Document
MCP3551/3
Low-Power, Single-Channel 22-Bit Delta-Sigma ADCs
Features
• 22-bit ADC in Small 8-pin MSOP Package with Automatic Internal Offset and Gain Calibration • Low-Output Noise of 2.5 µVRMS with Effective Resolution of 21.9 bits (MCP3551) • 3 µV Typical Offset Error • 2 ppm Typical Full-Scale Error • 6 ppm Maximum INL Error • Total Unadjusted Error Less Than 10 ppm • No Digital Filter Settling Time, Single-Command Conversions through 3-wire SPI™ Interface • Ultra-Low Conversion Current (MCP3551): - 100 µA typical (VDD = 2.7V) - 120 µA typical (VDD = 5.0V) • Differential Input with VSS to VDD Common Mode Range • 2.7V to 5.5V Single-Supply Operation • Extended Temperature Range: - -40°C to +125°C
Description
The Microchip Technology Inc. MCP3551/3 devices are 2.7V to 5.5V low-power, 22-bit Delta-Sigma Analog-to-Digital Converters (ADCs). The devices offer output noise as low as 2.5 µVRMS, with a total unadjusted error of 10 ppm. The family exhibits 6 ppm Integral Non-Linearity (INL) error, 3 µV offset error and less than 2 ppm full-scale error. The MCP3551/3 devices provide high accuracy and low noise performance for applications where sensor measurements (such as pressure, temperature and humidity) are performed. With the internal oscillator and high oversampling rate, minimal external components are required for high-accuracy applications. This product line has fully differential analog inputs, making it compatible with a wide variety of sensor, industrial control or process control applications. The MCP3551/3 devices operate from -40°C to +125°C and are available in the space-saving 8-pin MSOP and SOIC packages.
Applications
• • • • • • Weigh Scales Direct Temperature Measurement 6-digit DVMs Instrumentation Data Acquisition Strain Gauge Measurement
Package Types:
MCP3551/3
SOIC, MSOP VREF 1 VIN+ 2 VIN– 3 VSS 4
VSS VDD
8 VDD 7 CS 6 SDO/RDY 5 SCK
Block Diagram
VREF
Device Selection Table
SINC 4 VIN+ VINSerial Interface
3rd-Order ΔΣ ADC Modulator w/ Internal Calibration
SCK SDO RDY CS
Part Number MCP3551 MCP3553
Sample Rate 13.75 sps 60 sps
Effective Resolution 21.9 bits 20.6 bits
50/60 Hz Rejection 50/60 Hz (simultaneous) N/A
Internal Oscillator
VDD POR
© 2005 Microchip Technology Inc.
DS21950B-page 1
MCP3551/3
1.0
1.1
ELECTRICAL CHARACTERISTICS
Maximum Ratings*
VDD...................................................................................7.0V All inputs and outputs w.r.t VSS ............. –0.3V to VDD + 0.3V Difference Input Voltage ....................................... |VDD - VSS| Output Short Circuit Current ................................. Continuous Current at Input Pins ....................................................±2 mA Current at Output and Supply Pins ............................±10 mA Storage Temperature.....................................-65°C to +150°C Ambient temp. with power applied ................-55°C to +125°C ESD protection on all pins (HBM, MM) ............ ≥ 6 kV, ≥ 400V Maximum Junctio.