National Semiconductor LME49810 Technical data

September 2007

LME49810 200V Audio Power Amplifier Driver with Baker Clamp

General Description

The LME49810 is a high fidelity audio power amplifier driver designed for demanding consumer and pro-audio applications. Amplifier output power may be scaled by changing the supply voltage and number of power transistors. The LME49810’s minimum output current is 50mA. When using a discrete output stage the LME49810 is capable of delivering in excess of 300 watts into a single-ended 8Ω load.

Unique to the LME49810 is an internal Baker Clamp. This clamp insures that the amplifier output does not saturate when over driven. The resultant “soft clipping” of high level audio signals suppresses undesirable audio artifacts generated when conventional solid state amplifiers are driven hard into clipping.

The LME49810 includes thermal shutdown circuitry that activates when the die temperature exceeds 150°C. The LME49810’s mute function, when activated, mutes the input drive signal and forces the amplifier output to a quiescent state.

Key Specifications

■ Wide operating voltage range ±20V to ±100V

■ Slew Rate 50V/μs (typ)

■ Output Drive Current 60mA (typ)

■ PSRR (f = DC) 110dB (typ)

■ THD+N (f = 1kHz) 0.0007 (typ)

Features

Very high voltage operation

■

Output clamp logic output

■

Thermal shutdown and mute

■

Customizable external compensation

■

Scalable output power

■

Applications

Guitar amplifiers

■

Powered studio monitors

■

Powered subwoofers

■

Pro audio

■

Audio video receivers

■

High voltage industrial applications

■

Boomer® is a registered trademark of National Semiconductor Corporation.

Tru-GND is a trademark of National Semiconductor Corporation.

Typical Application

LME49810

FIGURE 1. LME49810 Audio Amplifier Schematic

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Connection Diagram

LME49810

TB Package

Pin Descriptions

Pin Pin Name Description

1 ClpFlag Baker Clamp Clip Flag Output

2 Mute Mute Control

3 GND Device Ground

4 IN+ Non-Inverting Input

5 IN– Inverting Input

6 Comp External Compensation Connection

7 NC No Connect, Pin electrically isolated

8 Osense Output Sense

9 NC No Connect, Pin electrically isolated

10 –V

11 Bias

12 Bias

13 Sink Output Sink

14 Source Output Source

15 +V

Top View

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Order Number LME49810TB

See NS Package Number TB15A

N = National Logo

U = Fabrication plant code

Z = Assembly plant code

XY = 2 Digit date code

TT = Die traceability

TB = Package code

Negative Power Supply

Negative External Bias Control

Positive External Bias Control

Positive Power Supply

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LME49810

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FIGURE 2. LME49810 Simplified Schematic

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LME49810

Absolute Maximum Ratings (Notes 1, 2)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.

Supply Voltage |V+| + |V-|

200V

T Package (10 seconds) 260°C Storage Temperature –40°C to +150°C Thermal Resistance

73°C/W

4°C/W

Differential Input Voltage ±6V Common Mode Input Range 0.4VEE to 0.4V

Power Dissipation (Note 3) 4W ESD Susceptibility (Note 4) 1kV ESD Susceptibility (Note 5) 200V Junction Temperature (T

JMAX

) (Note 9)

150°C

Operating Ratings

Temperature Range

≤ TA ≤ T

MIN

Supply Voltage

MAX

−40°C ≤ TA ≤ +8 5°C

±20V ≤ V

SUPPLY

≤ ±100V

Soldering Information

Electrical Characteristics VCC = +100V, VEE = –100V (Notes 1, 2)

The following specifications apply for I 29dB.

Symbol Parameter Conditions

Quiescent Power Supply Current

THD+N Total Harmonic Distortion + Noise

NOISE

OUT

MUTE

Open Loop Gain

Output Voltage Swing

Output Noise

Output Current Current from Source to Sink Pins 60 50 mA (min)

Current into Mute Pin To activate the amplifier 100

SR Slew Rate

Input Offset Voltage VCM = 0V, IO= 0mA 1 3 mV (max)

Input Bias Current VCM = 0V, IO= 0mA 100 200 nA (max)

PSRR Power Supply Rejection Ratio f = DC, Input Referred 110 105 dB (min)

BIAS

CLIP

Baker Clamp Clipping Voltage

Baker Clamp Flag Output Voltage

Bias P&M Pin Open Voltage BiasP - BiasM 10

Bias Adjust Function Current 2.8

= 100μA, unless otherwise specified. Limits apply for TA = 25°C, CC = 10pF, and AV =

MUTE

LME49810

VCM = 0V, VO = 0V, IO = 0A

No Load, BW = 30kHz V

OUT

= 30V

, f = 1kHz

RMS

f = DC f = 1kHz, VIN = 1mV

RMS

THD+N = 0.05%, f = 1kHz

BW = 30kHz, A-weighted

Typical

(Note 6)

11 18 mA (max)

13 mA (max)

0.0007 % (max)

120

67.5

50 34 150

Limits

(Notes 7, 8)

200

VIN = 1V f = 10kHz square Wave

P-P

Clip Output Source pin Sink pin

= 4.7mA

FLAG

97.2

–96.4

0.4

95.5

–95.5

Units

(Limits)

dB dB

RMS

μV

μV (max)

μA (min)

μA (max)

V/μs(min)

V (max)

V (min)

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Note 1: All voltages are measured with respect to the GND pin unless otherwise specified.

Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is

functional but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guarantee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is given, however, the typical value is a good indication of device performance.

LME49810

Note 3: The maximum power dissipation must be derated at elevated temperatures and is dictated by T

allowable power dissipation is P C and the typical θJC is 4°C/W. Refer to the Thermal Considerations section for more information.

DMAX

= (T

- TA) / θJC or the number given in Absolute Maximum Ratings, whichever is lower. For the LME49810, T

JMAX

, θJC, and the ambient temperature, TA. The maximum

JMAX

Note 4: Human body model, 100pF discharged through a 1.5kΩ resistor.

Note 5: Machine Model, 220pF - 240pF discharged through all pins.

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 analysis.

Note 9: The maximum operating junction temperature is 150°C.

Note 10: Data taken with Bandwidth = 30kHz, AV = 29dB, CC = 10pF, and TA = 25°C except where specified.

JMAX

= 150°

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LME49810

FIGURE 3. LME49810 Test Circuit Schematic (DC Coupled)

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