without notice. Gennum reserves the right to remove the product at any time. Listing the product does not constitute an offer for sale. PRELIMINARY DATA SHEET The product is in a preproduction phase and specifications are subject to change without notice. DATA SHEET The product is in production. Gennum reserves the right to make changes at any time to improve reliability, function or design, in order to provide the best product possible. RGT=68kΩ