NJU Vrms Ground Referenced Stereo Line Amplifier PACKAGE OUTLINE

Transcription

1 NJU rms Ground Referenced Stereo Line Amplifier GENERAL DESCRIPTION The NJU is an audio line Amplifier. It can swing rms (. peak-to-peak) signal at. operating voltage. Ground-referenced outputs eliminate output coupling capacitor. It contains differential input. The pop noise suppression circuit removes a pop noise at the power-on and power-off. PACKAGE INE NJU APPLICATIONS Audio applications requiring rms outputs FEATURES Operating oltage Operating Current Output Coupling Capacitor-less Differential Input Pop Noise Suppression Circuit C-MOS Technology Package Outline BLOCK DIAGRAM ufkω +. to +. I DD =ma typ.at =., No Signal, No Load SSOP kω uf PIN CONFIGURATION ufkω kω uf OUTR Active Mute uf oltage Detector UP No. Symbol Function Lch Noninverted Input Lch Inverted Input Lch Output GND Ground Mute Control Power Supply Flying Capacitor Negative Terminal uf Flying Capacitor Positive Terminal Power Supply Ground UP Undervoltage Protection Input OUTR Rch Output Rch Inverted Input Rch Noninverted Input er..e

2 NJU ABSOLUTE MAXIMUM RATING (Ta= C) PARAMETER SYMBOL RATING UNIT Supply oltage + Power Dissipation P D (Note)) mw Maximum Input oltage IMAX - -. ~ +. Operating Temperature Range Topr - ~ + C Storage Temperature Range Tstg - ~ + C (Note) EIA/JEDEC STANDARD Test board (.x.x.mm, layer, FR-) mounting RECOMMENDED OPERATING CONDITIONS ( =., Ta= C unless otherwise specified) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Operating oltage... ELECTRICAL CHARACTERISTICS DC CHARACTERISTICS ( =., Mute=OFF, R L =kω Ta= C unless otherwise specified) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Operating Current I DD No signal, No load - ma Power Supply Rejection Ratio PSRR = to. - - db External undervoltage detection uvp -. - External undervoltage detection hysteresis current I Hys - - ua Output Offset oltage OS Rg=Ω - - m AC CHARACTERISTICS ( =., f=khz, in=rms [differential input], Mute=OFF, =kω, R fb =, R L =kω Ta= C unless otherwise specified) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Maximum Output oltage Level OMAX THD=% -. - rms Mute Level Rg=Ω, Mute=ON db Equivalent Input Noise oltage NI Rg=Ω, A-weighted db Total Harmonic Distortion THD BW:Hz-kHz -. - % Channel Separation CS Rg=Ω, Bandpass - - db CONTROL CHARACTERISTICS ( =., Ta= C unless otherwise specified) PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Mute terminal High MuteH Mute=OFF. - Mute terminal Low MuteL Mute=ON -.

3 NJU TEST CIRCUIT I DD PSRR uf kω kω uf uf kω kω uf OUTR R L =kω OUTR R L =kω oltage Detector UP oltage Detector UP uf A uf uf uf UP, I Hys, OMAX, OS ufkω p Inverted Phase ufkω n kω uf kω uf p n uf uf kω kω kω uf kω uf OUTR R L =kω R L =kω R L =kω OUTR R L =kω Active oltage Detector UP A oltage Detector UP Mute uf uf uf uf

4 NJU NI NI = Measurement - db THD uf kω uf kω kω uf uf kω ufkω p Inverted Phase ufkω n kω uf kω uf p n Inverted Phase Filter OUTR Filter Filter OUTR Filter R L =kω oltage Detector UP R L =kω R L =kω oltage Detector UP R L =kω uf uf uf uf CS : CS = *Log(OUTR/) OUTR: CS = *Log(/OUTR) Inverted Phase Ω Ω uf kω p uf kω n kω uf p kω uf n Ω Ω Inverted Phase R L =kω OUTR R L =kω oltage Detector UP Active Mute uf uf

5 NJU APPLICATION CIRCUIT C IN C IN C IN C IN OUTR oltage Detector UP R R Active R Mute C D uf C FLY *) Connect a zener diode between terminal and GND terminal to prevent connecting terminal[pin] and terminal[pin].

6 NJU APPLICATION NOTES Technical Information Operating Overview The drawing in Fig illustrates the internal circuit in NJU. The NJU has a charge-pump for negative power supply, pop noise suppression circuit, external under voltage detector, and a line amplifier. The NJU operates from a single supply voltage from. to. and the NJU s line drivers use a charge pump to invert the positive power supply () to negative power supply (), see Fig. The output voltages are centered at zero volts with the capability to swing to the positive rail or negative rail. This feature eliminates the output capacitor that is using in conventional line driver operating by a single-supply voltage. Gain Setting Resistor The drawing in Fig. illustrates the gain setting circuit configuration of NJU. The differential input gain of the NJU is set by: R A R FB IN The value of Gain setting resistors, and, affect noise, stability and input capacitor size. Selecting values that are too low demands a large input ac-coupling capacitor, C IN. Selecting values that are too high increases the noise of the amplifier. C IN C I N A GND oltage Detector OUTR U P R C IN C IN R Input Coupling Capacitor An input capacitor, C IN, is required to be added in series with the audio signal into the input pins of the NJU. The capacitor allows the amplifier to bias the input signal to the proper DC level for optimum operation. These capacitors form a high-pass filter with the input resistor,. The cutoff frequency is set by: A c tiv e Mute R f C(HPF) R C IN IN C - D - uf The value of C IN must be considered carefully because it directly affects the low frequency response and can distort the audio signal. C FL Y Fig. NJU Block diagram OUT OUT / GN D GND Conventional Line Driver NJU Fig. Capacitor-free Operation

7 Flying Capacitor The flying capacitor is required to generate a negative power supply. To achieve a high efficiency, low-esr capacitors (ceramic capacitor) are to be selected, and to be placed near the terminal (pin) and terminal (pin) so as to reduce the resistance caused by the PCB trace. The recommended value of this capacitor is uf. Selecting values that are too low might reduce the maximum output voltage and might not be operated to specifications. C FLY Fig. Flying pin/pin Negative supply decoupling Capacitor To achieve a high efficiency on the negative voltage regulator (negative supply for the amplifier circuit), low ESR capacitor (ceramic capacitor) is to be used for this decoupling capacitor. This capacitor is to be placed near the - terminal (pin) so as to reduce the resistance caused by the PCB trace. The recommended value of this capacitor is uf. Application Circuit for Using UP NJU Technical Information oltage Protection External under voltage detection can be used to mute the NJU s output before an input device can generate a pop noise. The active-mute threshold at the UP pin is.. The user selects a resistor divider to obtain the active-mute threshold and hysteresis for the specific application. The threshold is set by: HYS UP R R R R. R R (. R R HYS R R ) R with the condition R >> R //R For example, to obtain UP = and hysteresis, R =kω, R =kω and R =kω. If the UP function is not used, A pull-up resistance,r PULL is to be connected between UP terminal and terminal. Sy stem Power C UP R R R Fig. Decoupling pin Application Circuit for Not Using UP Protection Diode For protection purpose, it is advisable to place a low f diode (Schottky diode) to Ground at - terminal (pin ). The external diodes will protect the IC negative supply terminal when a positive voltage is accidentally applied to the pin. R PULL >kω UP Sequence of UP Function C D Output Active HYS Fig. Negative supply pin Mute UP UP + HYS Fig. UP function System Power

8 NJU Power up & down sequence to minimize pop noise Technical Information To further reduce pop noise, Recommend to Fig. how Power up and down sequence. When power supply is turned ON To further reduce pop noise during power ON, the terminal should switch L->H after the power supply terminal has turned ON. It is recommended to have a time interval of msec (T ON ) or more between these two transitions. When power supply is turned OFF To further reduce pop noise during power OFF, the terminal should switch H->L after the power supply terminal has turned OFF. It is recommended to have a time interval of msec (T OFF ) or more between these two transitions. Positiv e Power Supply [pin] T ON>msec Mute [pin] TOFF>msec Fig. Timing diagram when turning on power supply and intercepting it

9 NJU TERMINAL DESCRIPTION Terminal SYMBOL FUNCTION EQUIALENT CIRCUIT OLTAGE AC Input OUTR AC Output Ω GND Control kω kω GND Flying Capacitor Negative Terminal Flying Capacitor Positive Terminal Ground - - er..e

10 NJU TERMINAL DESCRIPTION Terminal SYMBOL FUNCTION EQUIALENT CIRCUIT OLTAGE UP Undervoltage Protection Input Ω - GND

11 NJU TYPICAL CHARACTERISTICS IDD vs Supply oltage No Signal, No Load IDD vs Supply oltage No Signal, No Load DD= to DD= to IDD [ma] IDD [ma] -/ o C - o C o C / o C o C Supply oltage [] o C..... Supply oltage [] IDD vs Tempreature No Signal, No Load - SS vs Tempreature No Signal, No Load =. -. =. =. IDD [ma] =. =. SS [] - -. =. - Temperature [ O C] - - Temperature [ O C] PSRR vs Tempreature = to. PSRR vs Frequency =., ripple=mrms, RL=kΩ, Bandpass o C o C - - SS [] - PSRR [db] / o C Temperature [ O C] Frequency [Hz]

12 NJU TYPICAL CHARACTERISTICS - - UP Control =/./.,IN=rms[differential], f=khz, RL=kΩ, R=kΩ, R=kΩ, R=kΩ, Ta= o C UP ON - - UP Control =.,IN=rms[differential], f=khz, RL=kΩ, R=kΩ, R=kΩ, R=kΩ, Ta=-/// o C UP ON - o C oltage Gain [db] =/./. oltage Gain [db] o C // o C // o C UP OFF - UP OFF - UP Input [] - UP Input [] UP Control =/./., IN =rms[differential], f=khz, R L =kω R=kΩ, R=kΩ, R=kΩ, Ta= o C UP Control =., IN =rms[differential], f=khz, R L =kω R=kΩ, R=kΩ, R=kΩ, Ta=-/// o C UP ON UP ON // o C I HYS [ua] =/./. I HYS [ua] - o C - o C // o C UP OFF UP Input [] UP OFF UP Input [] Maximum Output oltage vs Supply oltage f=khz, THD=%, R L =kω. Maximum Output oltage vs Frequency =., THD=%, R L =kω Maximum Output oltage [rms].... -/// o C Maximum Output oltage [rms] / o C / o C... Supply oltage [] k k k Frequency [Hz]

13 NJU TYPICAL CHARACTERISTICS. Maximum Output oltage vs Temperature =., f=khz, THD=%, R L =kω - vs Temperature =., f=khz, =Gv [] /Gv [ACTIE],.A-w eighted - Maximum Output oltage [rms]... Lch/Rch [db] Lch / Rch -. - Temperature [ O C] - - Temperature [ O C] Mute Control =/./., IN =rms[differential], f=khz, R L =kω Ta= o C Mute Control =., IN =rms[differential], f=khz, R L =kω Ta=-/// o C oltage Gain [db] ACTIE ACTIE oltage Gain [db] ACTIE ACTIE = =. =. - - / o C o C - o C Mute Terminal [x ] Mute Terminal [] - NI vs Temperature =., Rg=Ω, A-w eighted THD+N vs Temperature =.,, IN =rms[differential], f=khz, RL=kΩ, BW:-kHz - Lch NI [db] - Rch THD+N [%]_.. Lch/Rch Temperature [ O C]. - Temperature [ O C]

14 NJU TYPICAL CHARACTERISTICS THD+N vs Output oltage =., BW:-kHz(f=/kHz), -khz(f=khz) THD+N vs Output oltage =., f=hz, BW:-kHz, R L =kω THD+N [%].. f=khz THD+N [%].. -/// o C. f=hz f=khz... Output oltage [rms].... Output oltage [rms] THD+N vs Output oltage =., f=khz, BW:-kHz, R L =kω THD+N vs Output oltage =., f=khz, BW:-kHz, R L =kω THD+N [%].. -/// o C THD+N [%].. -/// o C..... Output oltage [rms]... Output oltage [rms] THD+N vs Frequency =., o=.rms, BW:-kHz THD+N vs Frequency =., o=.rms, BW:-kHz THD+N [%].. / o C THD+N [%].. o C o C. -/ o C. Frequency [Hz]. - o C o C. Frequency [Hz]

15 NJU TYPICAL CHARACTERISTICS Channel Separation vs Frequency =., O =rms, R g =Ω, BW:BandPass, R L =kω Channel Separation vs Frequency =., O =rms, R g =Ω, BW:BandPass, R L =kω Lin - Rout -/// o C Channel Separation [db] Rin - Lout Channel Separation [db] Frequency [Hz] Frequency [Hz] Output oltage vs Load Resistance =., f=khz, THD=% Negative Supply oltage vs Load Current =., No Signal, No Load -. Output oltage [rms].. -/// o C Negative Supplyt oltage [rms] o C o C o C - o C k k k Load Resistance [Ω] -. Load Current [ma] [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.