NJM2706 3D Surround Audio Processor with Dynamic Bass Boost ■ GENERAL DESCRIPTION The NJM2706 is the 3D surround audio processor with dynamic bass boost, regenerates rich sound field with only small two speakers. The NJM2706 performs NJRC original surround technology realizing natural surround sound field regarded center orientation and NJRC original dynamic bass boost technology provides graceful bass sound with low distortion. It is suitable for mini-component, CD radio-cassette, TV, speaker system and others. ■ PACKAGE OUTLINE NJM2706VE1 NJM2706M NJM2706L ■ FEATURES ● Operating Voltage +4.7V to +13.0V ● Wide Dynamic Range 3.1Vrms typ. ● Low Output Noise 8.9µVrms typ. ● "eala" 3D Surround Function (Stereo only) ● Dynamic Bass Boost Function ● High Frequency Compensation (f=10kHz, GV=+3dB) ● Variable Surround Effect by external resistor ● Internal Mode Control Switch ● Bipolar Technology ● Package Outline DMP24, SSOP24, SDIP30 ■ BLOCK DIAGRAM (DMP24, SSOP24) 24 22 20 21 19 18 17 16 15 14 13 50K 23 L HP SW 50K H 50K Vref H 3D FILTER LPF SW SW H:eala L:BYPASS L H VC SW H:eala_Bass L:BYPASS SW L HP 50K H 1 SW L 2 3 4 5 6 7 8 9 10 11 12 -1- NJM2706 ■ PIN CONFIGURATION DMP24, SSOP24 (Top View) 1 24 2 23 3 22 4 21 5 20 6 19 7 18 8 17 9 16 10 15 11 14 12 13 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. LPF MIN MOUT Ca Cr BASSFIL1 BASSFIL2 BASSVRIN BASSVROUT ealaVRIN ealaVROUT GND 13. V+ 14. VREFOUT 15. VREFIN 16. SW1 17. SW2 18. ealaFIL 19. HFFILL 20. HFFILR 21. ROUT 22. LOUT 23. RIN 24. LIN SDIP30 (Top View) -2- 1 30 2 29 3 28 4 27 5 26 6 25 7 24 8 23 9 22 10 21 11 20 12 19 13 18 14 17 15 16 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. LPF MIN N.C. MOUT Ca Cr BASSFIL1 N.C. BASSFIL2 BASSVRIN BASSVROUT ealaVRIN N.C. ealaVROUT GND 16. V+ 17. VREFOUT 18. N.C. 19. VREFIN 20. SW1 21. SW2 22. ealaFIL 23. N.C. 24. HFFILL 25. HFFILR 26. ROUT 27. LOUT 28. N.C. 29. RIN 30. LIN NJM2706 ■ABSOLUTE MAXIMUM RATING (Ta=25°C) PARAMETER SYMBOL Supply Voltage V RATINGS UNIT + 15 V (SDIP30) 700 (DMP24) 700 (SSOP24) 600 mW Power Dissipation PD Operating Temperature Range Topr -40 to +85 °C Storage Temperature Range Tstg -40 to +125 °C ■OPERATING VOLTAGE PARAMETER Operating Voltage SYMBOL TEST CONDITION MIN TYP MAX UNIT V+ - 4.7 12.0 13.0 V MIN TYP MAX UNIT ■ELECTRICAL CHARACTERISTICS (Ta=25°C, V+=12V unless otherwise specified) TEST CONDITION PARAMETER Operating Current Reference Voltage INPUT SYMBOL ICC Vref No Signal No Signal OUT MODE eala Bass L R PUT VR VR 0 0 - Bypass - - - 15.4 23.0 0 0 - Bass MAX - - 15.4 23.0 0 0 - - - - 5.8 6.0 6.2 V UNIT mA + ●AC CHARACTERISTICS (Ta=25°C, V =12V, VIN=-20dBV(100mVrms) unless otherwise specified) TEST CONDITION PARAMETER Maximum Input Voltage Output Noise Total Harmonic Distortion VIM VNO THD MIN TYP MAX - 10.0 (3.2) 12.0 (4.0) - MAX - - 6.0 (2.0) - eala - MAX - 7.9 (2.5) - L R eala Bass MAX MAX 7.8 (2.5) 9.8 (3.1) - VIN L R eala Bass MAX MAX 3.4 (1.5) 5.4 (1.9) - 0 0 L R Bypass - - - -110 (3) -100 (10) 0 0 L R Bass MAX - - -98 (13) - eala - MAX - -100 (10) - INPUT SYMBOL eala Bass VR VR Bypass - *1 Bass VIN L R VIN - VIN f=100Hz THD=3% VIN - Rg=0Ω A-Weighted Rg=0Ω A-Weighted OUT L R PUT f=1kHz THD=3% VIN - VIN L R f=100Hz THD=3% VIN VIN f=1kHz THD=3% VIN - f=10kHz THD=3% MODE Rg=0Ω A-Weighted 0 0 L R Rg=0Ω A-Weighted 0 0 L R eala Bass MAX MAX - -97 (14) -92 (25) f=1kHz VIN - VIN L R Bypass - - - 0.005 0.01 f=100Hz VIN VIN VIN VIN L R Bass MAX - - 0.05 - f=1kHz VIIN - VIN L R eala - MAX - 0.05 - f=1kHz VIN - VIN L R eala Bass MAX MAX - 0.05 0.5 dBV (Vrms) dBV (µVrms) % *1:BASSVR2OUT -3- NJM2706 + ●AC CHARACTERISTICS (Ta=25°C, V =12V, VIN=-20dBV(100mVrms) unless otherwise specified) TEST CONDITION PARAMETER SYMBOL Bypass Gain GVBYP eala Gain Geala INPUT OUT MODE eala Bass VR VR MIN TYP MAX UNIT dB L R PUT f=1kHz VIN - VIN L R Bypass - - -1.0 0.0 1.0 f=100Hz VIN VIN VIN VIN L R Bass MAX - 4.4 6.4 8.4 f=100Hz VIN VIN VIN VIN L R Bass MIN - -2.0 0.0 2.0 f=1kHz VIN - VIN L R eala - MAX 2.1 4.1 6.1 f=1kHz VIN - VIN L R eala - MIN -2.0 0.0 2.0 f=100Hz VIN - VIN L R eala Bass MAX MAX 5.9 7.9 9.9 f=10kHz VIN - VIN L R eala Bass MAX MAX 0.0 2.0 4.0 MIN TYP MAX dB + ●CONTROL CHARACTERISTICS (Ta=25°C, V =12V, unless otherwise specified) PARAMETER MODE Select Control Voltage TEST CONDITION SYMBOL VMODE VIN=High Level 2.0 - V VIN=Low Level 0.0 - 0.7 ■SWITCH FUNCTION MODE SW2 SW1 Bypass eala Bass eala Bass L L H H L H L H -4- NOTES Input Through 3D Surround mode Bass Enhanced mode 3D Surround and Bass Enhanced mode UNIT + V NJM2706 TERMINAL DESCRIPTION No. DMP24 SSOP24 SYMBOL FUNCTION EQUIVALENT CIRCUIT 1 LPF V+ 16k V+ 1 VOLTAGE SDIP30 Capacitor terminal for LPF V+/2 150 V+ 2 MIN V+ 20k 2 V+ Monaural Amplifier Input V+/2 150 4 MOUT 50 V+/2 Monaural Amplifier Output 50 3 10k V+ 16k V+ V+ 5 6 Ca Cr Capacitor Terminal for Attack Time Constant Capacitor Terminal for Release Time Constant 0V 100 10k 4 5 V+ V+ V+ V+ 6 7 BASSFIL1 82k 10k VCA 0V BASS Filter Terminal 1 150 -5- NJM2706 TERMINAL DESCRIPTION No. DMP24 SSOP24 SYMBOL FUNCTION EQUIVALENT CIRCUIT V+ BASSFIL2 ROUT LOUT BASS Filter Terminal 2 Rch Output Lch Output 50 9 26 27 V+ V+/2 50 7 21 22 V+ V+ 8 VOLTAGE SDIP30 10 BASSVRIN V+ BASS Effect Adjust Terminal V+/2 150 V+ V+ 20k V+ 9 11 BASSVROUT BASS Effect Adjust Terminal V+/2 150 V+ 20k V+ 10 12 ealaVRIN V+/2 eala Effect Adjust Terminal 150 14 ealaVROUT 50 V+/2 eala Effect Adjust Terminal 50 11 10k V+ 20k V+ -6- NJM2706 TERMINAL DESCRIPTION No. SYMBOL FUNCTION 15 GND GND Terminal 0V 16 V+ Power Supply Terminal V+ DMP24 SSOP24 SDIP30 12 13 EQUIVALENT CIRCUIT V+ V+ 50 V+ VOLTAGE 14 17 VREFOUT Reference Voltage Output V+/2 50 400 V+ 19 VREFIN Reference Voltage Input 50k 15 V+ 20 21 SW1 SW2 Mode Switch 1 Mode Switch 2 V+ V+/2 400 V+ 0V 150 150k 16 17 V+ 50k V+ -7- NJM2706 TERMINAL DESCRIPTION No. DMP24 SSOP24 SYMBOL FUNCTION EQUIVALENT CIRCUIT VOLTAGE SDIP30 V+ 32k V+ 18 22 ealaFIL eala Filter Terminal V+/2 10k V+ 15k V+ 19 20 24 25 HFFILL HFFILR High Frequency Filter for Lch High Frequency Filter for Rch V+/2 400 V+ 29 30 RIN LIN Rch Input Lch Input VREF -8- V+ V+/2 150 50k 23 24 V+ N.C. 10 20 20KB BassVR 11 6 7 8 9 10 11 12 13 19 18 17 14 100 µF 9 C17 8 12V 7 V+ 6 GND 5 10 µF BassVR GND V+ VREFOUT 14 VREFOUT 4 C5 3 N.C. ealaVRIN 2 ealaVROUT SW1 BASSVROUT 1 VREFIN SW2 BASSVRIN 15 1 µF 20KB Min ealaFIL BASSFIL2 16 VREFIN Max Min HFFILL BASSFIL1 17 10 µF C6 ealaSW BassSW Max 20K R2 0.18 µF HFFILR Cr 18 ealaVROUT ealaVRIN 21 SW1 10 µF R3 C7 10K C8 10K 0.0047 µF R4 30K 560pF C9 10 µF C4 ROUT Ca 19 Min BASSVROUT 5 SW2 C11 30K 560pF R5 C10 R6 1 µF C3 LOUT MOUT RIN MIN LIN LPF 20 Max BASSVRIN 4 22 Min 3 23 Max BASSFIL2 2 24 ealaFIL N.C. 1 25 20K R2 HFFILL BASSFIL1 26 N.C. HFFILR Cr 27 10 µF Rch Output C2 20K 0.1 µF R1 C1 21 0.18 µF ROUT Ca 10 µF C12 Lch Output Rch Input Lch Input 22 10 µF C4 LOUT MOUT C13 10 µF 10 µF C15 C16 23 1 µF C3 N.C. LIN N.C. 28 RIN 29 MIN 30 LPF 24 C2 20K 0.1µF R1 C1 C11 100 µF C17 12V 10 µF 1 µF C5 10 µF C6 10 µF R3 C7 10K C8 10K ealaSW BassSW Rch Output Lch Output Rch Input Lch Input 30K 560pF C9 0.0047 F µ R4 30K 560pF R5 C10 R6 10 µF 10 µF C12 10 µF C13 10 µF C15 C16 NJM2706 ■APPLICATION CIRCUIT (DMP24, SSOP24) 13 12 20KB ealaVR (SDIP30) 16 15 20KB ealaVR -9- NJM2706 ■APPLICATION NOTE 1. Fine-Tuning the ealaBASS The NJM2706 has quite sophisticated NJRC’s original dynamic bass-boost technology. Both of the level and the frequency for bass-boost moves automatically corresponding to the input signal level. This dynamic filtering action prevents the signals over boosted, and provides less distortion and wide dynamic range bass-boost processing. In addition, if you want to fine-tune the bass-boost effect for your system, you can modify the bass-boost effect by changing the external parts value as described below. 1-1. Modify the Boost Center Frequency This plot shows the frequency response for NJM2706 ealaBASS. Frequency Characteristics (eala Bass) V+=12V Vin=-20dBVLch Vout=Lch RL=4.7k Ω Rg=25Ω Ω 10 C4=0.1µF C4=0.15µF 5 Gain [dB] C4=0.18µF 0 -5 10 100 1000 10 4 10 5 Frequency [Hz] The Boost Center Frequency can be adjusted by changing the value for the external capacitor, C4. If your speaker system has more than 100Hz of f0 (= Lower Frequency Response Range), or, if you would like to get more powerful bass-boost effect than the typical settings shown on the page 9, increasing the Boost Center Frequency higher could be a good idea. We strongly recommend you to determine the actual capacitance value by testing and examinations on your actual application. 1-2. Modification for the LPF Cut-off Frequency fCL This picture shows the equivalent circuit for NJM2706’s LPF. R1 20k 20k 2pin Lch 3pin LPF 20k Rch 16k MONO Amp. 1pin C1 0.1µ * The pin numbers apply in DMP24 and SSOP24's case. The LPF Cut-off Frequency fCL is given by the following equation: 1 1 fCL= 2πCR = 2πC1×16k Set the fCL as same as the Boost Center Frequency, which is determined as above (The Boost Center Frequency = the frequency of which the gain is +3dB). In the typical application circuit shown on the page 9, the LPF Cut-off Frequency fCL is set to 100Hz. - 10 - NJM2706 1-3. Adjusting the Summing Level for ealaBASS effect to L/R Output Signal Changing the resistance value connected between the terminal 8 and 9 can modify the Summing Level for the ealaBASS effect to the L/R Output Signal. 2. Adjusting the High Frequency Compensation Filter The NJM2706 has High Frequency Compensation Filter, which can produce well balance between boosted–bass frequency range and treble frequency range. This picture shows the equivalent circuit for the High Frequency Compensation Filter. 15k 20pin HFFIL R6 30k C11 560p * The pin numbers apply in DMP24 and SSOP24's case. The Cut-off Frequency fCH and the Voltage Gain GVH are defined as below: fCH= 1 = 2πCR 1 2π×C11×R6 GVH= 20log R6+15k R6 In the typical application circuit shown on the page 9, the High Frequency Compensation Filter Cut-off Frequency fCH is set to 10kHz and Voltage Gain GVH is set to 3.5dB. - 11 - NJM2706 ■TYPICAL CHARACTERISTICS Supply Current vs. Supply Voltage Supply Current vs. Temperature V+=12V V+=1-13V, Ta=25 oC 16 20 BASS eala BASS Bypass 15 Supply Current [mA] Supply Current [mA] 15 BASS eala 10 Bypass 14 13 12 5 11 10 0 0 5 10 15 -50 20 0 Maximum Input Voltage vs. Supply Voltage (BASS) Vin=Lch+Rch, Vout=BASSVROUT, f=100Hz, RL=4.7k Ω , Vin=Lch, Vout=Lch, f=1kHz, RL=4.7k Ω , Rg=25Ω Ω , Ta=25 oC Rg=25Ω Ω , Ta=25 oC 20 20 15 15 Maximum Input Voltage [dBV] Maxmum Input Voltage [dBV] 150 Temperature [ C] Maximum Input Voltage vs. Supply Voltage (Bypass) 10 5 0 -5 10 5 0 -5 -10 -10 0 4 8 12 0 16 4 8 12 16 Supply Voltagte [V] Supply Voltage [V] Maximum Input Voltage vs. Supply Voltage (eala) Maximum Input Voltage (eala BASS) Vin=Lch, Vout=Lch, f=1kHz, RL=4.7k Ω , Vin=Lch, Vout=Lch, f=10kHz, RL=4.7k Ω , Rg=25Ω Ω , Ta=25 oC Rg=25Ω Ω , Ta=25 oC 15 15 10 10 Maximum Input Voltage [dBV] Maximum Input Voltage [dBV] 100 o Supply Voltage [V] 5 0 -5 5 0 -5 -10 -10 -15 -15 0 4 8 12 Supply Voltage [V] - 12 - 50 16 0 4 8 12 Supply Voltage [V] 16 NJM2706 ■ TYPICAL CHARACTERISTICS Maximum Input Voltage vs. Supply Voltage (eala BASS) Vin=Lch+Rch, Vout=Lch, f=100Hz, RL=4.7k Ω , Output Noise vs. Temperature V+=12V, Vin=GND, Vout=Lch 15 -90 10 -95 5 -100 Output Noise [dBV] Maximum Input Voltage [dBV] Rg=25Ω Ω Ta=25 oC 0 eala BASS BASS eala -105 -110 -5 Bypass -115 -10 -120 -15 0 4 8 12 -50 16 0 50 150 Temperature [ C] Supply Voltage [V] THD+N vs. Input Voltage (Bypass) THD+N vs. Input Voltage (Bypass) V+=12V, Vin=Lch, Vout=Lch, f=1kHz, RL=4.7k Ω , Rg=25Ω Ω , BW=10-80KHz V+=12V, Vin=Lch, Vout=Lch, f=100Hz, RL=4.7k Ω , Rg=25Ω Ω , BW=10-80kHz 10 100 o 10 1 1 Ta=85oC Ta=25oC 0.1 0.1 THD+N [%] THD+N [%] Ta=85oC Ta=-40oC 0.01 Ta=25oC Ta=-40oC 0.01 0.001 0.001 0.0001 0.0001 -50 -40 -30 -20 -10 0 10 -50 20 -40 -30 Input Voltage [dBV] -10 0 10 20 Input Voltage [dBV] THD+N vs. Input Voltage (eala) THD+N vs. Input Voltage (Bypass) V+=12V, Vin=Lch, Vout=Lch, f=1kHz, RL=4.7k Ω , Rg=25Ω Ω , BW=10-80kHz V+=12V, Vin=Lch, Vout=Lch, f=10kHz, RL=4.7k Ω , Rg=25Ω Ω , BW=10-80kHz 10 -20 10 1 Ta=-40oC THD+N [%] THD+N [%] 1 Ta=85oC 0.1 o Ta=25 C Ta=25oC Ta=85oC Ta=-40oC 0.1 0.01 0.001 0.01 -50 -40 -30 -20 -10 Input Voltage [dBV] 0 10 20 -50 -40 -30 -20 -10 0 10 20 Input Voltage [dBV] - 13 - NJM2706 ■ TYPICAL CHARACTERISTICS THD+N vs. Input Voltage (eala BASS) THD+N vs. Input Voltage (eala BASS) V+=12V, Vin=Lch, Vout=Lch, f=100Hz, RL=4.7k Ω , Rg=25Ω Ω, BW=10-80kHz V+=12V, Vin=Lch, Vout=Lch, f=1kHz, RL=4.7k Ω , Rg=25Ω Ω , BW=10-80kHz 10 10 1 THD+N [%] THD+N [%] 1 o Ta=85 C Ta=25oC Ta=-40oC 0.1 Ta=-40oC Ta=25oC Ta=85oC 0.1 0.01 0.01 -50 -40 -30 -20 -10 0 10 20 -50 -40 -30 Input Voltage [dBV] -20 -10 0 10 20 Input Voltage [dBV] THD+N vs. Input Voltage (eala BASS) Gain vs. Frequency (Bypass) V+=12V, Vin=Lch, Vout=Lch, f=20kHz, RL=4.7k Ω , Rg=25Ω Ω , BW=10-80kHz V+=12V, Vin=-20dBV Lch, Vout=Lch, RL=4.7k Ω , Rg=25Ω Ω 3 10 2 Ta=85oC 1 Ta=25oC 1 Gain [dB] THD+N [%] Ta=-40oC Ta=-40oC Ta=25oC Ta=85oC 0.1 0 -1 -2 0.01 -3 -50 -40 -30 -20 -10 0 10 20 10 100 Input Voltage [dBV] Gain vs. Frequency (BASS) 10 10 8 Gain [dB] Gain [dB] Ta=-40oC 4 6 2 0 0 10 4 10 5 5 Ta=25oC Ta=-40oC 4 2 -2 - 14 - 10 Ta=85oC Ta=25oC Frequency [Hz] 5 8 Ta=85oC 1000 10 Gain vs. Frequency (eala) 12 100 4 V+=12V, Vin=-20dBV Lch, Vout=Lch, RL=4.7k Ω, Rg=25Ω Ω 12 10 10 Frequency [Hz] V+=12V, Vin=-20dBV Lch+Rch, Vout=Lch, RL=4.7k Ω, Rg=25Ω Ω 6 1000 -2 10 100 1000 Frequency [Hz] 10 4 NJM2706 ■ TYPICAL CHARACTERISTICS Gain vs. Frequency (eala BASS) V+=12V, Vin=-20dBV Lch, Vout=Lch, RL=4.7k Ω, Rg=25Ω Ω Gain vs. Frequency (eala BASS) 20 12 10 15 Ta=85oC 8 Ta=25oC -40dBV INPUT -30dBV INPUT 10 6 Gain [dB] Gain [dB] Ta=-40oC 4 -20dBV INPUT -10dBV INPUT 5 0dBV INPUT 2 0 0 -5 -2 10 100 1000 10 4 10 5 10 100 1000 10 4 Frequency [Hz] Frequency [Hz] [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. - 15 -