EUA5544 Class AB Stereo Headphone Driver with Shutdown DESCRIPTION FEATURES The EUA5544 is pin compatible with the BH3541/4, and functionally compatible with the TPA611× series and LM488 × series. As the EUA5544 contains advanced depop circuitry which eliminates pops & clicks during shutdown-on and shutdown-off, it can reduces a capacitor and resistor compared to Mute solution of other devices. The EUA5544 features an advantage of low-power consumption shutdown mode, activated by driving the shutdown pin with logic low. And it also allows fast turn-on with 1µF bypass capacitor (CB). z No Switch On/Off Clicks z Wide Power Supply Operation 2.5V– 6V z Mute Function Compatibility z High Signal-to-Noise Ratio z Low Distortion z Large Output Voltage Swing z Excellent Power Supply Ripple Rejection z High Crosstalk Immunity＞85dB z Low Quiescent Current z Ultra-low Shutdown Current …0.02µA typical z Short-circuit Protection z Integrated Voltage Divider (VDD/2) to Eliminate External Resistors z Available in SOP-8 z RoHS Compliant and 100% Lead (Pb)-Free The EUA5544 is an integrated class AB stereo headphone amplifier capable of delivering 68mW per channel of continuous average power into a 16Ω load or 35mW per channel into a 32Ω load from a 5V power supply. It also can operate from a 3V supply, capable of delivering 24 mW into a 32Ω load. The EUA5544 further integrates a voltage divider inside the chip. Thus, the external resistors can be eliminated. The EUA5544 has a fixed gain of 6dB so that external gain setting is unnecessary. APPLICATIONS Typical Application Circuit DS5544 Ver 2.4 Oct.2007 1 z Headphone Amplifier for CD-ROMs z Portable Audio Equipment EUA5544 Pin Configurations Package Type Pin Configurations EUA5544 (Plastic SOP-8) Pin Description PIN I/O OUTA O A channel output pin Shutdown I Chip disable control input, low active and high for normal operating INA I A channel input terminal VSS DESCRIPTION Power ground pin INB I B channel input terminal BIAS I Right channel bias input pin OUTB O B channel output pin VDD Power input pin Block Diagram DS5544 Ver 2.4 Oct.2007 2 EUA5544 Ordering Information Order Number Package Type Marking Operating Temperature range EUA5544DIR1 SOP-8 xxxxx EUA5544 -40 °C to 85°C EUA5544 □ □ □ □ Lead Free Code 1: Lead Free 0: Lead Packing R: Tape& Reel Operating temperature range I: Industry Standard Package Type D: SOP DS5544 Ver 2.4 Oct.2007 3 EUA5544 Absolute Maximum Ratings ▓ ▓ ▓ ▓ ▓ ▓ Input voltage - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Maximum Junction Temperature - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Storage Temperature Range - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Power Dissipation PD@)TA=25 °C SOP-8 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Package Thermal Resistance SOP-8, θjA - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Electrostatic Discharge - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 7V 150°C -60°C to150°C 0.625W 160°C /W -3000 to 3000V(1) -200 to 200V(2) Notes: (1) Human body mode: C=100pF, R=1500Ω, 3 positive pulses plus 3 negative pulses (2) Machine mode: C=200pF, L=0.5mH, R=0Ω, 3 positive pulses plus 3 negative pulses Electrical Characteristics VDD = 5V Vin = -6dBV, RL = 32Ω, f = 1KHz, CB = 1µF, TA = 25°C (unless otherwise specified) Symbol Parameter VDD IQ ISD Supply Voltage Quiescent Current Shutdown Current Shutdown Voltage Input High Shutdown Voltage Input Low Differential Channel Voltage Gain Voltage Gain Total Harmonic Distortion plus Noise VSDIH VSDIL △GVCL GVCL THD+N Conditions Min. 2.5 Vin = 0V VSD = GND EUA5544 Typ. Max. 5.0 3.5 0.02 6.0 5 Unit V mA µA 1.8 V 0.4 V -0.5 0 0.5 dB 4 6 8 dB BW < 80KHz 0.02 0.1 % RL = 32Ω, THD+N＜0.1%, BW＜80KHz 31 mW RL = 16Ω, THD+N＜0.1%, BW＜80KHz 62 mW Po Output Power VN Output Noise Voltage BW = 20~20KHz -95 dBV CS Channel Separation f = 20~20KHz 90 dB ATT Shutdown Attenuation Vin = 1V, SD = Low 70 dB PSRR Ripple Rejection FRR=100Hz, VRR= -20dBV 60 dB DS5544 Ver 2.4 Oct.2007 4 55 EUA5544 Electrical Characteristics VDD = 3.0V Vin = -6dBV, RL = 32Ω, f = 1KHz, CB = 1µF, TA = 25°C (unless otherwise specified) Symbol Parameter Conditions EUA5544 Min. Typ. Max. Unit IQ Quiescent Current Vin = 0V 2.4 mA ISD Shutdown Current 3 VSD = GND 0.02 µA RL = 32Ω, THD+N＜0.1%, BW＜80KHz 24 mW RL = 16Ω, THD+N＜0.1%, BW＜80KHz 37 mW Po Output Power VN Output Noise Voltage BW = 20∼20KHz -95 -94 dBV PSRR Ripple Rejection FRR=100Hz, VRR= -20dBV 55 60 dB Electrical Characteristics VDD = 2.5V Vin = -6dBV, RL = 32Ω, f = 1KHz, CB = 1uF, TA = 25°C (unless otherwise specified) Symbol Parameter Conditions EUA5544 Min. Typ. Max. Unit IQ Quiescent Current Vin = 0V 2.2 mA ISD Shutdown Current VSD = GND 0.02 µA Po Output Power RL = 32Ω, THD+N＜0.1%, BW＜80KHz 17 mW RL = 16Ω, THD+N＜0.1%, BW＜80KHz 22 mW VN Output Noise Voltage BW = 20~20KHz -94 dBV PSRR Ripple Rejection FRR=100Hz, VRR= -20dBV 60 dB DS5544 Ver 2.4 Oct.2007 5 3 EUA5544 Typical Operating Characteristics DS5544 Ver 2.4 Oct.2007 6 EUA5544 DS5544 Ver 2.4 Oct.2007 7 EUA5544 DS5544 Ver 2.4 Oct.2007 8 EUA5544 Application Note Power Supply Decoupling, CS Output Coupling Capacitors, Cc EUA5544 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output total harmonic distortion (THD) is as low as possible. Power supply decoupling also prevents the oscillations causing by long lead length between the amplifier and the speaker. Typical single-supply audio amplifiers that drive single-ended (SE) headphones use a coupling capacitor on each SE output. This output coupling capacitor blocks the half-supply voltage to which the output amplifiers are typically biased and couples the audio signal to the headphones. The output coupling capacitor and impedance of the load form a high-pass filter governed by equation. Applications that employ a 5V regulator typically use a 10µF in parallel with a 0.1µF filter capacitors to stabilize the regulator’s output, reduce noise on the supply line, and improve the supply’s transient response. However, this does not eliminate the need for a local bypass capacitor connected between the EUA5544’s supply pins and ground. A bypass capacitor value in the range of 0.1µF to 1µF is recommended for CS. fc (highpass)=1/(2 π RLCC) For example, a 220µF capacitor with an 32Ω speaker would attenuate low frequencies below 22Hz. The main disadvantage, from a performance standpoint, is the load impedance is typically small, which drives the low-frequency corner higher degrading the bass response. Large values of CC are required to pass low frequencies into the load. Input Capacitor Ci Amplifying the lowest audio frequencies requires a high value input coupling capacitor, Ci. A high value capacitor can be expensive and may compromise space efficiency in portable designs. In many cases, however, the headphones used in portable systems have little ability to reproduce signals below 60Hz. Applications using headphones with this limited frequency response reap little improvement by using a high value input capacitor. Micro Power Shutdown The voltage applied to the Shutdown pin controls the EUA5544 shutdown function. Activate micro-power shutdown by applying a logic-low voltage to the Shutdown pin. When active, the EUA5544 micro-power shutdown feature turns off the amplifier’s bias circuitry, reducing the supply current. In addition to system cost and size, turn-on time is affected by the size of the input coupling capacitor Ci. A larger input coupling capacitor requires more charge to reach its quiescent DC voltage. This charge comes from the output via the feedback. Thus, by minimizing the capacitor size based on necessary low frequency response, turn-on time can be minimized. A small value of Ci, 1µF, is recommended. There are a few ways to control the micro-power shutdown. These include using a single-pole, single-throw (SPST) switch, a microprocessor, or a microcontroller. When using a switch, connect an external pull-up resistor between the Shutdown pin and VDD. Connect the switch between the Shutdown pin and ground. Select normal amplifier operation by opening the switch. Closing the switch connects the Shutdown pin to ground, activating micro-power shutdown. The switch and resistor guarantee that the Shutdown pin will not float. This prevents unwanted state changes. In a system with a microprocessor or microcontroller, use a digital output to apply the control voltage to the Shutdown pin. Bypass Capacitor, CB Besides minimizing the input capacitor sizes, careful consideration should be paid to the bypass capacitor size. The bypass capacitor, CB, is the most critical component to minimize turn-on pops since it determines how fast the EUA5544 turns on. The slower the EUA5544’s output ramp to their quiescent DC voltage (nominally 1/2 VDD), the smaller the turn-on pop. DS5544 Ver 2.4 Oct.2007 (4) 9 EUA5544 Packaging Information SOP-8 SYMBOLS A A1 D E E1 L b e DS5544 Ver 2.4 Oct.2007 MILLIMETERS MIN. MAX. 1.35 1.75 0.10 0.25 4.90 5.80 6.20 3.90 0.40 1.27 0.31 0.51 1.27 10 INCHES MIN. 0.053 0.004 0.193 0.228 0.153 0.016 0.012 0.050 MAX. 0.069 0.010 0.244 0.050 0.020