MCP3426/7/8 16-Bit, Multi-Channel Analog-to-Digital Converter with 2 I C Interface and On-Board Reference Features Description 16-bit ADC with Differential Inputs: The MCP3426, MCP3427 and MCP3428 devices (MCP3426/7/8) are the low noise and high accuracy - 2 channels: MCP3426 and MCP3427 16Bit Delta-Sigma Analog-to-Digital ( A/D) Con- - 4 channels: MCP3428 verter family members of the MCP342X series from Differential Input Full Scale Range: -V to REF Microchip Technology Inc. These devices can convert +V REF analog inputs to digital codes with up to 16 bits of reso- Self Calibration of Internal Offset and Gain per lution. Each Conversion The MCP3426 and MCP3427 devices have two On-Board Voltage Reference (V ): REF differential input channels and the MCP3428 has four - Accuracy: 2.048V 0.05% differential input channels. All electrical properties of - Drift: 15 ppm/C these three devices are the same except the 2 differences in the number of input channels and I C On-Board Programmable Gain Amplifier (PGA): address bit selection options. - Gains of 1,2, 4 or 8 These devices can output analog-to-digital conversion INL: 10 ppm of Full Scale Range results at rates of 15 (16-bit mode), 60 (14-bit mode), or Programmable Data Rate Options: 240 (12-bit mode) samples per second depending on - 15 SPS (16 bits) the user controllable configuration bit settings using the - 60 SPS (14 bits) 2 two-wire I C serial interface. During each conversion, - 240 SPS (12 bits) the device calibrates offset and gain errors One-Shot or Continuous Conversion Options automatically. This provides accurate conversion results from conversion to conversion over variations in Low Current Consumption (V = 3V): DD temperature and power supply fluctuation. - Continuous Conversion: 135 A typical The device has an on-board 2.048V reference voltage, - One-Shot Conversion with 1 SPS: which enables an input range of 2.048V differentially - 9 A typical for 16 bit mode (full scale range = 4.096/PGA). - 2.25 A typical for 14 bit mode - 0.56 A typical for 12 bit mode The user can select the gain of the on-board On-Board Oscillator programmable gain amplifier (PGA) using the 2 configuration register bits (gain of x1, x2, x4, or x8). I C Interface: This allows the MCP3426/7/8 devices to convert a very - Standard, Fast and High Speed Modes weak input signal with high resolution. - User configurable two external address The MCP3426/7/8 devices have two conversion selection pins for MCP3427 and MCP3428 modes: (a) One-Shot Conversion mode and Single Supply Operation: 2.7V to 5.5V (b)Continuous Conversion mode. In the One-Shot Extended Temperature Range: -40C to +125C conversion mode, the device performs a single conversion and enters a low current standby Typical Applications (shutdown) mode automatically until it receives another conversion command. This reduces current Portable Instrumentation and Consumer Goods consumption greatly during idle periods. In continuous Temperature Sensing with RTD, Thermistor, and conversion mode, the conversion takes place Thermocouple continuously at the configured conversion speed. The Bridge Sensing for Pressure, Strain, and Force device updates its output buffer with the most recent Weigh Scales and Battery Fuel Gauges conversion data. Factory Automation Equipment The devices operate from a single 2.7V to 5.5V power 2 supply and have a two-wire I C compatible serial interface for a standard (100 kHz), fast (400 kHz), or high-speed (3.4 MHz) mode. 2009 Microchip Technology Inc. DS22226A-page 1MCP3428 MCP3427 MCP3426 MCP3426/7/8 2 The I C address bits for the MCP3427 and MCP3428 The MCP3426 is available in 8-pin SOIC, DFN, and 2 are selected by using two external I C address MSOP packages. The MCP3427 is available in 10-pin selection pins (Adr0 and Adr1). The user can configure DFN, and MSOP packages. The MCP3428 is available the device to one of eight available addresses by in 14-pin SOIC and TSSOP packages. connecting these two address selection pins to V , DD 2 V or float. The I C address bits of the MCP3426 are SS programmed at the factory during production. Package Types MSOP, SOIC MSOP SOIC, TSSOP CH1+ CH1+ 1 14 10 Adr1 CH4- 1 CH1+ 8 1 CH2- CH1- 2 9 CH1- 2 13 Adr0 CH4+ CH1- 7 2 CH2+ V 3 8 SCL 12 SS 3 V CH2+ CH3- 3 6 V DD SS CH2+ 4 7 SDA 4 5 SCL 4 11 SDA CH2- CH3+ V CH2- 5 6 DD 5 V 10 Adr1 SS 6 9 V Adr0 DD 7 8 SDA SCL MCP3426 MCP3427 2x3 DFN * 3x3 DFN * CH1+ CH2- CH1+ Adr1 1 8 1 10 CH1- CH2+ CH1- Adr0 2 7 2 9 EP EP 9 V V V SCL 3 6 3 8 DD SS SS 11 SDA 4 5 SCL CH2+ 4 7 SDA CH2- 5 6 V DD * Includes Exposed Thermal Pad (EP) see Table 3-1. MCP3426 Functional Block Diagram V V DD SS Voltage Reference MCP3426 (2.048V) V REF CH1+ SCL 2 I C ADC CH1- PGA Converter SDA Interface CH2+ Gain = 1, 2, 4, or 8 CH2- Clock Oscillator DS22226A-page 2 2009 Microchip Technology Inc. MUX