General Description Key Specifications The AUD4990 is an audio power amplifier essentially designed for mobile phones and other portable communication devices. It can deliver 1.3 watts of continuous average power to an 8 Ohm BTL load and 2 watts of continuous average power to a 4 Ohm BTL load. There is less than 1% distortion from a 5V DC power supply. Wide Power Supply Voltage Range Typical THD at 1W, 8Ω High PSRR Low Quiescent Current 2.7V < VDD < 5.5 0.2% (typ) 68 dB (typ) 2.5 mA (typ) Features The AUD4990 were specifically designed to provide high quality output power with a minimal amount of external components. It requires no output coupling capacitors, for this reason, it is perfectly meet the needs of mobile phone and other low voltage applications where require the consumption of power in the smallest amount. Space Saving Thermal Package Active High or Low Shutdown Mode External Gain Configuration Unity-gain stable Can drive CL up to 200pF Application The AUD4990 can offer a low standby current and a zero shutdown current. Furthermore, the wake up time of the amplifier is fast enough to use shutdown mode as a mute function. Mobile Phones PDAs Notebook Computers Portable electronic devices The AUD4990 has an advanced pop & click circuitry that eliminates the noise during turning on and turning off of the device. Typical Application VDD + CS 1.0µF RF 20kΩ Audio Input Ri 20kΩ - IN + IN Ci 0.39µF _ VO1 - + 20kΩ 20kΩ Bypass + CB 1.0µF Shutdown Shutdown Mode GND GND V DD V DD Control ShutDown 0 1 0 1 BIAS _ V DD/2 RL 8Ω VO2 + + ShutDown Status Shutdown On On Shutdown SD Mode GND Figure 1 Audio Power Amplifier with AV = 2 http://www.analogexpress.com Figure 2 THD + N vs Output Power 1 V1.45 2 Watt Audio Power Amplifier with Selectable Shutdown AUD4990 2 Watt Audio Power Amplifier with Selectable Shutdown AUD4990 January 2007 AUD4990 Pin Assignment 2 Watt Audio Power Amplifier with Selectable Shutdown AUD4990D10-3 (Bottom View) V1.45 AUD4990D10-4 (Bottom View) Pin No. Pin Name Type Description 1 SD I Shutdown selection pin 2 BYPASS I Common mode voltage 3 SD MODE I Shutdown Mode selection pin 4 + IN I Positive differential input 5 - IN I Negative differential input 6 VO1 O Negative BTL Output 7 -- -- NC pin 8 VDD I Power supply 9 GND I Ground 10 VO2 O Positive BTL Output 2 http://www.analogexpress.com 8 2 7 3 6 4 5 2 Watt Audio Power Amplifier with Selectable Shutdown 1 AUD4990 Pin Assignment (continuous) AUD4990MS08 (Top View) Pin No. Pin Name Type Description 1 SD I Shutdown selection pin 2 BYPASS I Common mode voltage 3 + IN I Positive differential input 4 - IN I Negative differential input 5 VO1 O Negative BTL Output 6 VDD I Power supply 7 GND I Ground 8 VO2 O Positive BTL Output *SD MODE pin shorted to GND in the MSOP8 package Operation Conditions Parameter Symbol Min Power Supply Voltage VDD Operating Temperature Range TA Typ Max Unit 2.7 5.5 V -40 85 °C Ordering Information + Part Number Package Marking AUD4990D10-3 10-lead DFN 3x3 A4990D WXYZ AUD4990D10-4 10-lead DFN 4x3 A4990D WXYZ AUD4990MS08 8-lead MSOP8 A4990M WXYZ + WXYZ = assembly and date code http://www.analogexpress.com 3 V1.45 AUD4990 Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the Analog Express Sales Office/Distributors for availability and specifications. 2 Watt Audio Power Amplifier with Selectable Shutdown Supply Voltage Storage Temperature Input Voltage Power Dissipation ESD Susceptibility Junction Temperature 6.0V -65°C to +150°C -0.3V to VDD + 0.3V Internally Limited HBM 2000V 150°C Thermal Resistance θJC (DFN10 4x3) θJA (DFN10 4x3) θJC (DFN10 3x3) θJA (DFN10 3x3) 63°C/W 12°C/W 55°C/W 10°C/W Electrical Characteristics, VDD = 5V The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA = 25°C. AUD4990 Symbol Parameter Conditions IDD Quiescent Power Supply Current ISD Shutdown Current VOS Output Offset Voltage ROUT Resistor Output to GND PO Units (Limits) Typical Limit VIN = 0V, IO = 0A, No Load 2.5 7.5 mA (max) VIN = 0V, IO = 0A, 8Ω Load 3.5 9 mA (max) VSD = VSD Mode 0.1 2.0 µA (max) 25 mV (max) 9.7 kΩ (max) 7.0 kΩ (min) 8.5 Output Power (8Ω) THD+N = 10% (max); f = 1kHz 1.3 W (4Ω) THD+N = 10% (max); f = 1kHz 2 W TWU Wake-up time 300 ms THD+N Total Harmonic Distortion+Noise PO = 0.5W; f = 1kHz 0.2 % PSRR Power Supply Rejection Ratio VRIPPLE = 200mV sine p-p Input terminated with 10Ω 52 (217Hz) 68 (1kHz) dB Efficiency η VDD = 5.0V, PO = 1W 63% Electrical Characteristics, VDD = 3V The following specifications apply for the circuit shown in Figure 1, unless otherwise specified. Limits apply for TA = 25°C. Units (Limits) AUD4990 Symbol IDD Parameter Quiescent Power Supply Current ISD Shutdown Current VOS Output Offset Voltage Conditions Typical Limit VIN = 0V, IO = 0A, No Load 3.5 7.5 mA (max) VIN = 0V, IO = 0A, 8Ω Load 4.5 9 mA (max) VSD = VSD Mode 0.1 2.0 µA (max) 25 mV (max) Output Power (8Ω) THD+N = 10% (max); f = 1kHz 0.5 W (4Ω) THD+N = 10% (max); f = 1kHz 0.8 W PO V1.45 4 http://www.analogexpress.com In many applications, output signal from a microcontroller is used to control the shutdown circuitry, which provides a quick, smooth transition to shutdown. Another solution is to use a single-throw switch in conjunction with an external resistor (pull-up or pull-down, depending on shutdown mode selection). This scheme guarantees that the shutdown pin will not float, thus preventing unwanted state changes. Selection of External Components The external components will be the one of the important factor to affect the amplifier performance, proper selection on them will allow system function in more efficiency way. The AUD4990 should be used in low gain configurations to minimize THD+N values, and maximize the signal to noise ratio. Besides gain, another major consideration in system performance is the closed loop bandwidth of the amplifier. To a large extent, the bandwidth is dictated by the choice of external components. The input coupling capacitor forms a first order high pass filter, which limits low frequency response, and should be chosen based on needed frequency response for a few distinct reasons. In many cases the speakers used in portable systems, whether internal or external, have little ability to reproduce signals below 100Hz to 150Hz. Thus, using a large input capacitor may not increase actual system performance. Besides minimizing the input capacitor size, careful consideration should be paid to the bypass capacitor value. It will determine how fast the chip turns on. http://www.analogexpress.com 5 V1.45 2 Watt Audio Power Amplifier with Selectable Shutdown Shutdown Control In order to reduce the power consumption, there is shutdown circuitry employed to switch off the amplifier bias. The circuit contains two input pins, Shutdown Mode pin (SD Mode) and Shutdown pin with selectable input level, this allows the user can use either logic high or logic low level signal to control the shutdown circuit. Normally, SD Mode pin is permanently tied to VDD or GND, and the Shutdown pin is used to control the shutdown function. With SD Mode is tied to VDD, the device will then become a shutdown high device, that means if high level logic signal is presenting on Shutdown pin the device will then enter the shutdown mode. In other side, if SD Mode is tied to GND, a low level logic signal on Shutdown pin will active the shutdown function. Or simply, once the same logic level is presenting on two control pins, the shutdown function will be activated. To avoid unwanted state changes, the shutdown pin should be tied to a definite voltage. AUD4990 Application Information AUD4990 Typical Performance Characteristics 2 Watt Audio Power Amplifier with Selectable Shutdown V1.45 THD+N vs Output Power VDD = 3V, RL = 8Ω, and f = 1kHz THD+N vs Output Power VDD = 3V, RL = 4Ω, and f = 1kHz THD+N vs Output Power VDD = 2.7V, RL = 8Ω, and f = 1kHz THD+N vs Output Power VDD = 2.7V, RL = 4Ω, and f = 1kHz THD+N vs Output Power VDD = 5V, RL = 8Ω, and f = 1kHz THD+N vs Frequency VDD = 5V, RL = 8Ω, and PO = 500mW 6 http://www.analogexpress.com Enable Current vs VDD Enable Current vs Enable Voltage 2 Watt Audio Power Amplifier with Selectable Shutdown THD+N vs Frequency VDD = 3.3V, RL = 4Ω, and PO = 500mW AUD4990 THD+N vs Frequency VDD = 3.3V, RL = 8Ω, and PO = 350mW Power Supply Rejection Ratio (PSRR) vs Frequency VDD = 5V, RL = 8Ω, Input 10Ω terminated http://www.analogexpress.com 7 V1.45 AUD4990 Package Dimensions 2 Watt Audio Power Amplifier with Selectable Shutdown http://www.analogexpress.com 8 V1.45 2 Watt Audio Power Amplifier with Selectable Shutdown V1.45 9 http://www.analogexpress.com AUD4990 Package Dimensions AUD4990 2 Watt Audio Power Amplifier with Selectable Shutdown LIFE SUPPORT POLICY ANALOG EXPRESS’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEM WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF ANALOG EXPRESS. As used herein: 1. Life support devices or systems are devices or systems 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. 2. A critical component is any component of 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. Analog Express Inc. US Tel: (1) 713 666 9459 HK Tel: (852) 2527 5009 www.analogexpress.com Email: [email protected] V1.45 10 http://www.analogexpress.com