Low Voltage Compander
The MC33110 contains two variable gain circuits configured for
compressing and expanding the dynamic range of an audio signal. One
circuit is configured as an expander, while the other circuit can be configured
as a compressor or expander. Each circuit has a full wave rectifier to provide
average value information to a variable gain cell located in either the input
stage or the feedback path. An internal, temperature stable bandgap
reference provides the necessary precision voltages and currents required.
The MC33110 will operate from a supply voltage of 2.1 to 7.0 V, over a
temperature range of –40 to 85°C. The device is designed to accommodate
an 80 dB dynamic range from –60 dB to 20 dB, referenced to 100 mVrms.
Applications include cordless telephone, CB, walkie–talkie, most voice
RF links, and any application where the signal–to–noise ratio can be
improved by reducing the transmitted dynamic range. Other applications
include speakerphone and voice activated intercom, dictating machine,
standard telephone, etc.
The MC33110 is packaged in a 14 pin DIP for through–the–hole
applications and an SO–14 surface mount.
• Operating Supply Voltage: 2.1 to 7.0 V
• No Precision External Components Required
• 80 dB Dynamic Range Compressed to 40 dB, Re–expandable to 80 dB
• Unity Gain Level: 100 mVrms
• Adjustable Response Time
• Ambient Operating Temperature: –40 to 85°C
• Temperature Compensated Reference
• Applications Include Cordless Phone, CB Radio, Speakerphone, etc.
Order this document by MC33110/D
Simplified Block Diagram
10 k –
MOTOROLA RF/IF DEVICE DATA
9 20 k 1.0 µF
Exp Filter 3
Exp Output 4
Exp Input 5
12 Comp Filter
11 Comp Output
10 Comp Input
9 Inv Input
8 Comp Feedback
TA = –40 to 85°C
© Motorola, Inc. 1998