MCP3421 18-Bit Analog-to-Digital Converter 2 with I C Interface and On-Board Reference Features Description 18-bit ADC in a SOT-23-6 package The MCP3421 is a single channel low-noise, high accuracy A/D converter with differential inputs and Differential Input Operation up to 18 bits of resolution in a small SOT-23-6 package. Self Calibration of Internal Offset and Gain Per The on-board precision 2.048V reference voltage Each Conversion enables an input range of 2.048V differentially On-Board Voltage Reference: 2 ( voltage = 4.096V). The device uses a two-wire I C - Accuracy: 2.048V 0.05% compatible serial interface and operates from a single - Drift: 15 ppm/C 2.7V to 5.5V power supply. On-Board Programmable Gain Amplifier (PGA): The MCP3421 device performs conversion at rates of - Gains of 1,2, 4 or 8 3.75, 15, 60, or 240 samples per second (SPS) On-Board Oscillator depending on the user controllable configuration bit 2 C serial interface. This settings using the two-wire I INL: 10 ppm of FSR (FSR = 4.096V/PGA) device has an on-board programmable gain amplifier Programmable Data Rate Options: (PGA). The user can select the PGA gain of x1, x2, x4, - 3.75 SPS (18 bits) or x8 before the analog-to-digital conversion takes - 15 SPS (16 bits) place. This allows the MCP3421 device to convert a - 60 SPS (14 bits) smaller input signal with high resolution. The device has two conversion modes: (a) Continuous mode and - 240 SPS (12 bits) (b) One-Shot mode. In One-Shot mode, the device One-Shot or Continuous Conversion Options enters a low current standby mode automatically after Low Current Consumption: one conversion. This reduces current consumption - 145 A typical greatly during idle periods. (V = 3V, Continuous Conversion) DD The MCP3421 device can be used for various high - 39 A typical accuracy analog-to-digital data conversion applications (V = 3V, One-Shot Conversion with 1 SPS) DD where design simplicity, low power, and small footprint 2 Supports I C Serial Interface: are major considerations. - Standard, Fast and High Speed Modes Single Supply Operation: 2.7V to 5.5V Block Diagram Extended Temperature Range: -40C to +125C V V SS DD Typical Applications Voltage Reference Portable Instrumentation (2.048V) Weigh Scales and Fuel Gauges Gain = 1, 2, 4, or 8 V Temperature Sensing with RTD, Thermistor, and REF Thermocouple V + IN Bridge Sensing for Pressure, Strain, and Force. ADC Clock PGA Oscillator Converter Package Types V - SOT-23-6 MCP3421 IN 2 V + 6 I C Interface IN 1 V - IN V 5 V 2 SS DD 3 4 SDA SCL SCL SDA 2009 Microchip Technology Inc. DS22003E-page 1MCP3421 NOTES: DS22003E-page 2 2009 Microchip Technology Inc.