NJM2171A LOW VOLTAGE HEADPHONE AMPLIFIER for PORTABLE AUDIO ■ GENERAL DESCRIPTION The NJM2171A is a low voltage headphone amplifier designed for portable audio items. The NJM2171A operates directly for battery supply. It includes mute and standby circuit which require few external components and realize low current consumption and very low turn-noise at standby mode. It is suitable for portable Mini-Disc, portable Compact-Disc, and other headphone amplifier application. ■ FEATURES ● Operating Voltage ■ PACKAGE OUTLINE NJM2171AR + V 1=1.8 to 4.5V + V 2=0.9 to 4.5V + ● Operating Current 450µA typ. @V 1=2.3V + 700µA typ. @V 2=1.2V ● Supply Current in Power Down Mode + 10µA typ. @V 1=2.3V + 25µA typ. @V 2=1.2V @THD=10% ● Output Power Exceeds 5mW RL=16Ω ● Fixed Voltage Gain 11.5dB typ. ● Package Outline VSP10 ● Bipolar Technology ■ PIN CONFIGURATION 1 2 10 AMP1 AMP2 8 3 4 5 9 MUTE BIAS 7 6 PIN FUNCTION + 1.V 2 2.OUT1 3.IN1 4.STBY + 5.V 1 6.VREF 7.MUTE 8.IN2 9.OUT2 10.GND NJM2171A ■ ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL + Supply Voltage V Power Dissipation PD Operating Temperature Range Topr Storage Temperature Range Tstg RATINGS 5 (VSP8) 320 -20 to +75 -40 to +125 ■ RECOMMENDED OPERATING CONDITIONS PARAMETER SYMBOL MIN. + Operating Voltage Range1 V1 1.8 + Operating Voltage Range2 V2 0.9 + TYP. 2.3 1.2 MAX. 4.5 4.5 (Ta=25°C) UNIT V mW °C °C (Ta=25°C) UNIT V V + ■ ELECTRICAL CHARACTERISTICS (V 1=2.3V,V 2=1.2V,Rg=600Ω,RL=16Ω,f=1kHz,Ta=25°C) PARAMEETER SYMBOL TEST CONDITION MIN. TYP. + ICC0 V 1=0V(1pin) ICC1 STANDBY ON,MUTE ON(1pin) 25 ICC2 STANDBY ON,MUTE ON(5pin) 10 Operating Current ICC3 No signal(1pin) 700 ICC4 No signal(5pin) 450 ICC5 PO=0.5mW+0.5mW(1pin) 5.5 ICC6 PO=0.5mW+0.5mW(5pin) 0.8 Reference Voltage VREF No signal 0.55 0.60 Closed Loop Gain GV VIN=-30dBV 10.5 11.5 PO1 THD=10% 5.0 8.5 Output Power + + V 1=1.8V,V 2=0.9V,THD=10% 2.0 4.0 PO2 0.15 THD1 Po=1mW,RL=16Ω Total Harmonic Distortion 0.4 TED2 Po=5mW,RL=16Ω Output Noise Voltage VNO A-Weighted -100 Crosstalk CT VIN=-30dBV -80 Mute Level MUTE MUTE-ON,VIN=-30dBV,A-Weighted -95 + + V 1=1.8V+0.1Vrms, V 2=0.9V 60 70 Supply Voltage Rejection SVR1 + + Ratio SVR2 V 1=1.8V, V 2=0.9V+0.1Vrms 60 70 MAX. 1 40 15 1200 700 0.65 12.5 0.3 0.6 -96 -70 -80 - UNIT µA mA V dB mW % dBV dBV dBV dB NJM2171A ■ CONTROL TERMINAL CHARACTERISTICS PARAMETER SYMBOL TEST CONDITION High Level Input Voltage VIH STBY(4pin), MUTE(7pin) Low Level Input Voltage VIL STBY(4pin), MUTE(7pin) ■ CONTROL TERMINAL EXPLANATION •STBY (4Pin) PARAMETER CONTROL SIGNAL STANDBY ON H IC is non-active. STANDBY OFF L IC is active. •MUTE (7Pin) PARAMETER MUTE ON MUTE OFF MIN. 1.2 0 TYP. - MAX. + V1 0.3 UNIT V V STATUS CONTROL SIGNAL STATUS H IC doesn’t output the signal. L IC output the signal. ■ APPLICATION CIRCUIT 10 1 V+2 22µF 330µF 330µF 2 OUT1 16Ω AMP1 AMP2 STBY OFF V+1 100kΩ 4 MUTE 1µF 5 22µF 16Ω 8 3 STBY ON OUT2 0.47µF 0.47µF IN1 9 BIAS 7 IN2 100kΩ MUTE ON 1µF MUTE OFF 6 22µF [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.