NJM2795

NJM2795 Ground noise isolation Amplifier with Adjustable Differential Gain GENERAL DESCRIPTION The NJM2795 is a ground noise isolation amplifier. It contains dual channel differential amplifier with Adjustable Differential Gain. It is developed for those car audio applications where long connections between head unit and other components are necessary and ground noise has to be eliminated. Further the NJM2795 allow the user to alter the gain to optimize the signal-to-noise ratio of their system. It is useful in microphone amplifier applications. PACKAGE OUTLINE NJM2795V FEATURES l Dual Channel Differential Amplifier l Adjustable Differential Gain +6dB to +52dB l Operating Voltage 4.3 to 20V l Operating Current 7mA typ. l Maximum Output Voltage 2Vrms min., @ THD=1% l Common mode rejection ratio80dB typ. l Supply Voltage Rejection Ratio 65dB typ. l Total Harmonic Distortion 0.005% typ. l Equivalent Input Noise Voltage 2µVrms typ. @ Gv=+20dB l Bipolar Technology l Package Outline SSOP14 BLOCK DIAGRAM V+ RG1IN1OUT1 IN1+ RG1+ VREF RG2+ IN2+ OUT2 IN2RG2GND Ver .2.2E –1– PIN CONFIGURATION No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Symbol OUT1 RG1+ GND VREF V+ RG2+ OUT2 IN2+ RG2IN2NC IN1RG1IN1+ Function Output1 Gain Ajustment 1+ Ground Reference Voltage Power Supply Gain Ajustment 2+ Output2 +Input2 Gain Ajustment 2-Input2 No Connect -Input1 Gain Ajustment 1+Input1 1 14 7 8 –2– Ver .2.2E NJM2795 ABSOLUTE MAXIMUM RANGES (Ta=25°C) PARAMETER Supply Voltage Maximum Input Voltage SYMBOL V + RANGE +22 0 to V SSOP14 : 555* NOTE: EIA/JEDEC STANDARD Test board (76.2x114.3x1.6mm, 2layer, FR-4) mounting +( ) UNIT V V VIM Power Dissipation Operating Temperature Storage Temperature PD Topr Tstg mW °C °C -40 to +85 -40 to +150 ( ) For the maximum input voltage less than 0 toV + ELECTRICAL CHARACTERRISTIC (V+=9V, Ta=25°C) PARAMETER DC CHARACTERRISTIC Operating Voltage Operating Current Reference Voltage V+ ICC VREF SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT 4.3 No Signal 4.0 9 7 4.5 20 10 5.0 V mA V AC CHARACTERRISTIC (Non-inverting circuit, f=1kHz, Vin=100mVrms, Rg=0Ω, RG=10kΩ, RL=10kΩ unless otherwise specified) GV1 Voltage Gain 1 RG=91kΩ +4.0 +6.0 +8.0 Voltage Gain 2 Voltage Gain 3 Channel Separation Channel Balance Roll-off High Frequency Input Resistance Output Resistance Maximum Output Voltage 1 Maximum Output Voltage 2 Equivalent Input Noise Voltage Total Harmonic Distortion Common Mode Rejection Ratio (*) Supply Voltage Rejection Ratio Note (*): GV2 GV3 CS BAL fRH RIN ROUT VOM1 VOM2 VNI THD CMRR SVR dB dB dB dB dB kHz kΩ Ω Vrms Vrms µVrms % dB dB RG=10kΩ RG=220Ω, Vin=2.5Vrms VO=2Vrms, A-weighted -3dB +18.0 +50.0 90 100 160 - +20.0 +52.0 100 200 200 2.5 2.5 2 0.005 80 65 +22.0 +54.0 0.5 240 3 0.05 - THD=1% Inverting, THD=1% Rg=600Ω, A-weighted, Gv=+20dB VO=1Vrms, BW=400Hz to 30kHz VICM=1Vrms 2 70 55 f=100Hz , Vripple=100mVrms CMRR = GV 2 , Where GV 2 is the Differential Mode Gain and GVCM is the Common Mode Gain. GVCM ⎛V GVCM = 20 * log⎜ OCM ⎜V ⎝ ICM ⎞ ⎟ , Where VOCM is the Common Mode Output and V ICM is the Common Mode Input. ⎟ ⎠ Ver .2.2E –3– TERMINAL DESCRIPTION PIN NO. SYMBOL FUNCTION EQUIVALENT CIRCUIT TERMINAL DC VOLTAGE V+ 1 7 OUT1 OUT2 Output1 Output2 V+ V+ 200Ω V x 0.5 + V+ 2 6 9 13 RG1RG2RG2+ RG1+ Gain Adjustment 1Gain Adjustment 2Gain Adjustment 2+ Gain Adjustment 1+ V+ 750Ω V x 0.5 + 200k Ω V+ 8 10 12 14 IN2+ IN2IN1IN1+ +Input2 -Input2 -Input1 +Input1 V+ V+ 750Ω V x 0.5 + 45k Ω V+ V+ V+ 4 VREF Reference Voltage 240k Ω 750Ω V x 0.5 + 240k Ω –4– Ver .2.2E NJM2795 APPLICATION CIRCUIT RG OUT1 3.3µF + 1 RG12 GND 3 22µF + 200kΩ 200kΩ 14 RG1+ 13 1µF + IN1+ 12 NC 11 1µF + IN1- VREF 4 V+ 200kΩ + 47µF 5 RG26 200kΩ 10 1µF + IN2- RG2+ 9 1µF + OUT2 3.3µ F + IN2+ 7 8 RG Ver .2.2E –5– APPLICATION BLOCK DIAGRAM (1) Non-inverting line input IN+ OUT NJM2795 INIC GND Vref VN (2) Inverting line input INOUT NJM2795 IN+ IC GND Vref VN (3) Non-inverting line output IN+ OUT NJM2795 INIC GND Vref VN (4) Inverting line output INOUT NJM2795 IN+ IC GND Vref VN [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. –6– Ver .2.2E