LM4950TSBD National Semiconductor, LM4950TSBD Datasheet

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LM4950TSBD

Manufacturer Part Number
LM4950TSBD
Description
BOARD EVALUATION LM4950TS
Manufacturer
National Semiconductor
Series
Boomer®r
Datasheet

Specifications of LM4950TSBD

Amplifier Type
Class AB
Output Type
1-Channel (Mono) or 2-Channel (Stereo)
Max Output Power X Channels @ Load
7.5W x 1 @ 8 Ohm; 3.1W x 2 @ 4 Ohm
Voltage - Supply
9.6 V ~ 16 V
Operating Temperature
-40°C ~ 85°C
Board Type
Fully Populated
Utilized Ic / Part
LM4950
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
© 2004 National Semiconductor Corporation
LM4950
7.5W Mono-BTL or 3.1W Stereo Audio Power Amplifier
General Description
The LM4950 is a dual audio power amplifier primarily de-
signed for demanding applications in flat panel monitors and
TV’s. It is capable of delivering 3.1 watts per channel to a 4Ω
single-ended load with less than 1% THD+N or 7.5 watts
mono BTL to an 8Ω load, with less than 10% THD+N from a
12V
Boomer audio power amplifiers were designed specifically to
provide high quality output power with a minimal amount of
external components. The LM4950 does not require boot-
strap capacitors or snubber circuits. Therefore, it is ideally
suited for display applications requiring high power and mini-
mal size.
The LM4950 features a low-power consumption active-low
shutdown mode. Additionally, the LM4950 features an inter-
nal thermal shutdown protection mechanism along with short
circuit protection.
The LM4950 contains advanced pop & click circuitry that
eliminates noises which would otherwise occur during
turn-on and turn-off transitions.
The LM4950 is a unity-gain stable and can be configured by
external gain-setting resistors.
Typical Application
Boomer
DC
®
is a registered trademark of National Semiconductor Corporation.
power supply.
FIGURE 1. Typical Bridge-Tied-Load (BTL) Audio Amplifier Application Circuit
DS200470
Key Specifications
Features
n Pop & click circuitry eliminates noise during turn-on and
n Low current, active-low shutdown mode
n Low quiescent current
n Stereo 3.1W output, R
n Mono 7.5W BTL output, R
n Short circuit protection
n Unity-gain stable
n External gain configuration capability
Applications
n Flat Panel Monitors
n Flat panel TV’s
n Computer Sound Cards
j
j
j
j
turn-off transitions
Quiscent Power Supply Current
P
P
Shutdown current
OUT
V
OUT
V
DD
DD
(SE)
(BTL)
= 12V, R
= 12V, R
L
L
= 4Ω, 1% THD+N
= 8Ω, 10% THD+N
L
20047078
= 4Ω
L
= 8Ω
www.national.com
August 2004
16mA (typ)
3.1W (typ)
7.5W (typ)
40µA (typ)

Related parts for LM4950TSBD

LM4950TSBD Summary of contents

Page 1

... The LM4950 is a unity-gain stable and can be configured by external gain-setting resistors. Typical Application FIGURE 1. Typical Bridge-Tied-Load (BTL) Audio Amplifier Application Circuit Boomer ® registered trademark of National Semiconductor Corporation. © 2004 National Semiconductor Corporation Key Specifications j Quiscent Power Supply Current j P ...

Page 2

Connection Diagrams www.national.com Plastic Package, TO-263 Top View U = Wafer Fab Code Z = Assembly Plant Code XY = Date Code TT = Die Traceability Order Number LM4950TS See NS Package Number TS9A Plastic Package, TO-220 Top View U ...

Page 3

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (pin 6, referenced to GND, pins 4 and 5) Storage Temperature Input Voltage pins 3 and 7 pins and 9 Power Dissipation (Note 3) ESD Susceptibility (Note 4) ...

Page 4

Electrical Characteristics V Note 6: Typicals are measured at 25˚C and represent the parametric norm. Note 7: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level). Note 8: Datasheet min/max specification limits are guaranteed by design, test, or statistical ...

Page 5

Typical Performance Characteristics THD+N vs Frequency V = 12V 8Ω BTL operation, P OUT THD+N vs Frequency V = 12V 8Ω BTL operation, P OUT THD+N vs Frequency V = 12V, R ...

Page 6

Typical Performance Characteristics THD+N vs Frequency V = 12V 4Ω, SE operation both channels driven and loaded (average shown 1W, A OUT V THD+N vs Frequency V = 12V 8Ω, SE operation, ...

Page 7

Typical Performance Characteristics THD+N vs Output Power V = 12V 4Ω, SE operation both channels driven and loaded (average shown 1kHz IN THD+N vs Output Power V = 12V 16Ω, SE operation, ...

Page 8

Typical Performance Characteristics Output Power vs Power Supply Voltage R = 4Ω, SE operation, L both channels driven and loaded (average shown), at (from top to bottom at 12V): THD+N = 10%, THD Power Supply Rejection vs Frequency ...

Page 9

Typical Performance Characteristics Total Power Dissipation vs Load Dissipation V = 12V, BTL operation (from top to bottom at 3W 8Ω 16Ω Output Power vs Load Resistance V = 12V, BTL ...

Page 10

Typical Performance Characteristics THD+N vs Output Power V = 9.6V BTL operation THD+N vs Output Power V = 9.6V 8Ω, BTL operation BTLA = 20 1kHz V IN Total ...

Page 11

Typical Performance Characteristics Output Power vs Load Resistance V = 9.6V, BTL operation (from top to bottom at 15Ω): THD+N = 10%, THD Channel-to Channel Crosstalk vs Frequency V = 9.6V 4Ω, P ...

Page 12

Typical Performance Characteristics THD+N vs Output Power V = 15V operation both channels driven and loaded (average shown) Total Power Dissipation vs Load Dissipation per Channel V = 15V, SE operation ...

Page 13

Typical Performance Characteristics THD+N vs Output Power V = 16V 8Ω BTL operation 1kHz, BTLA IN Channel-to-Channel Crosstalk vs Frequency V = 16V 4Ω 1W, SE operation DD L OUT ...

Page 14

Typical Performance Characteristics Clipping Voltage vs Power Supply Voltage R = 8Ω, BTL operation (from top to bottom at 12V): positive signal swing, negative signal swing Clipping Voltage vs Power Supply Voltage R = 4Ω, SE operation, ...

Page 15

Application Information HIGH VOLTAGE BOOMER WITH INCREASED OUTPUT POWER Unlike previous 5V Boomer ® amplifiers, the LM4950 is de- signed to operate over a power supply voltages range of 9.6V to 16V. Operating on a 12V power supply, the LM4950 ...

Page 16

Application Information (2π Single Ended DMAX- The LM4950’s dissipation is twice the value given by Equa- tion (2) when driving two SE loads. For a 12V supply and two ...

Page 17

Application Information SELECTING EXTERNAL COMPONENTS Input Capacitor Value Selection Two quantities determine the value of the input coupling capacitor: the lowest audio frequency that requires amplifi- cation and desired output transient suppression. As shown in Figure 3, the input resistor ...

Page 18

Application Information FIGURE 4. Piezo-electric Transducer Capacitance ≤ 200nF AUDIO POWER AMPLIFIER DESIGN Audio Amplifier Design: Driving 4W into an 8Ω BTL The following are the desired operational parameters: Power Output Load Impedance Input Level Input Impedance Bandwidth 50Hz–20kHz The ...

Page 19

Application Information and 20kHz 100kHz L As mentioned in the SELECTING EXTERNAL COMPO- NENTS section, R and C create a highpass filter that INA INA sets the amplifier’s lower bandpass frequency limit. Find the ...

Page 20

Demonstration Board Layout www.national.com (Continued) FIGURE 6. Recommended TS SE PCB Layout: Top Layer FIGURE 7. Recommended TS SE PCB Layout: Bottom Layer 20 20047064 20047065 ...

Page 21

Demonstration Board Layout FIGURE 8. Recommended TS BTL PCB Layout: FIGURE 9. Recommended TS BTL PCB Layout: (Continued) 20047066 Top Silkscreen 20047067 Top Layer 21 www.national.com ...

Page 22

Demonstration Board Layout www.national.com (Continued) FIGURE 10. Recommended TS BTL PCB Layout: Bottom Layer 22 20047068 ...

Page 23

Physical Dimensions inches (millimeters) unless otherwise noted Order Number LM4950TS NS Package Number TS9A 23 www.national.com ...

Page 24

Physical Dimensions www.national.com inches (millimeters) unless otherwise noted (Continued) For Staggered Lead Non-Isolated Package Order Number LM4950TA NS Package Number TA09A 24 ...

Page 25

... BANNED SUBSTANCE COMPLIANCE National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2. ...

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