la4814v Sanyo Semiconductor Corporation, la4814v Datasheet - Page 6

• Manufacturer Part Number: la4814v
• Description: 2-channel Power Amplifier
• Manufacturer: Sanyo Semiconductor Corporation

5.Second amplifier control function (only when BTL mode is used)
6.Shorting between pins
7.Load shorting
8.Maximum rating
The second amplifier control function is a function to reduce the startup pop-noise in BTL mode. The pop noise can be
reduced by first turning on the IC while the second amplifier is stopped, then after the potential inside the IC gets
stabilized, turning on the second amplifier.
The values shown below are recommended for the control time.
a) When using microcomputer control
b) When microcomputer control is not possible
When power is applied with pins left short-circuited, electrical deterioration or damage may result.
Therefore, check before power application if pins are short-circuited with solder, etc. during mounting of IC.
If the load is left short-circuited for a long period of time, electrical deterioration or damage may occur.
Never allow the load to short-circuit.
When IC is used near the maximum rating, there is a possibility that the maximum rating may be exceeded even under
the smallest change of conditions, resulting in failure. Take sufficient margin for variation of supply voltage and use IC
within a range where the maximum rating will never be exceeded.
The second amplifier can be controlled by applying the following voltages to pin 9.
However, set the resistance value of the resistor R6 inserted in series in such a way that the condition in the following
formula is met.
The pin 9 injected current is expressed by the following formula :
When the microcomputer cannot be used, the second amplifier can be controlled by adding the external components
as shown in Fig. 4.
Second amplifier operation mode … V9 ≤ 0.3V
Second amplifier stop mode … V9 ≥ 1.6V
R6 ≤ 16.2 × (Vcnt - 1.6) kΩ
I9 = (57.6 × Vcnt - 31.7)/(1+0.058 × R6) μA
R7 (kΩ)
R9 (kΩ)
Twu [ms]
C8 (μF)
C5 [μF]
* Twu : Time after releasing standby to second amplifier turn-on
120
100
10
5
200
2.2
V CC (V)
100
3.6
6.8
68
250
3.3
100
6.8
56
3
LA4814V
300
4.7
V CC
500
10
+
Fig. 4
R7
C8
Vcnt
Fig. 3
R6
R5
R9
V9
9
14
9
8
CNT
V CC
CNT
STBY
No.A0972-6/17