® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function FEATURES GENERAL DESCRIPTION 2.5V~5.5V Power supply. Thermal shutdown Protection. Low current shutdown mode. No capacitors and networks or bootstrap capacitors required. Low noise during turn-on and turn-off transitions. User selectable stereo headphone function. User selectable shutdown high or low logic level. (SOP package only) Lead free and green package available. (RoHS Compliant) Space Saving Package -- 16-pin QFN 3*3 Package. -- 16-pin QFN 4*4 Package. -- 16-pin SOP Package. The LY8661 is a dual bridge-connected audio power amplifier. It is capable of driving 4Ω speaker load at a continuous average output of 2.0W / 10% distortion (THD+N) from a 5.5V power supply. It primarily designed for high quality application in other portable communication device and portable and desktop computers device. The audio amplifier features low power consumption in shutdown mode. Shutdown may be enabled by either logic high or low depending on mode selection(SOP package only). And it has an internal thermal shutdown protection feature. LY8661 audio amplifier was designed specifically to provide high quality output power with a minimal amount of external components. The LY8661 does not require output capacitors, and it is ideally suited for other low voltage applications or portable electronic devices where minimal power consumption is a primary requirement. APPLICATION Portable electronic devices Portable and desktop computers Cell Phones Multimedia Monitors Audio System PIN CONFIGURATION Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 1 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function PIN DESCRIPTION SYMBOL Pin No. DESCRIPTION QFN SOP 1 6 2/11 12/16 -OUTA 3 11 Negative BTL output of A channel. INA 4 10 Input of A channel. GND 5/6/7/13/16 2/5 Ground. INB 8 13 Input of B channel. BYPASS 9 14 Bypass capacitor which provides the common mode voltage. -OUTB 10 15 Negative BTL output of B channel. +OUTB HP Sense (Option) SHUTDOWN 12 1 14 3 15 4 Positive BTL output of B channel. Headphone sense pin option. (If None headphone function must connect to GND). Shutdown the device pin. SD Mode -- 7 Shutdown Mode Selectable. NC -- 8/9 +OUTA VDD Positive BTL output of A channel. Power supply. No connection. Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 2 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function APPLICATION CIRCUIT Figure 1. Without Headphone Typical Application Circuit (QFN16) Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 3 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function Figure 2. With Headphone Typical Application Circuit (QFN16) Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 4 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function Figure 3. Without Headphone Typical Application Circuit (SOP16) Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 5 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function Figure 4. With Headphone Typical Application Circuit (SOP16) Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 6 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function ORDERING INFORMATION LY 8 661 VV V : Package Type EB : 16-Pin QFN 3*3 EL : 16-Pin QFN 4*4 SL : 16-Pin SOP Product Name A : Product Line LY : Lyontek Product Number Prefix ABSOLUTE MAXIMUN RATINGS* PARAMETER Supply Voltage Operating Temperature Input Voltage Storage Temperature Power Dissipation ESD Susceptibility Junction Temperature Soldering Information SYMBOL VDD TA VI TSTG PD VESD TJMAX Vapor Phase (60 sec.) Infrared (15 sec.) RATING 6.0 -40 to 85 (I grade) -0.3V to VDD +0.3V -65 to 150 Internally Limited 2000 150 215 220 Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 7 FAX: 886-3-6668836 UNIT V ℃ V ℃ W V ℃ ℃ ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function DC ELECTRICAL CHARACTERISTICS (VDD=5.0V, TA=25℃) SYMBOL TEST CONDITION IDD VDD=5.0V, 8Ω Load (BTL) VSHUTDOWN = 0V, ISD HP sense= GND PARAMETER Power Supply Current Shutdown Current Shutdown, Headphone High Input Voltage Shutdown, Headphone Low Input Voltage Wake-up time Output Offset Voltage Sense Sense MIN. - TYP. 12.0 MAX. 21.5 UNIT mA - 0.1 1.0 µA VSDIH 1.4 - - V VSDIL - - 0.4 V - 172 7.0 50.0 ms mV - 1.1 - - 1.4 - - 1.4 - - 1.8 - - 2.0 - - 90 - - 165 - - 0.11 - % - 62 (f = 217Hz) 66 (f = 1kHz) - dB - 37.5 - - 15 - 150 - 170 1.0 190 - TWU VOS Bypass cap.=1.0uF THD+N = 1%, f = 1 kHz, RL=8Ω THD+N = 10%, f = 1 kHz RL=8Ω THD+N = 1%, f = 1 kHz RL=4Ω THD+N = 10%, f = 1 kHz Output Power Po RL=4Ω THD+N = 10%, f = 1 kHz RL=4Ω (at 5.5V) THD+N = 0.1%, f = 1 kHz, RL=32Ω (SE Mode) THD+N = 0.1%, f = 1 kHz, RL=16Ω (SE Mode) Po = 0.4 Wrms; f = 1kHz, Total Harmonic Distortion+ Noise THD+N RL=8Ω Vripple = 200mV sine p-p Input terminated with 10Ω Power Supply Rejection Ratio PSRR to GND Output voltage noise Thermal Shutdown Temperature Shutdown Time Vn TSD TSDT f = 20 Hz to 20 kHz, A-weighting f = 20 Hz to 20 kHz, A-weighting (SE mode) 8 Ω load W mW uV Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 8 FAX: 886-3-6668836 ℃ ms ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function DC ELECTRICAL CHARACTERISTICS (VDD=3.6V, TA=25℃) SYMBOL TEST CONDITION IDD VDD=3.6V, 8Ω Load (BTL) VSHUTDOWN = 0V ISD HP sense= GND PARAMETER Power Supply Current Shutdown Current Shutdown, Headphone High Input Voltage Shutdown, Headphone Low Input Voltage Wake-up time Output Offset Voltage Sense Sense MIN. - TYP. 10.0 MAX. 16.5 UNIT mA - 0.1 2.0 µA VSDIH 1.4 - - V VSDIL - - 0.4 V - 82 7.0 50 ms mV - 0.5 - - 0.65 - - 0.65 - - 0.8 - - 45 - TWU VOS Bypass cap.=1.0uF THD+N = 1%, f = 1 kHz, RL=8Ω THD+N = 10%, f = 1 kHz RL=8Ω THD+N = 1%, f = 1 kHz RL=4Ω Output Power Po THD+N = 10%, f = 1 kHz RL=4Ω THD+N = 0.1%, f = 1 kHz, RL=32Ω (SE Mode) THD+N = 0.1%, f = 1 kHz, RL=16Ω (SE Mode) Po = 0.2 Wrms; f = 1kHz, Total Harmonic Distortion+ Noise THD+N RL=8Ω Vripple = 200mV sine p-p Input terminated with 10Ω Power Supply Rejection Ratio PSRR to GND Output voltage noise Thermal Shutdown Temperature Shut Down Time Vn TSD TSDT f = 20 Hz to 20 kHz, A-weighting f = 20 Hz to 20 kHz, A-weighting (SE mode) 8 Ω load W mW - 83 - - 0.12 - % - 56 (f = 217Hz) 62 (f = 1kHz) - dB - 37.5 - - 15 - 150 - 170 1.0 190 - uV Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 9 FAX: 886-3-6668836 ℃ ms ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function APPLICATION INFORMATION The LY8661’s QFN package provides a low thermal resistance between the die and the PCB to which the part is mounted and soldered. This allows rapid heat transfer from the die to the surrounding PCB copper traces, ground plane and, finally, surrounding air. The result is a low voltage audio power amplifier that produces 2.0W at 10% THD with a 4Ω load. This high power is achieved through careful consideration of necessary thermal design. Failing to optimize thermal design may compromise the LY8661’s high power performance and activate unwanted, though necessary, thermal shutdown protection. POWER SUPPLY BYPASSING As with any power amplifier, proper supply bypassing is critical for low noise performance and high power supply rejection. Applications that employ a 5V regulator typically use a 10 μF in parallel with a 0.1 μF filter capacitor to stabilize the regulator’s output, reduce noise on the supply line, and improve the supply’s transient response. However, their presence does not eliminate the need for a local 1.0 μF tantalum bypass capacitance connected between the LY8661’s supply pins and ground. Do not substitute a ceramic capacitor for the tantalum. Doing so may cause oscillation. Keep the length of leads and traces that connect capacitors between the LY8661’s power supply pin and ground as short as possible. MICRO-POWER SHUTDOWN The voltage applied to the SHUTDOWN pin controls the LY8661’s shutdown function. Activate micro-power shutdown by applying GND to the SHUTDOWN pin. When active, the LY8661’s micro-power shutdown feature turns off the amplifier’s bias circuitry, reducing the supply current. The low 0.1 μA typical shutdown current is achieved by applying a voltage that is as near as GND as possible to the SHUTDOWN pin. A voltage that is more than GND may increase the shutdown current. Table 1 shows the logic signal levels that activate and deactivate micro-power shutdown and headphone amplifier operation. There are a few ways to control the micro-power shutdown. These include using a single-pole, single-throw switch, a microprocessor, or a microcontroller. When using a switch, connect an external 20k resistor between the SHUTDOWN pin and Ground. Connect the switch between the SHUTDOWN pin VDD. Select normal amplifier operation by closing the switch. Opening the switch sets the SHUTDOWN pin to ground through the 20k resistor, which activates the 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 a microcontroller, use a digital output to apply the control voltage to the SHUTDOWN pin. Driving the SHUTDOWN pin with active circuitry eliminates the pull up resistor. Shutdown Pin Logic High Logic High Logic Low TABLE 1. Logic Level Truth Table Headphone Jack Operational Output Sense Pin Mode Low (HP not Plugged in) BTL High (HP Plugged in) Single-Ended High or Low Don’t care Micro-Power Shutdown HEADPHONE SENSE AND HEADPHONE LOGIC IN FUNCTIONS Applying a logic level to the LY8661’s HP Sense headphone control pin turns off Amp. A (+out) and Amp. B (+out) muting a bridged-connected load. Quiescent current consumption is reduced when the IC is in this single-ended mode. Figure 2 shows the implementation of the LY8661’s headphone control function. With no headphones connected to the headphone jack, the R5-R6 voltage divider sets the voltage applied to the HP Sense pin (pin 14) at approximately 50mV. This 50mV enables Amp A (+out) and Amp B (+out) placing the LY8661 in bridged mode operation. While the LY8661 operates in bridged mode, the DC potential across the load is essentially 0V. Therefore, even in an ideal situation, the output swing cannot cause a false single-ended trigger. Connecting headphones to the headphone jack disconnects the headphone jack contact pin from −OUTA and allows R7 to pull the HP Sense pin up to VDD. Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 10 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function This enables the headphone function, turns off Amp A (+out) and Amp B (+out) which mutes the bridged speaker. The amplifier then drives the headphones, whose impedance is in parallel with resistors R5 and R6. These resistors have negligible effect on the LY8661’s output drive capability since the typical impedance of headphones is 32Ω. Figure 5 also shows the suggested headphone jack electrical connections. The jack is designed to mate with a four wire (or three wire)plug. The plug’s tip and ring should each carry one of the two stereo output signals, whereas the sleeve should carry the ground return. The headphone jack with one control pin contact is sufficient to drive the HP Sense pin when connecting headphones. As outlined above driving the Speaker (BTL) and Headphone (SE) loads simultaneously using LY8661 is simple and easy. However this configuration will only work if the HP Logic pin is used to control the BTL/SE operation and HP Sense pin is connected to GND(Figure 6). FIGURE 5. With Headphone Circuit (QFN Type) FIGURE 6. Without Headphone Circuit (QFN Type) Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 11 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function Bypass Capacitor Value Selection Besides minimizing the input capacitor size, careful consideration should be paid to value of C4, the capacitor connected to the BYPASS pin. Since C4 determines how fast the LY8661 settles to quiescent operation, its value is critical when minimizing turn-on pops. The slower the LY8661’s outputs ramp to their quiescent DC voltage (nominally 1/2 VDD), the smaller the turn-on pop. Choosing C4 equal to 1.0 μF along with a small value of C2,C3 (in the range of 0.1 μF to 0.39 μF), produces a click-less and pop-less shutdown function. As discussed above, choosing C1 no larger than necessary for the desired bandwith helps minimize clicks and pops. Connecting a 1μF capacitor, C4, between the BYPASS pin and ground improves the internal bias voltage’s stability and improves the amplifier’s PSRR. OPTIMIZING CLICK AND POP REDUCTION PERFORMANCE The LY8661 contains circuitry that minimizes turn-on and shutdown transients or “clicks and pop”. For this discussion, turn-on refers to either applying the power supply voltage or when the shutdown mode is deactivated. When the part is turned on, an internal current source changes the voltage of the BYPASS pin in a controlled, linear manner. Ideally, the input and outputs track the voltage applied to the BYPASS pin. The gain of the internal amplifiers remains unity until the voltage on the bypass pin reaches 1/2 VDD. As soon as the voltage on the bypass pin is stable, the device becomes fully operational. Although the BYPASS pin current cannot be modified, changing the size of C4 alters the device’s turn-on time and the magnitude of “clicks and pops”. Increasing the value of C4 reduces the magnitude of turn-on pops. However, this presents a tradeoff: as the size of C4 increases, the turn-on time increases. There is a linear relationship between the size of C4 and the turn-on time. Here are some typical turn-on times for various values of C4: In order eliminate “clicks and pops”, all capacitors must be discharged before turn-on. Rapidly switching VDD on and off may not allow the capacitors to fully discharge, which may cause “clicks and pops”. TABLE 2. C4 and TON Truth Table TON (Typ.) at 5.0V C4 1.0uF 172 ms 0.47uF 76 ms 0.33uF 60 ms 0.22uF 50 ms 0.1uF 36 ms Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 12 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function PACKAGE OUTLINE DIMENSION 16-Pin QFN 3X3 Package Outline Dimension Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 13 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function 16-Pin QFN 4X4 Package Outline Dimension Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 14 FAX: 886-3-6668836 ® LY8661 Rev. 1.8 Dual 2.0W/CH Stereo Audio Amplifier include Headphone Function 16 Pin SOP Package Outline Dimension Lyontek Inc. reserves the rights to change the specifications and products without notice. 5F, No. 2, lndustry E . Rd. IX, Science-Based Industrial Park, Hsinchu 300, Taiwan TEL: 886-3-6668838 15 FAX: 886-3-6668836