HT82V7524 3W Mono Filter-free Class-D Audio Power Amplifier Features Description • 1.8V to 6V Single Supply The HT82V7524 is a filter-less mono Class D audio power amplifier IC. The device can deliver 3 watts into a 4Ω load at a 5V operating voltage or 5.1 watts into a 3Ω load at a 6V operating voltage. The advantage of using class D amplifiers is that they offer superior efficiency over the traditional linear amplifiers. This advantage results in less heat generation thus eliminating the need for heat sinking making them ideal for use in small outline products. • Output Power: ♦♦ 3W at 5V and 4Ω speaker ♦♦ 5.1W at 6V and 3Ω speaker • Up to 90% power efficiency • Automatic output power control – APC • 3.3mA quiescent current at 5V • Less than 0.2μA shutdown current One special feature of the device is its ability to operate over a wide voltage range, from 1.8V to 6V. Additional features include automatic power level control, wherein the output power remains consistent for different voltages. A function to reduce the annoying "pop" sound which could be generated during power on/off operations is also included. The device contains a range of protection features, such as output short circuit protection, over current/thermal shut off and auto recovery functions which restores the device to normal operation once the source of the problem has been resolved. • Pop noise elimination during power on/off • Shutdown function • Output pin short circuit protection with auto recovery • Over-temperature and over-current protection with auto recovery • Integrated hard limiter function • Limiter time and gain control on the fly • Differential 250kHz PWM allows Bridge-TiedLoad to increase output power and eliminate LC output filter • Differential signal processing for improved CMRR The superior efficiency of this Holtek class D audio amplifier together with its wide operating voltage and ability to directly drive speakers make it excellent for use in compact portable battery operated equipment where battery life will be an important consideration. Applications • Portable audio products • Battery powered audio products • MP3 players • Bluetooth speakers • Notebook/Tablet PCs • Smartphones Block Diagram Oscillator 20kΩ + - PWM - + 20kΩ Power Drive OUTP OUTN CAP INN VDD CTRL Rev. 1.00 Control Circuitry 1 VSS December 18, 2015 HT82V7524 Pin Assignment CTRL 1 CAP INN 2 INP 4 3 9 GND 8 OUTN 7 6 VSS VDD 5 OUTP HT82V7524 8 SOP-A Pin Description Pin Number Pin Name Type 1 CTRL AI Power down and LIM on/off control Description 2 CAP AO Capacitance for Limiter Operation 3 INN AI Negative input 4 INP AI Positive input 5 OUTP AO Positive output 6 VDD PWR Power supply 7 VSS PWR Ground 8 OUTN AO 9 GND PWR Negative output Exposed ground pad Legend: AO: Analog Output; AI: Analog Input; PWR: Power Pin Absolute Maximum Ratings Supply Voltage ..................................VSS-0.3V to 6.5V Input Voltage.............................VSS-0.3V to VDD+0.3V Storage Temperature ............................-50°C to 125°C Operating Temperature..…….................-40°C to 85°C Note: These are stress ratings only. Stresses exceeding the range specified under "Absolute Maximum Ratings" may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability. Rev. 1.00 2 December 18, 2015 HT82V7524 D.C. Characteristics Symbol VDD Parameter Supply Voltage VDD=2.5V~5.5V, TA=25°C, (unless otherwise noted) Test Conditions VDD Conditions — — 5V IQ Quiescent Current 3.6V No load 2V ISTB Standby Current Min. Typ. Max. Unit 1.8 — 6.0 V — 3.3 4 mA — 2.3 2.8 mA — 1.5 1.8 mA — VCTRL< 0.3V — 0.2 0.5 μA — ±25 — mV VOS Differential Output Offset Voltage — All inputs are AC grounded, AV=24 RDSON Static Drain-source On-state Resistance 5V RL=8Ω — 400 — mΩ RIN INN/INP Input Resistance — INN/INP to Ground — 20 — kΩ AV BTL Gain — V/V Ioc TAR Over-current Protection Threshold Over-current Detection Time (Time from overcurrent detected to retrial) Iq(oc) Supply Current Under Over-current Protection TA Operating Temperature 5V RL=8Ω — 24 — Vo+ shorted to VDD — 3 — Vo- shorted to VDD — 3 — Vo+ shorted to GND — 1.5 — Vo- shorted to GND — 1.5 — Vo+ shorted to Vo- — 1.8 — — 20 — ms — 2 — mA -40 — 85 °C Vo+/Vo- shorted to VDD/GND, Vo+ shorted to Vo- 5V — — A.C. Characteristics Symbol Parameter LIM THD (%) of Limiter Enable Point fSW Switching Frequency A VDD=2.5V~5.5V, TA=25°C, (unless otherwise noted) Test Conditions VDD Conditions Min. Typ. Max. Unit 3.6V~6.0V — — 1 — % — — 250 300 350 kHz dB PSRR Power Supply Rejection Ratio — — -70 — SNR Signal-to-noise Ratio 5V PO=1W, RL=8Ω — — 100 — dB CMRR Common Mode Rejection Ratio 5V VIC=1Vpp, RL=8Ω — -70 — dB Note: When supply voltage is below 2.2V and 4Ω speaker is used, the protection will be triggered if total harmonic distortion of the output is greater than 1%, To prevent this protection from happening an 8Ω speaker should be used instead. Rev. 1.00 3 December 18, 2015 HT82V7524 Operating Characteristics VDD=5V, Power Supply Capacitance=470μF, TA=25°C, (unless otherwise noted) Symbol Parameter Test Conditions VDD THD=1% 3.6V THD=10% THD=1% 5.0V THD=10% PO Output Power THD=1% 5.5V THD=10% THD=1% 6.0V THD=10% Rev. 1.00 Min. Typ. Max. 3Ω — 1.28 — 4Ω — 1.06 — 8Ω — 0.61 — 3Ω — 1.88 — 4Ω — 1.54 — 8Ω — 0.88 3Ω — 2.90 — 4Ω — 2.41 — 8Ω — 1.39 — 3Ω — 3.60 — 4Ω — 2.97 — 8Ω — 1.72 — 3Ω — 3.53 — 4Ω — 2.93 — 8Ω — 1.69 — 3Ω — 4.34 — 4Ω — 3.60 — 8Ω — 2.09 — 3Ω — 4.18 — 4Ω — 3.46 — 8Ω — 2.01 — Conditions 4 3Ω — 5.12 — 4Ω — 4.26 — 8Ω — 2.48 — Unit W December 18, 2015 HT82V7524 Typical Performance Characteristic Total Harmonic Distortion + Noise vs. Output Power Total Harmonic Distortion + Noise vs. Output Power VDD=3.6V @ 4Ω VDD=3.6V @ 8Ω Total Harmonic Distortion + Noise vs. Output Power Total Harmonic Distortion + Noise vs. Output Power VDD=5V @ 4Ω VDD=5V @ 8Ω Total Harmonic Distortion + Noise vs. Output Power Total Harmonic Distortion + Noise vs. Output Power VDD=5.5V @ 4Ω VDD=5.5V @ 8Ω Rev. 1.00 5 December 18, 2015 HT82V7524 4Ω, THD=10%, 1KHz 8Ω, THD=1%, 1KHz 4Ω , 10% 4Ω , 1% 2.5 8Ω , 10% 2 8Ω , 1% 1.5 1 0.5 0 3.6 5.0 5.5 3.6 6.0 5.0 4Ω, THD=1% & 10% 4Ω, THD=1%, 1KHz 8Ω, THD=1%, 1KHz 4Ω, THD=10%, 1KHz Po - Output Power - W 4Ω , 1% 3 2.5 2 8Ω , 1% 1.5 1 0.5 0 3.6 5.0 6.0 8Ω, THD=1% & 10% 4 3.5 5.5 VDD - V VDD - V Po - Output Power - W 8Ω, THD=10%, 1KHz 3 Po - Output Power - W Po - Output Power - W 4Ω, THD=1%, 1KHz 5 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 5.5 5 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 8Ω, THD=10%, 1KHz 4Ω , 10% 8Ω , 10% 3.6 6.0 5.0 5.5 6.0 VDD - V VDD - V 4Ω vs 8Ω, THD=1% 4Ω vs 8Ω, THD=10% Power Efficiency – 5V, 4Ω & 8Ω 4Ω + 33µH Efficiency (%) 8Ω + 33µH Po ‒ Output Power (W) Power Efficiency, 4Ω & 8Ω @5V Rev. 1.00 6 December 18, 2015 HT82V7524 Noise FFT - dBv Noise vs Frequency Frequency ‒ Hz Noise vs Frequency @5V Rev. 1.00 7 December 18, 2015 HT82V7524 Functional Description Low Voltage Detection The HT82V7524 is a Class D type Mono audio amplifier. Offering the advantages of fully digital operation this Class D audio amplifier has the advantages of low power losses resulting in higher efficiencies and reducing the need for heat sinking. Power down and Mute functions along with several protection features provide a highly functionally integrated audio amplifier solution. A power supply voltage monitoring circuit is integrated into the device. Should the supply voltage fall below a value of about 1.7V then the outputs will be disabled. When the supply voltage is maintained above 1.8V then the device will operate normally. Pop-Free The device includes a pop-free function. However to fully eliminate any annoying "pop" sounds being generated when the device is powered on or off, switching in the mute mode, switching in the shutdown mode, recovery from temperature protection or recovery from over-current protection it is important to ensure that the differential inputs are fully balanced. Amplifier Input Stage Looking into any of the audio pins will see a resistance of 20kΩ. The following diagram shows a typical input stage circuit. External Circuit C1 Rext1 Rin Automatic Output Power Control – APC 20K inp 0.1µF C2 1K Rext2 C3 The voltage gain of the amplifier will automatically adjust itself over supply voltage. This means that, regardless of changes to the supply voltage, the output power will remain at approximately the same level for a given input level. This feature could be important in battery powered applications where the supply voltage will drop as the batteries lose their charge. HT82V7524 4.7nF Rin 20K inn 0.1µF 1K Audio Input Stage Here external resistors have been connected between the amplifier audio inputs and the external audio signal source to setup the gain value. As the external signal needs to be ac coupled to the amplifier using capacitors this will form a high pass filter with these resistors. The –3db frequency of this input high pass filter will be given by. Shutdown Function The device can be shut down to conserve power during times when the audio output function of the product is not required. The shutdown function is executed when the voltage of the CTRL pin is below 0.3V. When the voltage of the CTRL pin is above 0.3V, the device will operate normally. f-3db=1/(2πRC) Hard Limiter and Control – LIM Where C is the ac coupling capacitance, C1 or C2, and R is the total resistance in series with the capacitor. So here C=0.1μF and R=Rin + Rext, in the example of the diagram which gives a value of 1kΩ + 20kΩ. Putting these numbers into the above equation gives a -3db frequency of about 76Hz. A bypass capacitor, C3, is also connected across the input pins to attenuate any high frequencies. This capacitor will form a low pass filter with the resistors. In this example, Rext=1kΩ, Rin=20kΩ and C=4.7nF. Thus the –3db frequency on the high frequency side is about 17.8kHz. The device includes a hard limiter function. The hard limiter detects the THD of the output signals and if it is below approximately 1% takes no action. However should the THD of the output signal be above 1% the hard limiter will immediately reduce the magnitude of the output signal by 6dB. This prevents the output signals from being clipped, avoiding the generation of high order harmonic signals which create unpleasant distorted sound effects. The hard limiter function is enabled when the CTRL pin voltage is within a range of 0.5 VDD~0.4VDD. When the CTRL pin voltage is above 0.9VDD the limiter will be disabled. When the limiter is disabled the amplifier will have a fixed gain as described elsewhere. Note that the limiter function will be in an unstable condition if the CTRL pin is within a range of 0.9 VDD ~ 0.5VDD. It is important to ensure that any external input pin related components are well matched. Not ensuring good matching of these differential input components may create an annoying pop noise during operation. Rev. 1.00 8 December 18, 2015 HT82V7524 Operating Mode LIM status Above 0.9VDD CTRL pin Setting Normal Off 0.9VDD ~ 0.5VDD Normal Unstable 0.5VDD ~ 0.4VDD Normal On Sleep — Below 0.3V EMI Output Filter Design To reduce EMI interference ferrite bead filters can be used. A ferrite filter will reduce EMI frequencies of around 1MHz and higher. Note that FCC and CE only test radiated emissions greater than 30MHz. When selecting a ferrite bead, choose one with a high impedance at high frequencies but with a low impedance at low frequencies. This audio signal magnitude reduction will be maintained for a certain period of time which is determined by the size of an external capacitor connected to the CAP pin. After this time period has elapsed the output audio signal will return to its normal magnitude. For a capacitor value of 0.22μF, the magnitude reduction time period is 8.5 seconds. This time period changes with the capacitor value in a linear manner. Therefore for a capacitor value of 0.1μF the time period will be 3.8 seconds. An internal current source is connected to the CAP pin which charges the external capacitor in a linear manner. Over Temperature Protection The device includes an integrated temperature sensor. When this detects an internal temperature about 120°C or above, the output signals will be disabled to protect the device from any damage. An automatic recovery circuit enables the device to return to normal operation when the internal temperature of the device returns to below around 100°C. Over Current Protection I A current detection circuit is integrated into the device to detect the switching current of the output stages of the device. It disables the device when the current is beyond the current limits specified in the operating characteristics. This protects the device when there is an accidental short circuit between the outputs or between the output pins and power/ ground pins. An automatic recovery circuit returns the device to normal operation when the problem source is removed. The delay time between protection and recovery is about 20ms. If the short circuit condition is not removed the after auto-recovery time the protection circuit will disable the output transistors again. The protection circuit will switch the output transistors on and off until the source of the short circuit condition is removed. HT82V7524 CAP External Capacitor CAP Pin Configuration An external control signal connected to the CAP pin can be used as a gain control signal as it can overwrite the limiter operation and behave like a gain control. If an external control signal is connected to the CAP pin, then when this signal is high, the amplifier will maintain its normal gain setting. However driving this pin low will force the amplifier to have a reduced gain down to 6dB from the original value. The voltage gain can be changed on the fly and there is no delay when the control signal switches in between the low and high values. Rev. 1.00 9 December 18, 2015 HT82V7524 Application Circuits Differential Input Configuration Differential Input Oscillator Ri INP 20K PWM Ri INN OUTP Power Drive OUTN 20K CAP VDD VDD R6 CTRL Control Circuitry Cs VSS C9 R7 Differential Input Application Differential Input Configuration with Input Capacitor Differential Input Oscillator Ri Ci INP 20K PWM Ci Ri INN OUTN 20K CAP VDD VDD R1 R2 OUTP Power Drive CTRL Control Circuitry C2 Cs VSS Differential Input Configuration with Input Capacitor Rev. 1.00 10 December 18, 2015 HT82V7524 Single-ended Input Configuration Single-ended Input Oscillator Ri Ci INP 20K PWM Ci Ri OUTP Power Drive OUTN 20K INN CAP VDD VDD R1 CTRL Control Circuitry Cs VSS C2 R2 Single-ended Input Configuration Development Circuit Board C4 1uF VDD C5 0.1uF C6 470uF + R6 C9 R7 L1 CTRL R1 100 C1 0.1uF J1 R2 100 R3 2k R4 1k Phone Jack C2 0.1uF R5 1k C3 4.7nF OUTN CAP VSS INN VDD INP OUTP C7 1nF bead L2 Speaker bead HT82V7524 C8 1nF With Band-pass Filter and Bead/Cap=1nF for EMI Suppression Rev. 1.00 11 December 18, 2015 HT82V7524 Package Information Note that the package information provided here is for consultation purposes only. As this information may be updated at regular intervals users are reminded to consult the Holtek website for the latest version of the package information. Additional supplementary information with regard to packaging is listed below. Click on the relevant section to be transferred to the relevant website page. • Further Package Information (include Outline Dimensions, Product Tape and Reel Specifications) • Packing Meterials Information • Carton information Rev. 1.00 12 December 18, 2015 HT82V7524 8-pin SOP (150mil) Outline Dimensions for Thermally Enhanced Variations Only (Exposed Pad) Symbol Dimensions in inch Min. Nom. Max. — A — 0.236 BSC B — 0.154 BSC — C 0.012 — 0.020 C′ — 0.193 BSC — D — — 0.069 D1 0.059 — — — E — 0.050 BSC E2 0.039 — — F 0.004 — 0.010 G 0.016 — 0.050 H 0.004 — 0.010 α 0° — 8° Symbol Rev. 1.00 Dimensions in mm Min. Nom. A — 6.0 BSC Max. — B — 3.9 BSC — 0.51 C 0.31 — C′ — 4.9 BSC — D — — 1.75 D1 1.50 — — E — 1.27 BSC — E2 1.00 — — F 0.10 — 0.25 G 0.40 — 1.27 H 0.10 — 0.25 α 0° — 8° 13 December 18, 2015 HT82V7524 Copyright© 2015 by HOLTEK SEMICONDUCTOR INC. The information appearing in this Data Sheet is believed to be accurate at the time of publication. However, Holtek assumes no responsibility arising from the use of the specifications described. The applications mentioned herein are used solely for the purpose of illustration and Holtek makes no warranty or representation that such applications will be suitable without further modification, nor recommends the use of its products for application that may present a risk to human life due to malfunction or otherwise. Holtek's products are not authorized for use as critical components in life support devices or systems. Holtek reserves the right to alter its products without prior notification. For the most up-to-date information, please visit our web site at http://www.holtek.com.tw. Rev. 1.00 14 December 18, 2015