LM1036MX - National Semiconductor

LM1036

LM1036 Dual DC Operated Tone/Volume/Balance Circuit

Literature Number: SNAS525B

February 25, 2008

LM1036

Dual DC Operated Tone/Volume/Balance Circuit

General Description

The LM1036 is a DC controlled tone (bass/treble), volume

and balance circuit for stereo applications in car radio, TV and

audio systems. An additional control input allows loudness

compensation to be simply effected.

Four control inputs provide control of the bass, treble, balance

and volume functions through application of DC voltages from

a remote control system or, alternatively, from four poten-

tiometers which may be biased from a zener regulated supply

provided on the circuit.

Each tone response is defined by a single capacitor chosen

to give the desired characteristic.

Features

■Wide supply voltage range, 9V to 16V

■Large volume control range, 75 dB typical

■Tone control, ±15 dB typical

■Channel separation, 75 dB typical

■Low distortion, 0.06% typical for an input level of 0.3 Vrms

■High signal to noise, 80 dB typical for an input level of 0.3

Vrms

■Few external components required

Block and Connection Diagram

Dual-In-Line (DIP) and Small Outline (SO) Package

514201

Order Number LM1036N, LM1036M or LM1036MX

See NS Package Number N20A or M20B

LM1036 Dual DC Operated Tone/Volume/Balance Circuit

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Supply Voltage 16V

Control Pin Voltage (Pins 4, 7, 9, 12, 14) VCC

Operating Temperature Range 0°C to +70°C

Storage Temperature Range −65°C to +150°C

Power Dissipation 1W

Lead Temp. (Soldering, 10 seconds) 260°C

Note 1: “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

VCC=12V, TA=25°C (unless otherwise stated)

Parameter Conditions Min Typ Max Units

Supply Voltage Range Pin 11 9 16 V

Supply Current 35 45 mA

Zener Regulated Output Pin 17

Voltage 5.4 V

Current 5 mA

Maximum Output Voltage Pins 8, 13; f=1 kHz

VCC=9V, Maximum Gain 0.8 Vrms

VCC=12V 0.8 1.0 Vrms

Maximum Input Voltage Pins 2, 19; f=1 kHz, VCC 2V 1.3 1.6 Vrms

Gain=−10 dB

Input Resistance Pins 2, 19; f=1 kHz 20 30 kΩ

Output Resistance Pins 8, 13; f=1 kHz 20 Ω

Maximum Gain V(Pin 12)=V(Pin 17); f=1 kHz −2 0 2 dB

Volume Control Range f=1 kHz 70 75 dB

Gain Tracking f=1 kHz

Channel 1–Channel 2 0 dB through −40 dB 1 3 dB

−40 dB through −60 dB 2 dB

Balance Control Range Pins 8, 13; f=1 kHz 1 dB

−26 −20 dB

Bass Control Range f=40 Hz, Cb=0.39 μF

(Note 3) V(Pin 14)=V(Pin 17) 12 15 18 dB

V(Pin 14)=0V −12 −15 −18 dB

Treble Control Range f= 16 kHz, Ct,=0.01 μF

(Note 3) V(Pin 4)=V(Pin 17) 12 15 18 dB

V(Pin 4)=0V −12 −15 −18 dB

Total Harmonic Distortion f=1 kHz, VIN=0.3 Vrms

Gain=0 dB 0.06 0.3 %

Gain=−30 dB 0.03 %

Channel Separation f=1 kHz, Maximum Gain 60 75 dB

Signal/Noise Ratio Unweighted 100 Hz–20 kHz 80 dB

Maximum Gain, 0 dB=0.3 Vrms

CCIR/ARM (Note 4)

Gain=0 dB, VIN=0.3 Vrms 75 79 dB

Gain=−20 dB, VIN=1.0 Vrms 72 dB

Output Noise Voltage at CCIR/ARM (Note 4) 10 16 μV

Minimum Gain

Supply Ripple Rejection 200 mVrms, 1 kHz Ripple 35 50 dB

Control Input Currents Pins 4, 7, 9, 12, 14 (V=0V) −0.6 −2.5 μA

Frequency Response −1 dB (Flat Response 250 kHz

20 Hz–16 kHz)

www.national.com 2

LM1036

Note 2: The maximum permissible input level is dependent on tone and volume settings. See Application Notes.

Note 3: The tone control range is defined by capacitors Cb and Ct. See Application Notes.

Note 4: Gaussian noise, measured over a period of 50 ms per channel, with a CCIR filter referenced to 2 kHz and an average-responding meter.

Typical Performance Characteristics

Volume Control

Characteristics

514220

Balance Control

Characteristic

514221

Tone Control Characteristic

514222

Tone Characteristic (Gain

vs Frequency)

514223

Tone Characteristic (Gain

vs Frequency)

514224

Loudness Compensated

Volume Characteristic

514225

3 www.national.com

LM1036

Input Signal Handling vs

Supply Voltage

514226

THD vs Gain

514227

Channel Separation vs

Frequency

514228

Loudness Control

Characteristic

514229

Output Noise Voltage

vs Gain

514230

THD vs Input Voltage

514231

www.national.com 4

LM1036

Application Notes

TONE RESPONSE

The maximum boost and cut can be optimized for individual

applications by selection of the appropriate values of Ct (tre-

ble) and Cb (bass).

The tone responses are defined by the relationships:

Where ab=at=0 for maximum bass and treble boost respec-

tively and ab=at=1 for maximum cut.

For the values of Cb and Ct of 0.39 μF and 0.01 μF as shown

in the Application Circuit, 15 dB of boost or cut is obtained at

40 Hz and 16 kHz.

ZENER VOLTAGE

A zener voltage (pin 17=5.4V) is provided which may be used

to bias the control potentiometers. Setting a DC level of one

half of the zener voltage on the control inputs, pins 4, 9, and

14, results in the balanced gain and flat response condition.

Typical spread on the zener voltage is ±100 mV and this must

be taken into account if control signals are used which are not

referenced to the zener voltage. If this is the case, then they

will need to be derived with similar accuracy.

LOUDNESS COMPENSATION

A simple loudness compensation may be effected by applying

a DC control voltage to pin 7. This operates on the tone control

stages to produce an additional boost limited by the maximum

boost defined by Cb and Ct. There is no loudness compen-

sation when pin 7 is connected to pin 17. Pin 7 can be

connected to pin 12 to give the loudness compensated vol-

ume characteristic as illustrated without the addition of further

external components. (Tone settings are for flat response,

Cb and Ct as given in Application Circuit.) Modification to the

loudness characteristic is possible by changing the capacitors

Cb and Ct for a different basic response or, by a resistor net-

work between pins 7 and 12 for a different threshold and

slope.

SIGNAL HANDLING

The volume control function of the LM1036 is carried out in

two stages, controlled by the DC voltage on pin 12, to improve

signal handling capability and provide a reduction of output

noise level at reduced gain. The first stage is before the tone

control processing and provides an initial 15 dB of gain re-

duction, so ensuring that the tone sections are not overdriven

by large input levels when operating with a low volume setting.

Any combination of tone and volume settings may be used

provided the output level does not exceed 1 Vrms, VCC=12V

(0.8 Vrms, VCC=9V). At reduced gain (<−6 dB)the input stage

will overload if the input level exceeds 1.6 Vrms, VCC=12V

(1.1 Vrms, VCC=9V). As there is volume control on the input

stages, the inputs may be operated with a lower overload

margin than would otherwise be acceptable, allowing a pos-

sible improvement in signal to noise ratio.

Application Circuit

514203

5 www.national.com

LM1036

Applications Information

OBTAINING MODIFIED RESPONSE CURVES

The LM1036 is a dual DC controlled bass, treble, balance and

volume integrated circuit ideal for stereo audio systems.

In the various applications where the LM1036 can be used,

there may be requirements for responses different to those of

the standard application circuit given in the data sheet. This

application section details some of the simple variations pos-

sible on the standard responses, to assist the choice of opti-

mum characteristics for particular applications.

TONE CONTROLS

Summarizing the relationship given in the data sheet, basi-

cally for an increase in the treble control range Ct must be

increased, and for increased bass range Cb must be reduced.

Figure 1 shows the typical tone response obtained in the

standard application circuit. (Ct=0.01 μF, Cb=0.39 μF). Re-

sponse curves are given for various amounts of boost and cut.

514204

FIGURE 1. Tone Characteristic (Gain vs Frequency)

Figure 2 and Figure 3 show the effect of changing the re-

sponse defining capacitors Ct and Cb to 2Ct, Cb/2 and 4Ct,

Cb/4 respectively, giving increased tone control ranges. The

values of the bypass capacitors may become significant and

affect the lower frequencies in the bass response curves.

514205

FIGURE 2. Tone Characteristic (Gain vs Frequency)

514206

FIGURE 3. Tone Characteristic (Gain vs Frequency)

Figure 4 shows the effect of changing Ct and Cb in the oppo-

site direction to Ct/2, 2Cb respectively giving reduced control

ranges. The various results corresponding to the different Ct

and Cb values may be mixed if it is required to give a particular

emphasis to, for example, the bass control. The particular

case with Cb/2, Ct is illustrated in Figure 5.

Restriction of Tone Control Action at High or Low

Frequencies

It may be desired in some applications to level off the tone

responses above or below certain frequencies for example to

reduce high frequence noise.

This may be achieved for the treble response by including a

resistor in series with Ct. The treble boost and cut will be 3 dB

less than the standard circuit when R=XC.

A similar effect may be obtained for the bass response by

reducing the value of the AC bypass capacitors on pins 5

(channel 1) and 16 (channel 2). The internal resistance at

these pins is 1.3 kΩ and the bass boost/cut will be approxi-

mately 3 dB less with XC at this value. An example of such

modified response curves is shown in Figure 6. The input

coupling capacitors may also modify the low frequency re-

sponse.

It will be seen from Figure 2 and Figure 3 that modifying Ct

and Cb for greater control range also has the effect of flatten-

ing the tone control extremes and this may be utilized, with or

without additional modification as outlined above, for the most

suitable tone control range and response shape.

Other Advantages of DC Controls

The DC controls make the addition of other features easy to

arrange. For example, the negative-going peaks of the output

amplifiers may be detected below a certain level, and used to

bias back the bass control from a high boost condition, to

prevent overloading the speaker with low frequency compo-

nents.

LOUDNESS CONTROL

The loudness control is achieved through control of the tone

sections by the voltage applied to pin 7; therefore, the tone

and loudness functions are not independent. There is nor-

mally 1 dB more bass than treble boost (40 Hz–16 kHz) with

loudness control in the standard circuit. If a greater difference

is desired, it is necessary to introduce an offset by means of

Ct or Cb or by changing the nominal control voltage ranges.

Figure 7 shows the typical loudness curves obtained in the

standard application circuit at various volume levels (Cb=0.39

μF).

www.national.com 6

LM1036

514207

FIGURE 4. Tone Characteristic (Gain vs Frequency)

514208

FIGURE 5. Tone Characteristic (Gain vs Frequency)

514209

FIGURE 6. Tone Characteristic (Gain vs Frequency)

514210

FIGURE 7. Loudness Compensated Volume

Characteristic

Figure 8 and Figure 9 illustrate the loudness characteristics

obtained with Cb changed to Cb/2 and Cb/4 respectively, Ct

being kept at the nominal 0.01 μF. These values naturally

modify the bass tone response as in Figure 2 and Figure 3.

With pins 7 (loudness) and 12 (volume) directly connected,

loudness control starts at typically −8 dB volume, with most

of the control action complete by −30 dB.

Figure 10 and Figure 11 show the effect of resistively offset-

ting the voltage applied to pin 7 towards the control reference

voltage (pin 17). Because the control inputs are high

impedance, this is easily done and high value resistors may

be used for minimal additional loading. It is possible to reduce

the rate of onset of control to extend the active range to

−50 dB volume control and below.

The control on pin 7 may also be divided down towards

ground bringing the control action on earlier. This is illustrated

in Figure 12, With a suitable level shifting network between

pins 12 and 7, the onset of loudness control and its rate of

change may be readily modified.

514211

FIGURE 8. Loudness Compensated Volume

Characteristic

514212

FIGURE 9. Loudness Compensated Volume

Characteristic

7 www.national.com

LM1036

514213

FIGURE 10. Loudness Compensated Volume

Characteristic

514214

FIGURE 11. Loudness Compensated Volume

Characteristic

514215

FIGURE 12. Loudness Compensated Volume

Characteristic

When adjusted for maximum boost in the usual application

circuit, the LM1036 cannot give additional boost from the

loudness control with reducing gain. If it is required, some

additional boost can be obtained by restricting the tone control

range and modifying Ct, Cb, to compensate. A circuit illustrat-

ing this for the case of bass boost is shown in Figure 13. The

resulting responses are given in Figure 14 showing the con-

tinuing loudness control action possible with bass boost pre-

viously applied.

USE OF THE LM1036 ABOVE AUDIO FREQUENCIES

The LM1036 has a basic response typically 1 dB down at 250

kHz (tone controls flat) and therefore by scaling Cb and Ct, it

is possible to arrange for operation over a wide frequency

range for possible use in wide band equalization applications.

As an example Figure 15 shows the responses obtained cen-

tered on 10 kHz with Cb=0.039 μF and Ct=0.001 μF.

www.national.com 8

LM1036

514216

FIGURE 13. Modified Application Circuit for Additional Bass Boost with Loudness Control

514217

FIGURE 14. Loudness Compensated Volume Characteristic

514218

FIGURE 15. Tone Characteristic (Gain vs Frequency)

9 www.national.com

LM1036

Simplified Schematic Diagram

(One Channel)

514219

*Connections reversed

www.national.com 10

LM1036

Physical Dimensions inches (millimeters) unless otherwise noted

Molded Dual-In-Line Package (N)

Order Number LM1036N

NS Package Number N20A

Small Outline (SO) Package

Order Number LM1036M or LM1036MX

NS Package Number M20B

11 www.national.com

LM1036

Notes

LM1036 Dual DC Operated Tone/Volume/Balance Circuit

For more National Semiconductor product information and proven design tools, visit the following Web sites at:

Products Design Support

Amplifiers www.national.com/amplifiers WEBENCH www.national.com/webench

Audio www.national.com/audio Analog University www.national.com/AU

Clock Conditioners www.national.com/timing App Notes www.national.com/appnotes

Data Converters www.national.com/adc Distributors www.national.com/contacts

Displays www.national.com/displays Green Compliance www.national.com/quality/green

Ethernet www.national.com/ethernet Packaging www.national.com/packaging

Interface www.national.com/interface Quality and Reliability www.national.com/quality

LVDS www.national.com/lvds Reference Designs www.national.com/refdesigns

Power Management www.national.com/power Feedback www.national.com/feedback

Switching Regulators www.national.com/switchers

LDOs www.national.com/ldo

LED Lighting www.national.com/led

PowerWise www.national.com/powerwise

Serial Digital Interface (SDI) www.national.com/sdi

Temperature Sensors www.national.com/tempsensors

Wireless (PLL/VCO) www.national.com/wireless

THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION

(“NATIONAL”) PRODUCTS. NATIONAL MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY

OR COMPLETENESS OF THE CONTENTS OF THIS PUBLICATION AND RESERVES THE RIGHT TO MAKE CHANGES TO

SPECIFICATIONS AND PRODUCT DESCRIPTIONS AT ANY TIME WITHOUT NOTICE. NO LICENSE, WHETHER EXPRESS,

IMPLIED, ARISING BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS

DOCUMENT.

TESTING AND OTHER QUALITY CONTROLS ARE USED TO THE EXTENT NATIONAL DEEMS NECESSARY TO SUPPORT

NATIONAL’S PRODUCT WARRANTY. EXCEPT WHERE MANDATED BY GOVERNMENT REQUIREMENTS, TESTING OF ALL

PARAMETERS OF EACH PRODUCT IS NOT NECESSARILY PERFORMED. NATIONAL ASSUMES NO LIABILITY FOR

APPLICATIONS ASSISTANCE OR BUYER PRODUCT DESIGN. BUYERS ARE RESPONSIBLE FOR THEIR PRODUCTS AND

APPLICATIONS USING NATIONAL COMPONENTS. PRIOR TO USING OR DISTRIBUTING ANY PRODUCTS THAT INCLUDE

NATIONAL COMPONENTS, BUYERS SHOULD PROVIDE ADEQUATE DESIGN, TESTING AND OPERATING SAFEGUARDS.

EXCEPT AS PROVIDED IN NATIONAL’S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, NATIONAL ASSUMES NO

LIABILITY WHATSOEVER, AND NATIONAL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY RELATING TO THE SALE

AND/OR USE OF NATIONAL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR

PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY

RIGHT.

LIFE SUPPORT POLICY

NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR

SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL

COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:

Life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and

whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected

to result in a significant injury to the user. A critical component is any component in a life support device or system whose failure to perform

can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness.

National Semiconductor and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other

brand or product names may be trademarks or registered trademarks of their respective holders.

For the most current product information visit us at www.national.com

National Semiconductor

Americas Technical

Support Center

Email:

new.feedback@nsc.com

Tel: 1-800-272-9959

National Semiconductor Europe

Technical Support Center

Email: europe.support@nsc.com

German Tel: +49 (0) 180 5010 771

English Tel: +44 (0) 870 850 4288

National Semiconductor Asia

Pacific Technical Support Center

Email: ap.support@nsc.com

National Semiconductor Japan

Technical Support Center

Email: jpn.feedback@nsc.com

www.national.com

IMPORTANT NOTICE

Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements,

and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should

obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are

sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.

TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard

warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where

mandated by government requirements, testing of all parameters of each product is not necessarily performed.

TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and

applications using TI components. To minimize the risks associated with customer products and applications, customers should provide

adequate design and operating safeguards.

TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right,

or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information

published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a

warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual

property of the third party, or a license from TI under the patents or other intellectual property of TI.

Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied

by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive

business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional

restrictions.

Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all

express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not

responsible or liable for any such statements.

TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably

be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing

such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and

acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products

and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be

provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in

such safety-critical applications.

TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are

specifically designated by TI as military-grade or "enhanced plastic."Only products designated by TI as military-grade meet military

specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at

the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use.

TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are

designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated

products in automotive applications, TI will not be responsible for any failure to meet such requirements.

Following are URLs where you can obtain information on other Texas Instruments products and application solutions:

Products Applications

Audio www.ti.com/audio Communications and Telecom www.ti.com/communications

Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers

Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps

DLP®Products www.dlp.com Energy and Lighting www.ti.com/energy

DSP dsp.ti.com Industrial www.ti.com/industrial

Clocks and Timers www.ti.com/clocks Medical www.ti.com/medical

Interface interface.ti.com Security www.ti.com/security

Logic logic.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense

Power Mgmt power.ti.com Transportation and Automotive www.ti.com/automotive

Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video

RFID www.ti-rfid.com

OMAP Mobile Processors www.ti.com/omap

Wireless Connectivity www.ti.com/wirelessconnectivity

TI E2E Community Home Page e2e.ti.com

Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265