TDA8780M

INTEGRATED CIRCUITS DATA SHEET TDA8780M True logarithmic amplifier Product specification Supersedes data of November 1994 File under Integrated Circuits, IC03 1995 Jul 25 Philips Semiconductors Product specification True logarithmic amplifier FEATURES 72 dB true logarithmic dynamic range Small-signal gain-adjustment facility Constant limiting output voltage Temperature and DC power supply voltage independent Easy interfacing to analog-to-digital converters Output DC level shift facility. APPLICATIONS Dynamic range compression IF signal dynamic range reduction in digital receivers Compression receivers. GENERAL DESCRIPTION The TDA8780M is a true logarithmic amplifier intended for dynamic range reduction of IF signals at 10.7 MHz in digital radio receivers. It offers true logarithmic characteristics over a 72 dB input dynamic range, has a small-signal gain-adjustment facility and a constant limiting output voltage for large input levels. QUICK REFERENCE DATA SYMBOL VP IP IP(PD) fin Vin(M) Tamb supply voltage supply current supply current in power-down mode operating input frequency dynamic logarithmic input voltage (peak value) operating ambient temperature PARAMETER − − − 0.06 −20 MIN. 4.5 5.0 − − − − − TYP. TDA8780M A unique feature is the smooth “changeover” from linear operation (inputs less than 60 µV) to logarithmic mode. The device is manufactured in an advanced BiCMOS process which enables high performance being obtained with low DC power supply con...