Instruction Manual

ManualsBrandsRainbow Electronics ManualsReceivers and AmplifiersMAX9758

General Description

The MAX9756/MAX9757/MAX9758 combine dual, 2.3W,

bridge tied load (BTL) stereo audio power amplifiers and

a DirectDrive

headphone amplifier in a single device.

These devices feature single-supply voltage operation,

shutdown mode, logic-selectable gain, a headphone

sense input, a 31-step analog volume control, and indus-

try-leading click-and-pop suppression. The headphone

amplifier uses Maxim’s patent-pending DirectDrive archi-

tecture that produces a ground-referenced output from a

single supply, eliminating the need for large DC-blocking

capacitors.

The MAX9756/MAX9757 feature automatic level control

(ALC) that automatically limits output power to the speak-

er in the event of an overpowered output.

The MAX9756/MAX9758s’ 150mA internal linear regula-

tor provides a complete solution for DAC- or CODEC-

based designs.

The MAX9756/MAX9757/MAX9758 are offered in space-

saving, thermally efficient 32-pin (5mm x 5mm x 0.8mm)

and 36-pin thin QFN (6mm x 6mm x 0.8mm) packages.

All devices are specified over the extended -40°C to

+85°C temperature range.

Features

♦ Automatic Level Control—Protects Speakers

♦ Analog Volume Control

♦ 120mW DirectDrive Headphone Amplifiers (16Ω)

♦ 150mA Adjustable LDO

♦ Class AB, 2.3W, Stereo BTL Speaker Amplifiers

(3Ω)

♦ High 95dB PSRR

♦ Low-Power Shutdown Mode

♦ Industry-Leading Click-and-Pop Suppression

♦ Short-Circuit and Thermal Protection

♦ Beep Input

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive

Headphone Amplifiers with Automatic Level Control

________________________________________________________________ Maxim Integrated Products 1

VOL

ALC

SINGLE SUPPLY 4.5V TO 5.5V

SINGLE SUPPLY 4.5V TO 5.5V SINGLE SUPPLY 4.5V TO 5.5V

1.2V TO 5V

HPS

BEEP

MAX9756

LDO

ALC

VOL

ALC

HPS

BEEP

MAX9757

ALC

VOL

1.2V TO 5V

HPS

BEEP

MAX9758

LDO

Simplified Block Diagrams

Ordering Information

Applications

PART

ALC

LDO PIN-PACKAGE

MAX9756ETX+

√√36 Thin QFN-EP**

MAX9757ETJ+*

√ — 32 Thin QFN-EP**

MAX9758ETJ+*

— √ 32 Thin QFN-EP**

19-3782; Rev 0; 8/05

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

Notebook PCs

Tablet PCs

Portable DVD

Players

Flat-Panel TVs

PC Displays

LCD Projectors

Portable Audio

Note: All devices specified for -40°C to +85°C operating

temperature range.

+Denotes lead-free package.

*Future product—contact factory for availability.

**EP = Exposed paddle.

Summary of content (31 pages)

PAGE 1
9-3782; Rev 0; 8/05 ON KIT EVALUATI AVAILABLE 2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control Features ♦ Automatic Level Control—Protects Speakers The MAX9756/MAX9757/MAX9758 combine dual, 2.3W, bridge tied load (BTL) stereo audio power amplifiers and a DirectDriveTM headphone amplifier in a single device.
PAGE 2
MAX9756/MAX9757/MAX9758 2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control ABSOLUTE MAXIMUM RATINGS Continuous Input Current (all other pins) .........................±20mA Continuous Power Dissipation (TA = +70°C, single-layer board) 32-Pin Thin QFN (derate 18.6mW/°C above +70°C).....1490mW 36-Pin Thin QFN (derate 20.4mW/°C above +70°C).....1633mW Continuous Power Dissipation (TA =+70°C, multilayer board) 32-Pin Thin QFN (derate 24.9mW/°C above +70°C).....
PAGE 3
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control (VDD = PVDD = HPVDD = CPVDD = IN = +5.0V, GND = PGND = CPGND = 0, SHDN = VDD, REGEN = VDD, DR = SET = GND, CBIAS = 1µF, CPVSS = 1µF, C1 = C2 = 1µF, PREF = unconnected, speaker loads terminated between OUT_+ and OUT_-, headphone load terminated between HP_ and GND, GAIN1 = GAIN2 = GAIN3 = VOL = 0 (AV(SP) = 15dB, AV(HP) = 0dB), TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 4
MAX9756/MAX9757/MAX9758 2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control ELECTRICAL CHARACTERISTICS (continued) (VDD = PVDD = HPVDD = CPVDD = IN = +5.
PAGE 5
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control (VDD = PVDD = HPVDD = CPVDD = IN = +5.0V, GND = PGND = CPGND = 0, SHDN = VDD, REGEN = VDD, DR = SET = GND, CBIAS = 1µF, CPVSS = 1µF, C1 = C2 = 1µF, PREF = unconnected, speaker loads terminated between OUT_+ and OUT_-, headphone load terminated between HP_ and GND, GAIN1 = GAIN2 = GAIN3 = VOL = 0 (AV(SP) = 15dB, AV(HP) = 0dB), TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 6
Typical Operating Characteristics (VDD = PVDD = HPVDD = CPVDD = IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, CBIAS = 1µF, CPVSS = 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.) VDD = 5V RL = 3Ω VDD = 5V RL = 4Ω OUTPUT POWER = 500mW 1 0.1 OUTPUT POWER = 500mW 0.1 OUTPUT POWER = 500mW 0.01 0.01 OUTPUT POWER = 1.8W OUTPUT POWER = 1.5W 0.001 OUTPUT POWER = 1W 0.
PAGE 7
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control (VDD = PVDD = HPVDD = CPVDD = IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, CBIAS = 1µF, CPVSS = 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.) CROSSTALK vs.
PAGE 8
Typical Operating Characteristics (continued) (VDD = PVDD = HPVDD = CPVDD = IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, CBIAS = 1µF, CPVSS = 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.) OUTPUT POWER vs. LOAD RESISTANCE TOTAL HARMONIC DISTORTION PLUS NOISE TOTAL HARMONIC DISTORTION PLUS NOISE (HEADPHONE MODE) vs. OUTPUT POWER (HEADPHONE MODE) vs.
PAGE 9
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control (VDD = PVDD = HPVDD = CPVDD = IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, CBIAS = 1µF, CPVSS = 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs.
PAGE 10
Typical Operating Characteristics (continued) (VDD = PVDD = HPVDD = CPVDD = IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, CBIAS = 1µF, CPVSS = 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.) CROSSTALK vs. FREQUENCY (LDO) LDO OUTPUT VOLTAGE ACCURACY vs. TEMPERATURE 3 DEVIATION (%) -30 -40 -50 -60 -70 IOUT = 50mA -90 1 0 -1 -3 0.
PAGE 11
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control (VDD = PVDD = HPVDD = CPVDD = IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, CBIAS = 1µF, CPVSS = 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.) OUTPUT NOISE vs. FREQUENCY (LDO) LINE-TRANSIENT RESPONSE MAX9756 toc42 MAX9756 toc41 110 COUT = 2μF 10Hz TO 100kHz 100 90 5.
PAGE 12
MAX9756/MAX9757/MAX9758 2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control Pin Description (continued) PIN NAME FUNCTION MAX9756 MAX9757 MAX9758 10 9 9 CPVDD 11 10 10 C1P 12 11 11 13 12 12 C1N 14 13 13 CPVSS 15 14 14 VSS 16 15 15 HPR Right Headphone Output 17 16 16 HPL Left Headphone Output 18 17 17 HPVDD Headphone Positive Power Supply. Bypass with 1µF ceramic capacitor to GND.
PAGE 13
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control The MAX9756/MAX9757/MAX9758 combine dual, 2W BTL stereo audio power amplifiers with a DirectDrive headphone amplifier in a single device. The stereo power amplifiers deliver up to 2.3W per channel into a 3Ω speaker from a 5V supply and the stereo headphone amplifiers deliver up to 130mW per channel into a 16Ω headphone from a 5V supply.
PAGE 14
MAX9756/MAX9757/MAX9758 2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control The MAX9756/MAX9757/MAX9758 feature an undervoltage lockout that prevents operation from an insufficient power supply and click-and-pop suppression that eliminates audible transients on startup and shutdown. The amplifiers include thermal-overload and short-circuit protection. An additional feature of the amplifiers is that there is no phase inversion from input to output.
PAGE 15
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control OUTPUT 2V/div Hold Time Hold time is the delay after the signal falls below the threshold level before the release phase is initiated. Hold time is internally set to 50ms and nonadjustable. The hold time is cancelled by any signal exceeding the set threshold level and attack is reinitiated.
PAGE 16
The release/attack time ratio that can be achieved by programming DR is listed in Table 2. OUTPUT POWER THRESHOLD vs. RPREF Table 2. Release to Attack Ratio 3.0 DR RELEASE/ATTACK RATIO VDD 200 VBIAS 633 GND 2000 OUTPUT POWER THRESHOLD (W) MAX9756/MAX9757/MAX9758 2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control 5V VDD 2.5 RL = 4Ω 2.0 1.5 RL = 8Ω 1.0 0.
PAGE 17
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control MAX9756 HPVDD VREF DAC VOL Figure 7. Volume Control Circuit Table 4. Volume Levels VVOL (V) = MULTIPLIER x SPEAKER MODE HEADPHONE MODE HPVDD GAIN (dB) GAIN (dB) MULTIPLIER 0.07 0.16 0.18 0.21 0.23 0.25 0.28 0.30 0.32 0.35 0.37 0.39 0.42 0.44 0.46 0.49 0.51 0.54 0.56 0.58 0.61 0.63 0.65 0.68 0.70 0.72 0.75 0.77 0.79 0.82 0.84 0.93 VVOL (MIN)* VVOL (MAX)* 0.00 0.49 0.57 0.64 0.72 0.80 0.88 0.95 1.
PAGE 18
Since the volume control (VOL) ADC is ratiometric to HPVDD, any variations in HPVDD are negated. The gain step sizes are not constant; the step sizes are 0.5dB/step at the upper extreme, 2dB/step in the midrange, and 4dB/step at the lower extreme. Figure 8 shows the transfer function of the volume control for a 3.3V supply. Low-Dropout Linear Regulator The MAX9756/MAX9758s’ low-dropout linear regulator (LDO) can be used to provide a clean power supply to a CODEC or other circuitry.
PAGE 19
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control Low-Frequency Response In addition to the cost and size disadvantages, the DCblocking capacitors limit the low-frequency response of the amplifier. The impedance of the headphone load to the DC-blocking capacitor forms a highpass filter with the -3dB point determined by: f − 3dB = 1 2πRLCOUT where R L is the impedance of the headphone and COUT is the value of the DC-blocking capacitor.
PAGE 20
MAX9756/MAX9757/MAX9758 2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control BIAS VOUT(BEEP) The MAX9756/MAX9757/MAX9758 feature an internally generated, power-supply independent, common-mode bias voltage of 2.5V referenced to GND. BIAS provides both click-and-pop suppression and sets the DC bias level for the amplifiers. Choose the value of the bypass capacitor as described in the BIAS Capacitor section. No external load should be applied to BIAS.
PAGE 21
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control Click-and-Pop Suppression Speaker Amplifier The MAX9756/MAX9757/MAX9758 speaker amplifiers feature Maxim’s comprehensive, industry-leading clickand-pop suppression. During startup, the click-andpop suppression circuitry eliminates any audible transient sources internal to the device. When entering shutdown, both amplifier outputs ramp to GND quickly and simultaneously.
PAGE 22
Output Power (Headphone Amplifier) The headphone amplifiers have been specified for the worst-case scenario—when both inputs are in phase. Under this condition, the drivers simultaneously draw current from the charge pump, leading to a slight loss in headroom of VSS. In typical stereo audio applications, the left and right signals have differences in both magnitude and phase, subsequently leading to an increase in the maximum attainable output power.
PAGE 23
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control Output Capacitor (C2) The output capacitor value and ESR directly affect the ripple at CPVSS. Increasing the value of C2 reduces output ripple. Likewise, decreasing the ESR of C2 reduces both ripple and output resistance. Lower capacitance values can be used in systems with low maximum output power levels. See the Output Power vs. Charge-Pump Capacitance graph in the Typical Operating Characteristics.
PAGE 24
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control MAX9756/MAX9757/MAX9758 MAX9756 Block Diagram 4.5V TO 5.5V 4.5V TO 5.5V 0.1μF 0.1μF 100μF PVDD VDD 32 9, 19 MAX9756 CIN 1μF 7 OUTL+ INL 1 LEFT-CHANNEL AUDIO INPUT GAIN/ VOLUME BTL AMPLIFIER 8 OUTL- DR 25 CT 35 PREF 29 0.
PAGE 25
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control 4.5V TO 5.5V 4.5V TO 5.5V 0.1μF 0.1μF 100μF PVDD VDD 29 8, 18 MAX9757 CIN 1μF 6 OUTL+ INL 32 LEFT-CHANNEL AUDIO INPUT GAIN/ VOLUME BTL AMPLIFIER 7 OUTL- DR 23 CT 30 PREF 27 100μF PEAK DETECT 180kΩ RIGHTCHANNEL AUDIO INPUT CIN 1μF INR 31 20 OUTR+ GAIN/ VOLUME CONTROL BTL AMPLIFIER 19 OUTR- BIAS 26 CBIAS 1μF 0V TO HPVDD VDD VOL 28 GAIN1 1 GAIN2 2 GAIN3 3 0.
PAGE 26
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control MAX9756/MAX9757/MAX9758 MAX9758 Block Diagram 4.5V TO 5.5V 4.5V TO 5.5V 0.1μF 0.1μF 100μF PVDD VDD 29 8, 18 MAX9758 CIN 1μF 6 OUTL+ INL 32 LEFT-CHANNEL AUDIO INPUT VOLUME BTL AMPLIFIER VOLUME BTL AMPLIFIER CIN 1μF RIGHT-CHANNEL AUDIO INPUT 7 OUTL- 20 OUTR+ INR 31 19 OUTR- BIAS 24 CBIAS 1μF 0V TO HPVDD VDD VOL 26 GAIN1 1 GAIN2 2 GAIN3 3 0.
PAGE 27
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control 4.5V TO 5.5V 3V TO 5.5V 10μF 1μF VDD PVDD HPVDD IN OUTL+ REGEN 1μF INL OUTL- MAX9756 1μF CODEC INR 1μF OUTR+ OUT OUTR- 1μF 47kΩ BEEP HPL SHDN HPS HPR GAIN1 μC GAIN2 GAIN3 HPVDD DR VOL 3V TO 5.5V CPVDD 1μF CPVSS C1P VSS C1N SET PREF CPGND 1μF 1μF BIAS 180kΩ BIAS CT 0.1μF 0.
PAGE 28
2.
PAGE 29
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control QFN THIN.EPS D2 D b CL 0.10 M C A B D2/2 D/2 k L MARKING AAAAA E/2 E2/2 CL (NE-1) X e E DETAIL A PIN # 1 I.D. e/2 E2 PIN # 1 I.D. 0.35x45° e (ND-1) X e DETAIL B e L1 L CL CL L L e e 0.10 C A C 0.08 C A1 A3 PACKAGE OUTLINE, 16, 20, 28, 32, 40L THIN QFN, 5x5x0.
PAGE 30
MAX9756/MAX9757/MAX9758 2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) COMMON DIMENSIONS EXPOSED PAD VARIATIONS PKG. 16L 5x5 20L 5x5 28L 5x5 32L 5x5 40L 5x5 SYMBOL MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX. MIN. NOM. MAX.
PAGE 31
2.3W Stereo Speaker Amplifiers and DirectDrive Headphone Amplifiers with Automatic Level Control QFN THIN.EPS (NE-1) X e E E/2 k D/2 CL (ND-1) X e D D2 D2/2 e b E2/2 L CL k E2 e L CL CL L1 L L e A1 A2 e A PACKAGE OUTLINE 36, 40, 48L THIN QFN, 6x6x0.8mm 21-0141 F 1 2 NOTES: 1. DIMENSIONING & TOLERANCING CONFORM TO ASME Y14.5M-1994. 2. ALL DIMENSIONS ARE IN MILLIMETERS. ANGLES ARE IN DEGREES. 3. N IS THE TOTAL NUMBER OF TERMINALS. 4.