13

ICs for Audio Common Use

AN7191NZ

s Technical Information (continued)

[2] Application note (continued)

4. Ripple filter (continued)

6) After power off (STB-low), it takes about 10 seconds or less for the total circuit current to become the stand-

by current (10

µA or less). In order to reduce the inspection time at the set, insert the resistor of approx. 47 kΩ

between the ripple filter terminal and GND. This can shorten the time to reach the standby current.

5. GND terminal

1) Be sure to short-circuit each

GND terminal of pin 3, pin 8,

pin 9 and pin 14 at the outside

of the IC when use.

2) For each GND terminal, the one-

point earth, referenced to the

GND connection point of elec-

trolytic capacitor between the

supply terminal and GND, is

most effective for reducing the

distortion. Even in the worst case, ground pin 8, pin 9 of input GND separately from all the other GND

terminals.

3) Each GND terminal is not electrically short-circuited inside. Only pin 8 is connected with the substrate.

4) Pin 9 is input signal GND. Connect only pin 9 with Pre-GND.

6. Cooling fin

1) The radiation fin is not connected with GND terminal by using Au wire. Only pin 8 is electrically connected

through the substrate.

2) Always attach an outside heat sink to the cooling fin. The cooling fin must be fastened onto a chassis for use.

Otherwise, IC lead failure may occur.

3) Do not give the cooling fin any potential other than the GND potential. Otherwise, it may cause breakdown.

4) Connection of the cooling fin with GND can reduce the incoming noise hum. (It is not necessary to connect

with GND in use, but connect with the power GND when connect with GND.)

200

µA

33

µF

12

1.2 mA

20 k

Ω

3.5 k

Ω

Figure 4

3.5 k

Ω

20 k

Ω

30 k

Ω

Constant

current source

Protection

circuit

13

8

9

14

To GND of input

Figure 5

__ g