NJU8754 Analog Signal Input Monaural Class D Power Amplifier PACKAGE OUTLINE GENERAL DESCRIPTION The NJU8754 is an analog signal input monaural class D power amplifier. The NJU8754 includes Inversion operatinal amplifier input circuit, PWM modulator, an output-short protector and a low voltage detector. The NJU8754 incorporates BTL amplifier, which eliminate AC coupling capacitors, capable of driving up to 0.6W at 3.6V supply voltage with simple external LC low-pass filters. The NJU8754 features high power-efficiency by class-D operation and very small package, and is suited for cellular phone, PDA, etc. NJU8754V NJU8754KM1 FEATURES Operating Voltage :2.7 to 5.25V Monaural Analog Signal Input Monaural BTL Output :1.2W at 5V into 8Ohms :0.6W at 3.6V into 8Ohms Standby(Hi-Z), Mute Control Built-in Short Protector Built-in Low Voltage Detector CMOS Technology Package Outline :SSOP10, QFN20-M1 15 NC OUTP VDDO OUTN NC PIN CONFIGURATION 11 16 1 2 3 4 5 10 9 8 7 6 SSOP10 VSS OUTP VDDO OUTN VSS VSS VSS NC STBYB NC 20 6 1 NC IN COM MUTEB NC VDD IN COM MUTEB STBYB 10 VSS VSS NC VDD NC 5 QFN20-M1 Ver.2008-07-14 -1- NJU8754 BLOCK DIAGRAM VDD IN VSS - OUTP + COM Pulse Width Modulator VDDO OUTN + Short Protection Soft Start Low BATT Protection Control Logic MUTEB STBYB PIN DESCRIPTION No. SYMBOL I/O VDD IN COM - I - 4 MUTEB I 7 STBYB I SSOP10 1 2 3 QFN20-M1 19 2 3 4 5 FUNCTION Power supply : VDD=3.6V Signal input Analog common Mute control Low : Mute ON High : Mute OFF Standby control Low : Standby ON High : Standby OFF Power GND : VSS=0V Negative output Output power supply Positive output 9,10, 6,17 VSS - 12 OUTN O 13 VDDO - 14 OUTP O 1,5,6,8, - NC - Non connection 11,15,18,20 *The relations of "VSS= 0V" and "VDD= VDDO" must be maintained. *VSS(SSOP10:Terminal No.6,10, QFN20-M1:Terminal No.9,10,16,17) should be connected at a nearest point to the IC. *VDDO(SSOP10:Terminal No.8, QFN20-M1:Terminal No.13) should be connected at a nearest point to the IC. *MUTEB(SSOP10, QFN20-M1:Terminal No.4) and STBY(SSOP10:Terminal No.5, QFN20-M1:Terminal No.7) must be connected to VDD, when these terminals are not used. 6, 10 7 8 9 -2- Ver.2008-07-14 NJU8754 NJU3555 FUNCTIONAL DESCRIPTION (1) Signal Output The OUTP and OUTN generate PMW output signal, which will be converted to analog signal via external 2nd-order or higher LC filter. A switching regulator with a high response against a voltage fluctuation is the best selection for the VDDO, which is the power supply for output driver. To obtain better T.H.D. performance, the stabilization of the power is required. (2) Standby By setting the STBYB terminal to "L", the standby mode is enabled. In the standby mode, the entire functions of the NJU8754 enter a low-power state, and the output terminals(OUTP and OUTN) are in high impedance. (3) Mute By setting the MUTEB terminal to "L", the Mute function is enabled, and the output terminals(OUTP and OUTN) output square wave(Duty: 50%). (4) Low Voltage Detector When the power supply voltage drops down to below VDD(MIN), the internal oscillation is halted not to generate unwanted frequency, and the output terminals(OUTP and OUTN) become in high impedance. (5) Short Protection Circuit The short protector, which protects the NJU8754 from high short-circuit current, turns off the output driver. After about 5 seconds from the protection, the NJU8754 returns to normal operation. The short protector is enabled in response to following accidents. Short between OUTP and OUTN Short between OUTP and VSS Short between OUTN and VSS Note 1) The detectable current and the period for the protection depend on the power supply voltage and ambient temperature. Note 2) The short protector is not effective for a long term short-circuit but for an instantaneous accident. Continuous high-current may cause permanent damage to NJU8754. Ver.2008-07-14 -3- NJU8754 ABSOLUTE MAXIMUM RATINGS (Ta=25C) PARAMETER SYMBOL Input Voltage Operating Temperature Storage Temperature VDD VDDO Vin Topr Tstg Power Dissipation PD Supply Voltage RATING UNIT -0.3 to +5.5 V -0.3 to +5.5 V -0.3 to VDD+0.3 V -40 to +85 C -40 to +125 C 360 (SSOP10) mW 620 (QFN20-M1) * : Mounted on two-layer board of based on the JEDEC. Note 1) All voltage are relative to "VSS= 0V" reference. Note 2) The LSI must be used inside of the "Absolute maximum ratings". Otherwise, a stress may cause permanent damage to the LSI. Note 3) De-coupling capacitors for VDD-VSS and VDDO-VSS should be connected for stable operation. Note 4) Power Dissipation The class-D amplifiers are more power efficient, and dissipate power less than general analog-amplifiers. In theory, the NJU8754 actualize quite high output-power such as 1.2W at =5V operation with 8ohms load, it looks as if the NJU8754 exceeds the absolute maximum rating of the power dissipation. However, in practice, the effective output-power of usual music sound is only about 1/10 of its maximum output power, thus it may never exceed the absolute maximum rating. The maximum power dissipation in the system is calculated, as shown below. Pdmax(W) = (Tjmax(C) - Ta(C)) /ja Pdmax: Maximum Power Dissipation, Tjmax: Junction Temperature = 125C Ta: Ambient Temperature, ja: Thermal Resistance of package(SSOP10) = 400C/W Power dissipation of the NJU8754 itself is calculated, as shown below. Pd(W) = PO(W) X RO() / RL() + PdIC(W) Pd: Power Dissipation, PO: Output Power, RO: Internal Resistance(output driver) RL: Load Resistance, PdIC: Power of internal circuit -4- Ver.2008-07-14 NJU8754 NJU3555 ELECTRICAL CHARACTERISTICS (Ta=25C, VDD=VDDO= 3.6V, VSS= 0V, Input Signal=1kHz, Input Signal Level=200mVrms, Frequency Band=20Hz to 20kHz, Load Impedance=8, 2nd-order 34kHz LC Filter(Q=0.85)) PARAMETER VDD,VDDO Supply Voltage Input Impedance Voltage Gain Output Power Efficiency Output THD Output Power S/N Operating Current (Standby) Operating Current (No signal input) Input Voltage Input Leakage Current SYMBOL CONDITIONS VDD ZIN IN terminal AV Eeff Output THD=10% VDD=VDDO=5.0V, Po=600mW THD VDD=VDDO=3.6V, Po=300mW VDD=VDDO=5.0V Output THD=10% Po VDD=VDDO=3.6V Output THD=10% SN A weight IST VDD=VDDO=5.0V No Filter, No Load IDD VDD=VDDO=3.6V No Filter, No Load MUTEB, STBYB terminals VIH MUTEB, STBYB terminals VIL MUTEB, STBYB terminals ILK MIN 2.7 80 TYP 3.6 20 23 83 0.05 0.07 MAX 5.25 0.08 0.1 UNIT V k dB % Note 4 % 1.2 W 0.6 75 - 80 - 1 4 6 2.5 5 - VDD 0.3VDD 0.1 dB A mA 0.7VDD 0 - V V A Note 5) Test system of the output THD and S/N The output THD and S/N are tested in the system shown in Figure1, where a 2nd-order LC LPF and another filter incorporated in an audio analyzer are used. Input Signal NJU8754 2nd-order LC LPF Filter 20kHz (AES17) NJU8754 Test Board THD Measuring Apparatus Audio Analyzer Figure 1. Output THD and S/N Test System 2nd-order LPF Filters Ver.2008-07-14 : fc=34kHz / Refer to "Typical Application Circuit". : 22Hz HPF + 20kHz LPF(AES17) (with the A-Weight filter for S/N and Dynamic-range tests) -5- NJU8754 TYPICAL APPLICATION CIRCUIT <LCR Filter Configuration 22H 10F 0.1F VDD OUTP(9) VDD(1) 2.2F IN IN(2) 10F 22H NJU8754 VSS(10) COM(3) 1F OUTN(7) VDDO(8) 8 Speaker 1F 0.1F 47F VDD VSS(6) MUTEB(4) STBYB(5) SSOP10 22H 10F 0.1F VDD OUTP(14) VSS(16,17) 2.2F IN IN(2) 10F COM(3) NJU8754 VDD(19) 1F 22H OUTN(12) VDDO(13) 0.1F 47F 8 Speaker 1F VDD VSS(9,10) MUTEB(4) STBYB(7) QFN20-M1 -6- Ver.2008-07-14 NJU8754 NJU3555 <LR Filter Configuration> 33H 10F 0.1F VDD OUTP(9) VDD(1) 2.2F IN IN(2) 10F 8 Speaker NJU8754 VSS(10) COM(3) OUTN(7) VDDO(8) 0.1F 47F VDD VSS(6) MUTEB(4) STBYB(5) SSOP10 33H 10F 0.1F VDD OUTP(14) VSS(16,17) 2.2F IN IN(2) 10F COM(3) NJU8754 VDD(19) 8 Speaker OUTN(12) VDDO(13) 0.1F 47F VDD VSS(9,10) MUTEB(4) STBYB(7) QFN20-M1 Using the LCR filter the power consumption is somewhat lower than using the LR filter power consumption when no signal input. The THD+N is somewhat influenced by the LR filter more than the LCR filter. Please test the circuit carefully to fit your application. Note 6) De-coupling capacitors must be connected between each power supply terminal and GND. The capacity value should be adjusted on the application circuit and the operation temperature. It may malfunction if capacity value is small. Note 7) The power supply for VDDO requires fast driving response performance such as a switching regulator for better THD. THD performance becomes worse by ripple if the capacity of De-coupling capacitor is small. Note 8) The above circuit shows only application example and does not guarantee the any electrical characteristics. Therefore, please test the circuit carefully to fit your application. The cutoff frequency of the LC filter influences the quality of sound. The Q factor of the LC filter must be less than "1". Otherwise, the operating current increases when the frequency of input signal is closed to the cutoff frequency. Note 9) The transition time for MUTEB and STBYB signals must be less than 100s. Otherwise, a malfunction may be occurred. Note 10) (1) - (19) indicates terminal number. Ver.2008-07-14 -7- NJU8754 [CAUTION] The specifications on this databook are only given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights. -8- Ver.2008-07-14