NJU72343, NJU72750A, NJU72751A | New product news for Electronic Devices | Nisshinbo Micro Device(NJR) | News

New Product

April 12, 2016

New JRC introduces 3 Audio ICs Electronic Volume NJU72343, Analog Switch NJU72750A and NJU72751A that realize high-quality, low-distortion and low-noise audio equipment

New JRC provides 3 audio ICs "Electronic Volume NJU72343, Analog Switch NJU72750A and NJU72751A" for improving the sound quality of audio equipment. These 3 audio ICs can make audio equipment to achieve high quality sound, low distortion and low noise.

General Description

In order to realize high quality sound, low distortion and low noise, now mainly use audio selector consisting of electronic volume and analog switch in audio equipment. These developed Electronic Volume NJU72343, Analog Switch NJU72750A and NJU72751A adopt the New JRC’s circuit design technology and semiconductor process technology of high quality sound, low distortion and low noise that have been cultivated so far.

To improve the sound quality, it is necessary to change the sound processing quality of audio selector parts. The combination of these products can make audio equipment to achieve high quality sound, low distortion and low noise. Not only that, these products can be controlled by the same serial bus, so you can flexibly configure the number of input and output signals and the number of channels according to the needs of different systems.

Features

Realize high quality sound, low distortion and low noise

NJU72343 is an electronic volume for high quality sound that considers low noise and THD (Total Harmonic Distortion) characteristic in high frequency. NJU72750A and NJU72751A are analog switches with low ON resistance that can reduce noise voltage and THD of audio equipment.
Conventional analog switch has a great ON resistance in audio selector. In order to prevent THD from increasing, an operational amplifier has been used after analog switch. Because NJU72750A and NJU72751A have low ON resistance, even if omit the operational amplifier, it is possible to achieve low distortion. Without the noise of the operational amplifier, audio equipment can more easily achieve high quality sound and low noise.

**THD+N vs Output Voltage**
f=1kHz, BW: 400Hz to 30kHz　／　f=20kHz, BW: 400Hz to 80kHz

Flexible system extensibility

We provide the product lineup considering extensibility that you can flexibly configure the number of input and output signals and the number of channels depending on the system configuration. Using address selection pin, you can control maximum 2 NJU72343 ICs, 4 NJU72750A ICs or 4 NJU72751A ICs by the same serial bus.

Original 2-wired serial bus interface

These products adopt 2-wired serial bus interface control mode that is similar to I²C serial bus interface. This signal control mode removed the acknowledge signal (ACK). The acknowledge signal generates a few mA current flow to the ground, which has adverse impact on audio signal path in control mode. This original 2-wired serial bus interface can suppress the impact.
Moreover, conventional I²C serial bus interface used open-drain port. But this 2-wired serial bus interface is not restricted to the open-drain port.

Characteristics

	NJU72343	NJU72750A	NJU72751A
Functions	8ch. Electronic volume	7-input 3-output 2-circuit Analog switch	4-input 4-output 2-circuit Analog switch
Operating Supply Voltage	Dual： ±4.5 to ±7.5V Single: +9.0 to +15.0V	Dual： ±4.5 to ±7.5V Single: +9.0 to +15.0V	Dual： ±4.5 to ±7.5V Single: +9.0 to +15.0V
Serial Control	2-wired	2-wired	2-wired
Chip Address	2	2	4
THD (Vin=1Vrms, f=1kHz)	0.0004% typ.	0.0004% typ	0.0004% typ.
Output Noise Voltage	-117dBV typ.	-	-
Switch ON Resistance	-	15Ω typ.	15Ω typ.
Others	Independent Volume Control Volume: +31.5 to -95dB 2-input Selector(4ch.)	Independent Switch Control Low Impedance Switch	Independent Switch Control Low Impedance Switch
Package	SSOP32	SSOP32	SSOP32