NJM2781 Monaural Microphone Amplifier ■ PACKAGE OUTLINE ■ GENERAL DESCRIPTION NJM2781 is a monaural microphone amplifier IC with a standby function, and can vary a voltage gain by adjusting an external resistor. Since the NJM2781 operates with a low voltage range of +2.7V to +4.5V and is available in tiny packages of TVSP8 and SSOP8, it is ideally suited for portable and handheld components. NJM2781RB1 NJM2781V ■ FEATURES ● Operating Voltage ● Operating Current +2.7V to +4.5 V 1.8mA typ. 1µA max. (in Standby mode) ● Bipolar Technology ● Package Outline TVSP8, SSOP8 ■ BLOCK DIAGRAM NOISE 1 GND 8 V+ 7 REG 2 Reg STBY OUT 3 4 IN- IN+ 6 5 ■ PIN FUNCTION 1 4 8 5 No. SYMBOL FUNCTION No. SYMBOL FUNCTION 1 NOISE Noise Bypass 5 IN- Inverted Input 2 REG Regulator Output 6 OUT Output 3 STBY Standby On/Off 7 V+ Power Supply 4 IN+ Non-Inverted Input 8 GND Ground –1– NJM2781 ■ ABSOLUTE MAXIMUM RATING (Ta=25°°C) PARAMETER SYMBOL + RATING UNIT Supply Voltage V 5 V Power Dissipation PD TVSP8:320, SSOP8:250 mW Operating Temperature Range Topr -40 to 85 °C Storage Temperature Range Tstg -40 to 125 °C ■ ELECTRICAL CHARACTERISTICS + (Ta=25°C,V =2.8V,Vin=-40dBV, f=1kHz,RL=9kΩ) ●Power Supply PARAMETER SYMBOL TEST CONDITION Operating Voltage V Operating Current 1 Icc1 No signal, Standby Operating Current 2 Icc2 No signal, Active Mic Power Supply Voltage Vo + RL=6.8kΩ MIN. TYP. MAX. UNIT 2.7 2.8 4.5 V - 1 µA 1.8 4 mA 2.3 2.42 2.54 V MIN. TYP. MAX. UNIT 1.28 1.35 1.42 V 24 -2.7 (0.73) 25 -1.5 (0.84) 26 dB dBV (Vrms) - 0.025 0.1 % - -98 (12.6) -90 (31.6) dBV (µVrms) 65 80 - dB MIN. TYP. MAX. UNIT ●Amplifier PARAMETER SYMBOL Output Voltage Vo Voltage Gain GV Test Circuit 1 Maximum Output Voltage VOM THD=0.1% Total Harmonic Distortion (THD+N) THD Output Noise VNO Power Supply Ripple Rejection ●Control PARAMETER PSRR SYMBOL TEST CONDITION Rg=600Ω, A-Weighted Rg=600Ω, Vripple=-20dBV TEST CONDITION - + High Level Input Voltage VIH STBY terminal 2 - V V Low Level Input Voltage VIL STBY terminal 0 - 0.5 V ■Standby Mode Operation –2– Status Control Terminal STBY IC Condition Active H IC active Standby L, OPEN IC standby NJM2781 ■ TEST CIRCUIT Test Circuit 1 (Voltage Gain Gv, Maximum Output Voltage VOM, Total Harmonic Distortion THD) 1µF 8 GND V+ 7 V+ 3 OUT 6 4 IN- 5 REG 10µF 2 100Ω 10µF Input 6.8kΩ V+ NOISE GND 1 Reg STBY IN+ 0.33µF 2.2µF 47kΩ 15kΩ Output 9kΩ [THD] BPF:400 to 22kHz 4.7µF 680Ω Test Circuit 2 (DC Output Voltage VO, Output Noise VNO) 1µF 1 REG 10µF 2 100Ω 10µF Input NOISE STBY 3 6.8kΩ V+ 4 0.33µF IN+ Reg GND 8 GND V+ 7 V+ OUT 6 IN- 5 47kΩ 15kΩ 2.2µF Output 9kΩ 4.7µF 680Ω [VNO] A-Weighted Rg=600Ω –3– NJM2781 Test Circuit 3 (Operating Current Icc1,Icc2) 1µF 8 V+ 7 3 OUT 6 4 IN- 5 REG 10µF 2 100Ω 10µF 6.8kΩ Input V+ NOISE GND 1 Reg STBY IN+ 0.33µF GND V+ 47kΩ 2.2µF 15kΩ Output 9kΩ 4.7µF 680Ω Icc1:STBY=L Icc2:STBY=H Test Circuit 4 (Mic Power Supply Voltage Vo) 1µF 8 GND V+ 7 V+ 3 OUT 6 4 IN- 5 REG 6.8kΩ 2 10µF 100Ω 10µF 6.8kΩ Input 0.33µF V+ –4– NOISE GND 1 STBY IN+ Reg 47kΩ 2.2µF 15kΩ 4.7µF 680Ω Output 9kΩ NJM2781 Test Circuit 5 (Power Supply Ripple Rejection PSRR) 1µF 1 NOISE REG 10µF 2 100Ω 10µF Input Reg STBY 3 6.8kΩ 4 V+ GND 8 V+ 7 OUT 6 IN- 5 IN+ 0.33µF GND V+ 47kΩ 2.2µF 15kΩ Output 9kΩ [PSRR] BPF:1kHz 4.7µF 680Ω Rg=600Ω Test Circuit 6 (Stand-By Control Voltage VIH, VIL) 1µF 1 NOISE REG 10µF 2 100Ω 10µF Input STBY 3 6.8kΩ 4 0.33µF IN+ Reg GND 8 GND V+ 7 V+ OUT 6 IN- 5 47kΩ 2.2µF 15kΩ Output 9kΩ 4.7µF 680Ω –5– NJM2781 ■ APPLICATION CIRCUIT 1µF 1 REG 10µF 2 100Ω 10µF Input STBY 3 6.8kΩ V+ –6– NOISE 4 0.33µF IN+ Reg GND 8 GND V+ 7 V+ OUT 6 IN- 5 47kΩ 2.2µF 15kΩ 4.7µF 680Ω 9kΩ Output NJM2781 ■ TERMINAL DESCRIPTION PIN NO. SYMBOL 1 NOISE FUNCTION TERMINAL VOLTAGE EQUIVALENT CIRCUIT Noise Bypass V+ V+ V+ V+ 3.6k 0.54V NOISE 500 27k 2 REG Regulator Output V+ V+ V+ 8k REG 3 STBY 2.42V Standby On/Off V+ V+ STBY 460 30k 0V 30k 4 IN+ Non-Inverted Input V+ REG 48k 1.35V IN+ 76k 60k –7– NJM2781 ■ TERMINAL DESCRIPTION PIN NO. SYMBOL 5 IN- FUNCTION TERMINAL VOLTAGE EQUIVALENT CIRCUIT Inverted Input V+ 1.35V IN- 6 OUT Output V+ V+ 300 OUT 16p –8– 1.35V NJM2781 ■ SPECIFICATIONS Operating Current vs. Ambient Temperature (Standby) Operating Current vs. Pow er Supply Voltage (Standby) RL=9kΩ,Ta=25°C 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0 -0.2 -0.4 0.2 0 -0.2 -0.4 -0.6 -0.6 -0.8 -0.8 -1 0 1 V+=2.8V,RL=9kΩ 1 Operating Current [µA] Operating Current [µA] 1 2 3 Pow er Supply Voltage [V] 4 -1 -40 5 Operating Current vs. Pow er Supply Voltage (Active) 10 60 Ambient Teperature [°C] Operating Current vs. Ambient Temperature (Active) V+=2.8V,RL=9kΩ 2.5 2.5 2 2 Operating Current [mA] Operating Current [mA] RL=9kΩ,Ta=25°C 1.5 1 0.5 1.5 1 0.5 0 0 -0.5 -40 -0.5 0 1 2 3 Pow er Supply Voltage [V] 4 5 Operating Current vs. Standby Voltage 10 60 Ambient Temperature [°C] 110 Output Voltage vs. Input Voltage (Standby) V+=2.8V,RL=9kΩ,Ta=25°C 2.5 f=1kHz,RL=9kΩ,Ta=25°C 0 2 -20 1.5 Output Voltage [dBV] Operating Current [mA] 110 1 0.5 0 -40 -60 -80 -100 -120 -0.5 0 0.5 1 1.5 2 Standby Voltage [V] 2.5 3 -140 -40 -30 -20 -10 Input Voltage [dBV] 0 –9– NJM2781 Mic Pow er Supply Voltage vs. Pow er Supply Voltage Mic Pow er Supply Voltage vs. Ambient Temperature RL=6.8kΩTa=25°C 3 V+=2.8V,RL=6.8kΩ 3 2.5 Mic Power Supply Voltage [V] Mic Power Supply Voltage [V] 2.5 2 1.5 1 0.5 0 2 1.5 1 0.5 0 -0.5 0 1 2 3 Pow er Supply Voltage [V] -0.5 -40 4 110 Voltage Gain vs. Ambient Temperature Voltage Gain vs. Frequency V+=2.8V,Vin=-40dBV,f=1kHz,RL=9kΩ V+=2.8V,Vin=-40dBV,RL=9kΩ,Ta=25°C 30 30 28 28 Voltage Gain [dB] Voltage Gain [dB] 10 60 Ambient Temperature [°C] 26 24 26 24 22 22 20 10 10E+0 100 100E+0 1k 1E+3 10k 10E+3 100k 100E+3 20 -40 Frequency [Hz] Votage Gain vs. Standby Voltage (Ta) V+=2.8V,RL=9kΩ,Rg=600Ω,A-w eighted -80 20 -85 0 -90 -20 Output Noise [dBV] Voltage Gain [dB] 110 Output Noise vs. Ambient Temperature V+=2.8V,Vin=-40dBV,f=1kHz,RL=9kΩ 40 10 60 Ambient Temperature [°C] Ta=-40°C Ta=85°C -40 Ta=25°C -60 -80 -95 -100 -105 -110 -100 -115 -120 0 – 10 – 0.5 1 1.5 2 Standby Voltage [V] 2.5 3 -120 -40 10 60 Ambient Temperature [°C] 110 NJM2781 Total Harmonic Distortion vs. Output Voltage (V+) Total Harmonic Distortion vs. Output Voltage (Ta) Vin=-40dBV,RL=9kΩ,Ta=25°C V+=2.7V V+=2.8V V+=4.5V 1 THD+N ％ [ ] THD+N ％ [ ] 1 0.1 Ta=-40°C Ta= 25°C Ta= 85°C 0.1 0.01 0.01 0.001 -35 -25 -15 Output Voltage [dBV] -5 5 0.001 -35 10 -15 -5 5 Pow er Supply Ripple Rejection vs. Frequency V+=2.8V,RL=9kΩ,Ta=25°C 100 f=100Hz : BW= 10-22kHz f=1kHz : BW=400-22kHz f=10kHz : BW=400-80kHz V+=2.8V,Vin=-40dBV,RL=9kΩ,Ta=25°C 80 1 PSRR [dB] f=10kHz 0.1 0.01 -25 Output Voltage [dBV] Total Harmonic Distortion vs. Output Voltage ( f ) THD+N ％ [ ] V+=2.8V,f=1kHz,RL=9kΩ 10 10 f=100Hz 60 40 20 f=1kHz 0.001 -35 -25 -15 Output Voltage [dBV] -5 5 0 10 10E+0 100 100E+0 1k 1E+3 Frequency [Hz] 10k 10E+3 100k 100E+3 [CAUTION] The specifications on this data book are only given for information, without any guarantee as regards either mistakes or omissions. The application circuits in this data book 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. – 11 –