LM4732 National Semiconductor, LM4732 Datasheet

no-image

LM4732

Manufacturer Part Number
LM4732
Description
Stereo 50W Audio Power Amplifier with Mute
Manufacturer
National Semiconductor
Datasheet

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LM4732A
Manufacturer:
ST/先科
Quantity:
20 000
Part Number:
LM4732TA
Manufacturer:
RCA
Quantity:
25
Part Number:
LM4732TA
Manufacturer:
NS/国半
Quantity:
20 000
© 2003 National Semiconductor Corporation
LM4732
Stereo 50W Audio Power Amplifier with Mute
General Description
The LM4732 is a stereo audio amplifier capable of typically
delivering 50W per channel of continuous average output
power into a 4Ω or 8Ω load with less than 10% THD+N from
20Hz - 20kHz.
The LM4732 has short circuit protection and a thermal shut
down feature that is activated when the die temperature
exceeds 150˚C. The LM4732 also has an under voltage lock
out feature for click and pop free power on and off.
Each amplifier of the LM4732 has an independent smooth
transition fade-in/out mute.
The LM4732 has a wide operating supply range from +/-10V
- +/-40V allowing for lower cost unregulated power supplies
to be used.
The LM4732 amplifiers can easily be configured for bridge or
parallel operation for 100W mono solutions.
Typical Application
FIGURE 1. Typical Audio Amplifier Application Circuit
DS200724
Key Specifications
Features
n Low external component count
n Quiet fade-in/out mute mode
n Wide supply range: 20V - 80V
Applications
n Audio amplifier for component stereo
n Audio amplifier for compact stereo
n Audio amplifier for self-powered speakers
n Audio amplifier for high-end and HD TVs
j
j
j
j
j
Output Power/Channel at 10% THD+N,
THD+N at 2 x 1W into 8Ω, 1kHz
Mute Attenuation
PSRR
Slew Rate
1kHz into 4Ω or 8Ω
20072422
www.national.com
19V/µs (typ)
110dB (typ)
0.01% (typ)
89dB (typ)
50W (typ)
July 2003

Related parts for LM4732

LM4732 Summary of contents

Page 1

... The LM4732 has a wide operating supply range from +/-10V - +/-40V allowing for lower cost unregulated power supplies to be used. The LM4732 amplifiers can easily be configured for bridge or parallel operation for 100W mono solutions. Typical Application FIGURE 1. Typical Audio Amplifier Application Circuit © ...

Page 2

... Connection Diagrams www.national.com Plastic Package (Note 13) 200724D7 Top View Order Number LM4732TA See NS Package Number TA27A TO-220 Top Marking 200724D6 Top View U - Wafer Fab Code Z - Assemble Plant Code XY - Date Code TT - Die Run Traceability L4732TA - LM4732TA 2 ...

Page 3

... IHF-A-Weighting Filter 600Ω (Input Referred -40˚C to +150˚C (Notes 1, 2) ≤ T −20˚C ≤ MAX A 20V ≤ TOTAL = 8Ω unless otherwise specified. L LM4732 Typical Limit (Note 6) (Notes 110 0.02 0. 105 170 ...

Page 4

... Note 14: CCIR/ARM: A Practical Noise Measurement Method; by Ray Dolby, David Robinson and Kenneth Gundry, AES Preprint No. 1353 (F-3). www.national.com (Notes 1, 2) (Continued) -T )/θ or the number given in the Absolute Maximum Ratings, whichever is lower. For the LM4732 (case to sink) is increased, but the heat sink will be electrically isolated from θ ...

Page 5

Bridged Amplifier Application Circuit FIGURE 2. Bridged Amplifier Application Circuit 5 20072414 www.national.com ...

Page 6

Parallel Amplifier Application Circuit www.national.com FIGURE 3. Parallel Amplifier Application Circuit 6 20072413 ...

Page 7

Single Supply Application Circuit FIGURE 4. Single Supply Amplifier Application Circuit Note: * Optional components dependent upon specific design requirements. Auxiliary Amplifier Application Circuit FIGURE 5. Special Audio Amplifier Application Circuit 20072406 200724D5 7 www.national.com ...

Page 8

External Components Description (Figures 1-5) Components 1 R Prevents current from entering the amplifier’s non-inverting input. This current may pass through to the load B during system power down, because of the amplifier’s low input impedance when the undervoltage circuitry ...

Page 9

Optional External Component Interaction The optional external components have specific desired functions. Their values are chosen to reduce the bandwidth and eliminate unwanted high frequency oscillation. They may, however, cause certain undesirable effects when they interact. Interaction may occur when ...

Page 10

Typical Performance Characteristics THD+N vs Output Power/Channel ± 22V 4Ω, 80kHz BW L Output Power/Channel vs Supply Voltage f = 1kHz 4Ω, 80kHz BW L Total Power Dissipation vs Output Power/Channel 1% THD (max ...

Page 11

Typical Performance Characteristics Crosstalk vs Frequency ± 22V 10W OUT R = 4Ω, 80kHz BW L Mute Attenuation vs Mute Pin Current P = 10W/Channel OUT THD+N vs Frequency ± 22V & 50W OUT Bridge ...

Page 12

Typical Performance Characteristics THD+N vs Output Power ± 22V, Bridge Mode (Note 16 8Ω, 80kHz BW L Output Power vs Supply Voltage, Bridge Mode (Note 16 1kHz 8Ω, 80kHz BW L Note 16: Bridge ...

Page 13

... For a longer turn-on mute time, a larger time constant, τ (sec), is needed. For the values M1 M show above and with the MUTE pins tied together, the LM4732 will enter play mode when the voltage at point A is -17.6V. The voltage at point A is found with Equation (1) below. -t/τ ...

Page 14

... SINGLE-SUPPLY AMPLIFIER APPLICATION The typical application of the LM4732 is a split supply am- plifier. But as shown in Figure 4, the LM4732 can also be used in a single power supply configuration. This involves using some external components to create a half-supply bias which is used as the reference for the inputs and outputs. ...

Page 15

... To achieve a transient free power-up and power-down, the voltage seen at the input terminals should be ideally the same. Such a signal will be common-mode in nature, and will be rejected by the LM4732. In Figure 4, the resistor R serves to keep the inputs at the same potential by limiting the voltage difference possible between the two nodes. This should significantly reduce any type of turn-on pop, due to an uneven charging of the amplifier inputs ...

Page 16

... It is advisable to keep the output compensation components and the 0.1µF supply decoupling capacitors as close as possible to the LM4732 to reduce the effects of PCB trace resistance and inductance. For the same reason, the ground return paths should be as short as possible. ...

Page 17

... It is hard for most power amplifiers to drive highly capacitive loads very effectively and normally results in oscillations or ringing on the square wave response. If the output of the LM4732 is connected directly to a capacitor with no series resistance, the square wave response will exhibit ringing if the capacitance is greater than about 0.2µF. If highly capaci- ...

Page 18

Application Information www.national.com (Continued) FIGURE 6. Inverting Amplifier Application Circuit 18 20072421 ...

Page 19

Application Information (Continued) FIGURE 7. Reference PCB Schematic 19 200724F9 www.national.com ...

Page 20

... Application Information LM4732 REFERENCE BOARD ARTWORK Composite Layer Top Layer www.national.com (Continued) 200724F6 200724F5 20 200724F7 Silk Layer 200724F8 Bottom Layer ...

Page 21

... Monolithic Ceramic 20% Electrolytic Radial / 50V 20% Electrolytic Radial / 50V SPDT (on-on) Switch Non-Switched PC Mount RCA PCB Banana Jack - BLACK PCB Banana Jack - RED 27 lead TO-220 Power Socket with push lever release or 21 Comment 1/4 Watt 1/4 Watt 1/4 Watt 1/4 Watt 1/4 Watt 1/4 Watt 1/4 Watt Jack LM4732 IC www.national.com ...

Page 22

... National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. inches (millimeters) Non-Isolated TO-220 27-Lead Package Order Number LM4732TA NS Package Number TA27A 2. A critical component is any component of a life ...

Related keywords