NTE7072
Integrated Circuit
Dual DC Controlled Potentiometer Circuit
Description:
The NTE7072 is a monolithic integrated circuit designed for use as a volume and tone control circuit
in stereo amplifiers. This dual tandem potentiometer IC consists of two ganged pairs of electronic
potentiometers with eight inputs connected via impedance converters, and the four outputs driving
individual operational amplifiers. The setting of each electronic potentiometer pair is controlled by
an individual DC control voltage. The potentiometers operate by current division between the arms
of cross鈥揷oupled long鈥搕ailed pairs. The current division factor is determined by the level and polarity
of the DC control voltage with respect to an externally available reference level of half the supply volt-
age. Since the electronic potentiometers are adjusted by a DC control voltage, each pair can be con-
trolled by single linear potentiometers which can be located in any position dictated by the equipment
styling. Since the input and feedback impedances around the operational amplifier gain blocks are
external, the NTE7072 can perform bass/treble and volume/loudness control. It also can be used as
a low鈥搇evel fader to control the sound distribution between the front and rear loudspeakers in car radio
installations.
Features:
D
High impedance inputs to both 鈥榚nds鈥?of each electronic potentiometer
D
Ganged potentiometers track within 0.5dB
D
Electronic rejection of supply ripple
D
Internally鈥揼enerated reference level available externally so that the control voltage can be
made to swing positively and negatively around a well鈥揹efined 0V level
D
The operational amplifiers have push鈥損ull outputs for wide voltage swing and low current
consumption
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The operation amplifier outputs are current limited to provide output short鈥揷ircuit protection
D
Although designed to operate from a 20V supply (giving a maximum input and output signal level
of 6V), the NTE7072 can work from a supply as low as 7.5V with reduced input and output signal
levels
Applications:
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Volume Control
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Tone Control
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Low Level Fader
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