Datasheet TDA7056A (NXP) - 4

NXP Semiconductors Product specificiation 3 W BTL mono audio output amplifier with TDA7056A DC volume control
FUNCTIONAL DESCRIPTION
Thus, a reduced power supply and smaller capacitors can be used which results in cost savings. The TDA7056A is a mono BTL output amplifier with DC volume control, designed for use in TV and monitor but For portable applications there is a trend to decrease the also suitable for battery-fed portable recorders and radios. supply voltage, resulting in a reduction of output power at conventional output stages. Using the BTL principle In conventional DC volume circuits the control or input increases the output power. stage is AC coupled to the output stage via external capacitor to keep the offset voltage low. The maximum gain of the amplifier is fixed at 35.5 dB. The DC volume control stage has a logarithmic control In the TDA7056A the DC volume stage is integrated into characteristic. the input stage so that coupling capacitors are not required and a low offset voltage is maintained. The total gain can be controlled from 35.5 dB to −44 dB. At the same time the minimum supply voltage remains low. If the DC volume control voltage is below 0.3 V, the device switches to the mute mode. The BTL principle offers the following advantages: • lower peak value of the supply current The amplifier is short-circuit proof to ground, VP and across the load. A thermal protection circuit is also • the frequency of the ripple on the supply voltage is twice implemented. If the crystal temperature rises above the signal frequency +150 °C the gain will be reduced, thereby reducing the output power. Special attention is given to switch-on and off clicks, low HF radiation and a good overall stability.
LIMITING VALUES
In accordance with the Absolute Maximum System (IEC 134).
SYMBOL PARAMETER CONDITIONS MIN. MAX. UNIT
VP supply voltage range − 18 V IORM repetitive peak output current − 1.25 A IOSM non repetitive peak output current − 1.5 A P < tot total power dissipation Tcase 60 °C − 9 W Tamb operating ambient temperature range −40 +85 °C Tstg storage temperature range −55 +150 °C Tvj virtual junction temperature − +150 °C Tsc short-circuit time − 1 hr V3 input voltage pin 3 − 8 V V5 input voltage pin 5 − 8 V
THERMAL RESISTANCE SYMBOL PARAMETER THERMAL RESISTANCE
Rth j-a from junction to ambient in free air 55 K/W Rth j-c from junction to case 10 K/W
Note to the thermal resistance
VP = 12 V; RL = 16 Ω; The maximum sine-wave dissipation is = 1.8 W. The Rth vj-a of the package is 55 K/W; Tamb (max) = 150 − 55 x 1.8 = 51 °C July 1994 4 Document Outline Features General description Missing Current Limiter (MCL) Quick reference data Ordering information Pinning Functional description Limiting values Thermal resistance Characteristics Application information Package outline Soldering Introduction Soldering by dipping or by wave Repairing soldered joints Data sheet status Disclaimers