NJU8754
- 4 -
Ver.2008-07-14
ABSOLUTE MAXIMUM RATINGS
(Ta=25°C)
PARAMETER SYMBOL RATING UNIT
Supply Voltage
V
DD
V
DDO
-0.3 to +5.5
-0.3 to +5.5
V
V
Input Voltage Vin -0.3 to V
DD
+0.3 V
Operating Temperature Topr -40 to +85 °C
Storage Temperature Tstg -40 to +125 °C
Power Dissipation P
D
360 (SSOP10)
620 (QFN20-M1)
mW
* : Mounted on two-layer board of based on the JEDEC.
Note 1) All voltage are relative to “V
SS
= 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
and V
DDO
-V
SS
should be connected for stable operation.
Note 4) Power Dissipation
The class-D amplifiers are more power efficient, and dissipate power less than general analog-amplifiers.
In theory, the NJU8754 actualize quite high output-power such as 1.2W at =5V operation with 8ohms load,
it looks as if the NJU8754 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(SSOP10) = 400°C/W
Power dissipation of the NJU8754 itself is calculated, as shown below.
Pd(W) = P
O
(W) X R
O
(Ω) / R
L
(Ω) + Pd
IC
(W)
Pd: Power Dissipation, PO: Output Power, RO: Internal Resistance(output driver)
RL: Load Resistance, Pd
IC:
Power of internal circuit
