la4500.pdf

Ordering number:ENN1164C

Monolithic Linear IC

LA4500

5.3W 2-Channel AF Power Amplifier

Features

• Low idling current (20mA/2 channels) enabling prolonged

battery life.

• Less dependence of idling current on V CC .

• High power (5.3W typ.

Package Dimensions

unit:mm

3037A-DIP20H

2).

• High ripple rejection (60dB at steady state).

Since filters are arranged in 3 stages (including 1 stage

inside the IC) to attain satisfactory ripple rejection at tran-

sient state, ripple occuring at the time of motor start can

be prevented from mixing in.

• Low pop noise at the time of power supply ON/OFF and

good starting balance between both channels (0.6s.) due

to built-in pop noise limiter.

• Pins provided for compensating high frequency responce.

• Low residual noise (0.4mV).

• Wide supply voltage range (6 to 24V) fascilitating design

of transformer power supply.

• Built-in thermal shutdown circuit,

• Designed so that inverse insertion or short between adja-

cent pins causes no destruction.

• Channel-to channel mirror image pin assignment and pro-

vision of Pre GND, Power GND pins enabling stable op-

eration and fascilitating artwork of printed circuit board.

• Minimum number of external parts required (9pcs. min.,

12pcs. typ.).

• Audio muting capability (for automatic music selection,

electronic tuner).

[LA4500]

R1.7

20.0

27.0

2.07

2.54

0.6

1.3

SANYO : DIP20H

Specifications

Absolute Maximum Ratings at Ta = 25˚C

V C

I O

–

˚C

–

Any and all SANYO products described or contained herein do not have specifications that can handle

applications that require extremely high levels of reliability, such as life-support systems, aircraft’s

control systems, or other applications whose failure can be reasonably expected to result in serious

physical and/or material damage. Consult with your SANYO representative nearest you before using

any SANYO products described or contained herein in such applications.

SANYO assumes no responsibility for equipment failures that result from using products at values that

exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges,or other

parameters) listed in products specifications of any and all SANYO products described or contained

herein.

SANYO Electric Co.,Ltd. Semiconductor Company

TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110-8534 JAPAN

21500TN (KT)/N2996RM/9036KI/8064KI No.1164–1/12

LA4500

Recommended Operating Conditions at Ta = 25˚C

V C

R L

Operating Characteristics at Ta = 25˚C, V CC =12V, R L =3

(stereo), f=1kHz, Rg=600

, See specified test circuit.

I C

P O

V O =

r i

k W

V N 1

V N 2

R r

Equivalent Circuit Block Diagram

No.1164–2/12

LA4500

Sample Application Circuit 1

No.1164–3/12

LA4500

Description of External Parts

C1 (C1)

Feedback capacitors

Related to low roll-off frequency f L for –3dB (100

F, f L =60Hz).

F is recommended. Increasing the capacitance value makes the

starting time (t s ) later. Decreasing the capacitance value makes the starting time (t s ) earlier.

F to 100

C3 (C4)

Bootstrap capacitors

Decreasing the capacitance value lowers output at low frequencies. A capacitance value of 47

F to

F is recommended.

C5 (C6) Oscillation blocking capacitors

Polyester film capacitor, being excellent in temperature characteristic, frequency characteristics, is

recommended.

C7 (C8) Output capacitors

Related to low roll-off frequency and output at low frequencies. BTL applications normally require

output capacitors.

C9 (C10) Switching distortion compensating capacitors

Compensates switching distortion which occurs at a high frequency of 10kHz. Ceramic capacitor of

0.01

100

F is recommended. If no problem arises in terms of radio-casette recorder design or tone, it is

unnecessary to use these capacitors.

C11

Filter capacitor (A)

Ripple filter circuit provided in power supply line. A capacitance value of 220

F is recommended.

F. The starting time and pop noise generated at the

time of power supply ON must be considered when fixing the capacitance value. A capacitance value of

100

F to 220

F is usable.

C12

Filter capacitor (B)

Ripple filter circuit provided in bias circuit. A capacitance value of 100

F is recommended. 3V suffices

the breakdown voltage of this capacitor. This capacitor is for ripple rejection at transient state and rejects

noise “buzz” generated when the above-mentioned filter circuit provided in power supply line is satu-

rated due to large ripple and supply voltage drop induced at the time of start of the motor connected to

power supply line. If the motor is satisfactory in performance and the power supply regulation including

ripple is 500mVrms or less, it is unnecessary to use this capacitor. If noise “buzz” is not offensive to the

ear, it is unnecessary to use this capacitor. In this case, other basic performances are not affected ad-

versely.

Feaures of IC Contents and Functions of Other Pins

(a) Since the input circuit uses PNP transistors and the bias voltage is set nearly equal to 0, no input coupling

capacitor is required, thereby enabling direct coupling. However, if slider contact noise of the variable resistor

presents any problem, connect a capacitor in series with input.

(b) Various ideas embodied in the idling circuit enable reduced I CCO and prolonged battery life. Since the non-

operating level of the idling circuit is made equal to that of the amplifier, crossover distortion does not worsen at

the time of reduced voltage.

tion. Radiation to the radio-frequency stage is made less by soft clipping.

(d) Capacitors for oscillation compensation are contained as a means of reducing the number of external parts.

10pF

2 and 2pF

2 are used. Hig roll-off frequency f H (–3dB point) depends on these capacitance values.

(f H =28kHz)

(e) A thermal shutdown (THD) circuit is contained to prevent the IC from being destroyed by abromal heat genera-

tion attributable to insufficient heat dissipation. Pin (11) is used as THD control pin. Biasing pin (11) externally

makes the operating temperature lower ; and connecting a resister across pin (11) and (10) makes the operating

temperature higher. If pin (11) is connected to GND, the thermal shutdown circuit stops operating.

(f) The pin assignment is carefully considered so that no destruction takes place even if power supply is applied at a

state where adjacent pins are shorted by solder bridge, etc. Even 180

C-rotated insertion causes no destruction.

(g) Collector pins (5), (16) and base pins (6), (15) for predrive can be conveniently used in applications. For oscilla-

tion compensation occuring when operated at a lowered gain, connect a capacitor across the pins (4) and (6) and

a capacitor across pins (15) and (16). For fH compensation occuring when operated at a lowered gain, connect a

capacitor across pins (4) and (6) and a capacitor across pins (17) and (15). Further soft clippling and prevention

of waveform distortion at high frequencies are attained by connecting a series circuit of diode (DS442) and

resistor (10k

) across pin (6) and GND and the same across pin (15) and GND.

Continued on next page.

No.1164–4/12

A capacitance value of 47

Ripple rejection SVRR starts to be saturated at 47

LA4500

Continued from preceding page.

(h) Feedback resistance R NF is contained and the voltage gain is fixed at 50dB so that the variations in the voltage

gain can be minimized. The gain can be lowered by connecting R NF externally.

(i) Biasing pin (12) as shown below causes DC audio muting to be applied, thereby cutting off the IC. This makes

attack time, recovery time, pop noise, etc. saticefactory.

It is recommended that the following method be used to control the NF pin.

No.1164–5/12

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