NJU8755

Note 1) All voltage are relative to "VS_S= V_SSL= V_SSR=0V" reference.
Note 2) The LSI must be used inside of the “Absolute maximum ratings”. Otherwise, a stress may cause permanent damage to the LSI.
Note 3) De-coupling capacitors for V_DD-V_SS, V_DDL-V_SSL , and V_DDR-V_SSR should be connected for stable operation.
Note 4) Power Dissipation
The class-D amplifiers are more power efficiency, and dissipate power less than general analog-amplifiers. In theory, the NJU8755 actualize quite high output-power such as 1.2W/channel at 5V operation with 8ohms load, and total power is supposed to be 2.4W. For this reason, it looks as if the NJU8755 exceeds the absolute maximum rating of the power dissipation. However, in practice, the effective output-power of usual music sound is only about 1/10 of its maximum output power, thus it may never exceed the absolute maximum rating.
The maximum power dissipation in the system is calculated, as shown below.
Pdmax(W) = (Tjmax(°C) - Ta(°C)) /ja
Pdmax: Maximum Power Dissipation, Tjmax: Junction Temperature = 125°C
Ta: Ambient Temperature, ja: Thermal Resistance of package(SSOP20) = 333°C/W
Power dissipation of the NJU8755 itself is calculated, as shown below.
Pd(W) = PO(W) X RO() / RL() + PdIC(W)
Pd: Power Dissipation, PO: Output Power, RO: Internal Resistance(output driver)
RL: Load Resistance, PdIC: Power of internal circuit

The NJU8755 is an analog signal input stereo class D power amplifier. The NJU8755 includes Inversion operational amplifier input circuit, PWM modulators, an output-short protector and a low voltage detector. The NJU8755 incorporates BTL amplifiers, which eliminate AC coupling capacitors, capable of driving up to 1.2W/channel with simple external LC low-pass filters.

Class-D operation achieves high power-efficiency,which achieves longer battery life for battery powered applications, thus the NJU8755 is suited for portable audio, note-PC, etc.