NJU8755
- 4 -
Ver.2003-03-12
! ABSOLUTE MAXIMUM RATINGS
(Ta=25°C)
PARAMETER SYMBOL RATING UNIT
Supply Voltage
V
DD
V
DDL
V
DDR
-0.3 ~ +5.5
-0.3 ~ +5.5
-0.3 ~ +5.5
V
V
V
Input Voltage Vin -0.3 ~ V
DD
+0.3 V
Operating Temperature Topr -40 ~ +85 °C
Storage Temperature Tstg -40 ~ +125 °C
Power Dissipation P
D
300 (SSOP20) mW
Note 1) All voltage are relative to “V
SS
= 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)) /θja
Pdmax: Maximum Power Dissipation, Tjmax: Junction Temperature = 125°C
Ta: Ambient Temperature, θja: Thermal Resistance of package(SSOP20) = 333°C/W
Power dissipation of the NJU8755 itself is calculated, as shown below.
Pd(W) = P
O
(W) X R
O
(Ω) / R
L
(Ω) + Pd
IC
(W)
Pd: Power Dissipation, P
O
: Output Power, R
O:
Internal Resistance(output driver)
R
L
: Load Resistance, Pd
IC:
Power of internal circuit
