MCP3918 Datasheet, PDF (1/88 Pages) Microchip Technology – 3V Single-Channel Analog Front End

MCP3918
3V Single-Channel Analog Front End
Features:
• One 24-bit Resolution Delta-Sigma A/D Converter
• 93.5 dB SINAD, -107 dBc Total Harmonic
Distortion (THD) (up to 35^th harmonic), 112 dB
Spurious-Free Dynamic Range (SFDR)
• Flexible Serial Interface that Includes Both SPI
and a Simple 2-Wire Interface Ideal for Polyphase
Shunt Energy Meters
• Advanced Security Features:
- 16-bit Cyclic Redundancy Check (CRC)
Checksum on All Communications for Secure
Data Transfers
- 16-bit CRC Checksum and Interrupt Alert for
Register-Map Configuration
- Register-Map Lock with 8-bit Secure Key
• 2.7V – 3.6V AV_DD, DV_DD
• Programmable Data Rate, up to 125 ksps:
- 4 MHz Maximum Sampling Frequency
- 16 MHz Maximum Master Clock
• Oversampling Ratio, up to 4096
• Ultra Low-Power Shutdown Mode with < 10 µA
• Low-Drift 1.2V Internal Voltage Reference:
9 ppm/°C
• Differential Voltage Reference Input Pins
• High-Gain Programmable Gain Amplifier (PGA)
(up to 32 V/V)
• Phase Delay Compensation with 1 µs Time
Resolution
• Separate Data Ready Pin for Easy
Synchronization
• Individual 24-bit Digital Offset and Gain Error
Correction
• High-Speed 20 MHz SPI Interface with Mode 0,0
and 1,1 Compatibility
• Continuous Read/Write Modes for Minimum
Communication with Dedicated 16-/32-bit Modes
• Available in 20-lead QFN and SSOP Packages
• Extended Temperature Range: -40°C to +125°C
(all specifications are valid down to -45°C)
Description:
The MCP3918 is a 3V single-channel Analog Front End
(AFE), containing one delta-sigma, Analog-to-Digital
Converter (ADC), one programmable gain amplifier
(PGA), phase delay compensation block, low-drift
internal voltage reference, digital offset and gain errors
calibration registers, and high-speed 20 MHz
SPI-compatible serial interface.
The MCP3918 ADC is fully configurable with features
such as: 16-/24-bit resolution, Oversampling Ratio
(OSR) from 32 to 4096, gain from 1x to 32x,
independent Shutdown and Reset, dithering and
auto-zeroing. Communication is largely simplified with
8-bit commands, including various continuous
read/write modes and 16-/24-/32-bit data formats that
can be accessed by the Direct Memory Access (DMA)
of an 8-/16-/32-bit MCU, and with the separate Data
Ready pin that can be directly connected to an Interrupt
Request (IRQ) input of an MCU.
The MCP3918 includes advanced security features to
secure the communications and the configuration
settings, such as a CRC-16 checksum on both serial
data outputs and on the register-map static
configuration. It also includes a register-map lock
through an 8-bit password to avoid the processing of
any unwanted write commands.
For polyphase shunt-based energy meters, the
MCP3918 2-Wire serial interface greatly reduces
system cost, requiring only a single bidirectional
isolator per phase.
The MCP3918 is capable of interfacing a variety of
voltage and current sensors, including shunts, current
transformers, Rogowski coils and Hall effect sensors.
Applications:
• Single-Phase and Polyphase Energy Meters
• Energy Metering and Power Measurement
• Automotive
• Portable Instrumentation
• Medical and Power Monitoring
• Audio/Voice Recognition
• Isolator Sensor Application
 2014 Microchip Technology Inc.
DS20005287A-page 1