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Featured Products
Analog Front End (AFE) Series

We Support Your Product Development by Easy Board Design and Advanced Sensing.

Our AFE products feature low power consumption and high-precision signal processing and correspond to a wide variety of sensor applications. Our proprietary technology provides high noise immunity and excellent linearity, enabling faithful reproduction of sensor signals. In addition, the small package enables space-saving mounting, making it ideal for portable devices and IoT equipment.

NA2202 / NA2203 / NA2204
5V Analog Front Ends with High-precision Delta Sigma A-D Converter

Product Lineup
Overview

The NA2202/2203/2204 are high-precision AFEs with up to 128 times internal programmable gain amplifiers (PGAs) and multiplexers built-in. They allow flexible connection of multiple sensors and reduce man-hours required for constant setting. 5 V operating voltage is supported, making it an ideal choice for systems using microcontrollers.
Furthermore, the compact package size of 4.0 x 4.0 x 0.75 mm contributes to product miniaturization. They are ideal for applications requiring high accuracy and space saving.

Product Lineup
Product Operating Temperature Range Supply Voltage ADC Resolution Digital Calibration PGA Package
NA2202 -40°C to +125° Analog:
+2.7 to +5.5V(Unipolar)or
±2.5V(Bipolar)
Digital:
+2.7 to +5.5V
16 Vos, Gain 128V/V QFN4040-24-NB
4.0x4.0x0.75(mm) (Pitch: 0.5mm)
pin-compatible
NA2203 20
NA2204 24
Features

The internal 4-channel multiplexers enable detecting various multiple sensor signals.

Circuit example with temperature sensors connected to 3 channels

temperature sensors

Applying a small package QFN4040-24-NB (4mm square) contributes to achieving smaller size of the board set and mounting area.

  • QFN4040-24-NB
    • QFN4040-24-NB 4.0x4.0x0.75(mm)(Pitch: 0.5mm)
    • Since the NA2202 / NA2203 / NA2204 series are pin-compatible with each other, you can try each AFE with different ADC resolution for a same board to find the best one.

The disconnection detection function for such as sensors reduces the risk of false detection.

  • Error detection
    • When there is no disconnection
    • IBURN does not flow to 100kΩ
    • Thermoelectromotive force of type K thermocouple:

      VIN1P - VIN1N = -(a few mV) to +(a few mV)

    • ADC output is within normal range
  • Error detection
    • When there is a disconnection
    • IBURN flows to 100kΩ
    • VIN1P=AVDD-10µA*100kΩ=4V
      VIN1N=AVSS+10µA*100kΩ=1V
      VIN1P-VIN1N=3V
    • ADC output sticks to full scale so disconnection can be detected

NJU9101
Low Power Analog Front End

Product Lineup
Overview

The NJU9101 integrates low power operational amplifiers, an A/D converter, and a signal processing circuit into one chip, enabling smaller applications and low power consumption. The internal operational amplifiers achieve low power consumption, high precision and low noise at the same time by our circuit and process technology. Also, it contains a newly designed low-current A/D converter.
Functions include gain, offset and temperature drift calibration. They are easily adjustable from an MCU, which makes the NJU9101 helpful to shorten development period of gas monitors and create product series.

Product Lineup
Product Operating Temperature Range Supply Voltage ADC Resolution Operating Current Digital Calibration Package
NJU9101 -40℃ to +85℃ +2.4V to +3.6V 16-Bit (NFB), 32sps to 2k sps 4μA (OPA,OPB), 150μA (ADC) Vos, Gain EQFN-24-LE (4mmx4mm)
Features

High Precision, Low Noise and Low Current Consumption (about 5.0 µA), prolonging operating time of battery-powered systems

The NJU9101 not only has low power operational amplifiers and an A/D converter, but it can perform intermittent ON/OFF operation of each function block.
The standby current is as low as around 0.5 µA, which makes the NJU9101 suitable for battery powered systems.

High RF Noise Immunity against External Noise from such as Transceivers

The NJU9101 contains operational amplifiers with high RF noise immunity achieved by our analog circuit technology.
They prevent the AFE from malfunctioning caused by electric waves emitted from transceivers.

Containing Functions Effective for Gas Detection

The 3-bit chip address allows for detecting maximum 7 types of gas with a single detector.
It can check sensor connection status thanks to the sensor diagnostic function.
Connecting an external EEPROM enables automatical setup of the AFE according to the memory at its startup.

Combining the following circuit blocks makes the NJU9101 usable for various low consumption power signal applications.

1. Temperature Sensor Measurement

Write below code to measure Temperature.

  • Temperature Sensor
  • NJU9101 Circuit Block Name

    CIRCUIT BLOCK NAME SYMBOL
    2 Low Current Operational Amplifiers "OPA", "OPB"
    Bias Level Setting Register "BIASRES"
    100Ω Analog Switch "ANASW"
    Variable Gain Pre-Amplifier "PREAMP"
    Temperature Sensor "TempSensor"
    Internal Reference "INTVREF (2.048V)"
    16-Bit sigma delta ADC "16-Bit ADC"
    Digital Control & Calibration "Control & Calibration"
    I2C Bus Compatible Control "I2C"
No. CONTENTS REGISTER ADDRESS REGISTER NAME BIT NAME BIT VALUE
1 Select Temperature Input Mode 0x00 CTRL MEAS_SEL [2:1] 00
2 Select ADC Conversion Mode (Exp. Single Conversion) MEAS_SC [0] 0
3 Start AD Conversion MEAS [3] 1
4 Check completion of the AD conversion ('MEAS' bit = '0') -
5 Acquire AD conversion data (TMPDATA) 0x06
0x07
TMPDATA0
TMPDATA1
TMPDATA [9:0] -

2. System Example 1 (Potentiostat Measurement)

Write below code to constitute "potentiostat" and "trans-impedance amplifier."

  • Potentiostat Measurement
  •  
No. CONTENTS REGISTER ADDRESS REGISTER NAME BIT NAME BIT VALUE
1 Connect the switch 'BIASRES' and 'OPA' 0x0F BLKCONN0 BIASSWA [5] 1
2 Connect the switch 'BIASRES' and 'OPB' BIASSWB [4] 1
3 Select output of BIASRES 0x11 BLKCONN2 BIASSWN [3] 1
4 Bias level for 'trans-impedance amplifier' (GND to 1.7V) 0x10 BLKCONN1 OPA_BIAS [7:5] any
5 Bias level for 'potentiostat' (GND to 1.75V) OPB_BIAS [4:0] any
6 Powered on BIASRES, OPA, OPB, OSC 0x12 BLKCTRL BLKCTRL [7:0] 0xF0
7 Enable PREAMP 0x11 BLKCONN2 PAMPSEL [2] 1
8 Select Amp Input Mode 0x00 CTRL MEAS_SEL [2:1] 01
9 Set Measurement Mode for ADC (ex. Single conversion) MEAS_SC [0] 0
10 Start measurement MEAS [3] 1
11 Check completion of the AD conversion ('MEAS' bit = '0') -
12 Acquire AD conversion data (AMPDATA) 0x02
0x03
AMPDATA0
AMPDATA1
AMPDATA [15:0] -

3. System Example 2 (Differential Input)

Write below code to constitute "Differential Amplifier Input" by using OPA/OPB.

  • Differential Input
  •  
No. CONTENTS REGISTER ADDRESS REGISTER NAME BIT NAME BIT VALUE
1 Open OPA input switch 0x0F BLKCONN0 BIASSWA [5] 0
2 Open OPB input switch BIASSWB [4] 0
3 Select OPA sensor signal input 0x11 BLKCONN2 INPSWA [5] 1
4 Select OPB sensor signal input INPSWB [4] 1
5 Select OPB output BIASSWN [3] 0
6 Powered on OPA, OPB, OSC 0x12 BLKCTRL BLKCTRL [7:0] 0x70
7 Enable PREAMP 0x11 BLKCONN2 PAMPSEL [2] 1
8 Select Amp Input Mode 0x00 CTRL MEAS_SEL [2:1] 01
9 Set Measurement Mode for ADC (ex. Single conversion) MEAS_SC [0] 0
10 Start measurement MEAS [3] 1
11 Check completion of the AD conversion ('MEAS' bit = '0') -
12 Acquire AD conversion data (AMPDATA) 0x02
0x03
AMPDATA0
AMPDATA1
AMPDATA [15:0] -

4. System Example 3 (Single Input (Non-Inverting))

Write below code to constitute "Single Amplifier Input" by using OPA/OPB.

  • Single Input (Non-Inverting)
  •  
No. CONTENTS REGISTER ADDRESS REGISTER NAME BIT NAME BIT VALUE
1 Open OPA input switch 0x0F BLKCONN0 BIASSWA [5] 0
2 Close OPB input switch BIASSWB [4] 1
3 Select OPA sensor signal input 0x11 BLKCONN2 INPSWA [6] 1
4 Connect OPB positive input to GND INPSWB [5] 0
5 Select BIASRES output BIASSWN [3] 1
6 Powered on BIASRES, OPA, OPB, OSC 0x12 BLKCTRL BLKCTRL [7:0] 0xF0
7 Enable PREAMP 0x11 BLKCONN2 PAMPSEL [2] 1
8 Select Amp Input Mode 0x00 CTRL MEAS_SEL [2:1] 01
9 Set Measurement Mode for ADC (ex. Single conversion) MEAS_SC [0] 0
10 Start measurement MEAS [3] 1
11 Check completion of the AD conversion ('MEAS' bit = '0') -
12 Acquire AD conversion data (AMPDATA) 0x02
0x03
AMPDATA0
AMPDATA1
AMPDATA [15:0] -

5. Auxiliary (external Input) Measurement

Write below code to constitute "Differential Amplifier Input" by using PREAMP.

  • (external Input) Measurement
  •  
No. CONTENTS REGISTER ADDRESS REGISTER NAME BIT NAME BIT VALUE
1 Select AUXIN input 0x11 BLKCONN2 BIASSWN [3] 1
2 Enable PREAMP PAMPSEL [2] 1
3 Select Auxiliary input mode 0x00 CTRL MEAS_SEL [2:1] 10
4 Set Measurement Mode for ADC (ex. Single conversion) MEAS_SC [0] 0
5 Start measurement MEAS [3] 1
6 Check completion of the AD conversion ('MEAS' bit = '0') -
7 Acquire AD conversion data (AUXDATA) 0x02
0x03
AMPDATA0
AMPDATA1
AMPDATA [15:0] -

NA2201 / NJU9102 / NJU9102A
Digital Earth Leakage Current Detector IC, or Ground Fault Current Detect IC

Product Lineup
Overview

The NA2201 / NJU9102 / NJU9102A are digital earth leakage current detector ICs for earth leakage current breakers. They convert analog signals obtained from a zero-phase-sequence current transformer into digital data via a built-in ADC, and process the current leakage data based on earth leakage current detector condition. As a result of data processing, they output a one-shot pulse from the SCRT terminal when an analog signal is judged to a leakage condition, and turns on an external thyristor.
Among these three AFEs, the NA2201 contains a overvoltage detection function and supports over voltage detection (neutral conductor open-phase protection).

Product Lineup
Product Operating Temperature Range Supply Voltage ADC Resolution DC Current Detection Function Time Delay Function Package
NA2201 -40°C to +12°C 4.0V to 5.5V 14 Available 2 Systems (leakage / overvoltage) SSOP-16-BD
NJU9102 Unavailable Unavailable DMP-8
NJU9102A
Features

NA2201 Digital Earth Leakage Current Detector IC, or Ground Fault Current Detect IC With Over Voltage Detection / DC Current Detection

The NA2201 is an excellent choice for industrial applications that require high reliability.
It has AC ground fault leakage current detection, open neutral detection and DC current detection functions. Also, for use in EV battery chargers, the NA2201 has DC current detection and 2-system time delay functions.
It has settings that the circuit designer can select for a particular application. It is ideal for applications that are noise sensitive because of its internal sinc3 filtering.

  • Over Voltage Detection / DC Current Detection
  •  
  • NA2201 Block Diagram (Overvoltage Detection)

    Overvoltage Detection
  • NA2201 Block Diagram (DC Current Detection)

    DC Current Detection

NJU9102 / NJU9102A Digital Earth Leakage Current Detector IC, or Ground Fault Current Detect IC

    • The internal digital filter (LPF) can cut line noise and common noise, contributing to reducing the risk of malfunction.
      No need to add an active filter, so these ICs can help you reduce number of parts, evaluation man-hours and cost.
    • You can select whether or not the IC has five times trip level immediate detection according to your applications.
    • Configuring the earth leakage detector condition pin (TMD) makes it possible to choose Type A or Type AC.
    Sinc3 Filter
  • NJU9102 Block Diagram

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