Features and Benefits
- Easy Drive Technology Enables Rail-to-Rail Inputs with Zero Differential Input Current
- Directly Digitizes High Impedance Sensors with Full Accuracy
- 600nVRMS Noise
- GND to VCC Input/Reference Common Mode Range
- Programmable 50Hz, 60Hz or Simultaneous 50Hz/60Hz Rejection Mode
- 2ppm INL, No Missing Codes
- 1ppm Offset and 15ppm Total Unadjusted Error
- Selectable 2× Speed Mode (15Hz Using Internal Oscillator)
- No Latency: Digital Filter Settles in a Single Cycle
- Single Supply 2.7V to 5.5V Operation
- Internal Oscillator
- Available in a Tiny (3mm × 3mm) 10-Lead DFN Package
The LTC2484 combines a 24-bit No Latency ΔΣ™ analog-to-digital converter with patented Easy Drive™ technology. The patented sampling scheme eliminates dynamic input current errors and the shortcomings of on-chip buffering through automatic cancellation of differential input current. This allows large external source impedances and input signals with rail-to-rail input range to be directly digitized while maintaining exceptional DC accuracy.
The LTC2484 includes an on-chip oscillator. The LTC2484 can be configured to reject line frequencies. 50Hz, 60Hz or simultaneous 50Hz/60Hz line frequency rejection can be selected as well as a 2× speed-up mode.
The LTC2484 allows a wide common mode input range (0V to VCC) independent of the reference voltage. The reference can be as low as 100mV or can be tied directly to VCC. The LTC2484 includes an on-chip trimmed oscillator, eliminating the need for external crystals or oscillators. Absolute accuracy and low drift are automatically maintained through continuous, transparent, offset and full-scale calibration.
- Direct Sensor Digitizer
- Weight Scales
- Direct Temperature Measurement
- Strain Gauge Transducers
- Industrial Process Control
- DVMs and Meters
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
The DC2126A is a high-accuracy wireless temperature sensor, powered from ambient light, built using ADI integrated circuits. A 24-bit delta-sigma ADC reads a thermistor biased from a precision voltage reference. A switching power supply harvests energy from the built-in solar panel, and automatically switches over to the internal battery when no ambient light is available.
At the core of the DC2126A is the LTP5901-IPM, SmartMesh IP wireless mote (node), which provides the ultra-low power wireless mesh connectivity with >99.999% data reliability and communicates the temperature to a central access point (manager). The LTP5901-IPM has on board an ARM Cortex-M3 processor, which can be loaded with user-developed application code using the SmartMesh IP On-Chip Software Development Kit (On-Chip SDK). In the DC2126A, custom application code controls the duty cycling of the voltage reference, samples readings from the ADC and sends the data packet through the SmartMesh IP network, as detailed in this LT Journal article.
|LTC Part Number||Function||Benefits|
|LTC2484||24-bit delta-sigma ADC, reads thermistor||Easy-Drive inputs allow direct hook-up of thermistor|
|LT6654||Low Noise Voltage Reference||Bias thermistor for low noise reading of temperature|
|LTP5901-IPM||SmartMesh IP Mote PCB Module||Automatically forms low power, reliable wireless mesh network.Built-in microprocessor manages ADC and power supplies|
|LTC3330||Energy Harvesting DC/DC Converter||Prioritizes between solar power and battery power|
The DC2126A can be easily added to the DC9000B SmartMesh IP Starter Kit, or any SmartMesh IP network. Temperature readings are sent through the mesh network to a demonstration PC software GUI that displays temperature, and whether the DC2126A is running on solar power or on battery.
DC2126A Demo Manual - step by step instructions to operate the DC2126A
DC2126A Circuit Description (from LT Journal, July 2014) - describes theory of operation of the DC2126A circuit
SmartMesh IP Starter Kits - other SmartMesh IP demo boards
SmartMesh IP On-Chip Software Development Kit - Enables users to develop application code to run on a SmartMesh IP Mote
|Software Name||Software Description||Weblink|
|"DC2126A.exe"||Demonstration GUI software that displays temperature and power source data sent wirelessly through the mesh. Runs on the user's Windows PC connected to a SmartMesh IP network manager.||Part of the SmartMesh IP SDK|
|FTDI Driver||USB-to-Serial drivers for communication with a SmartMesh IP manager (e.g. DC9001B SmartMesh IP Evaluation manager)||Download VCP from ftdichip.com|
Demonstration circuit DC939 features the LTC2484, a 24-bit high performance DS analog-to-digital converter (ADC). The LTC2484 features 2ppm linearity, 0.5mV offset, and 600nV RMS noise. The input is fully differential, with input common mode rejection of 140 dB. The LTC2484 is available in a 10 pin DFN package and has an easy to use SPI interface. DC939 is a member of ADI's QuickEval™ family of demonstration boards. It is designed to allow easy evaluation of the LTC2484 and may be connected directly to the target applications analog signals while using the DC590 USB Serial Controller board and supplied software to measure performance. The exposed ground planes allow proper grounding to prototype circuitry. After evaluating with ADI's software, the digital signals can be connected to the end application’s processor / controller for development of the serial interface.
Tools & Simulations
Linduino is Analog Devices’ Arduino compatible system for developing and distributing firmware libraries and example code for our integrated circuits.
Press Release (1)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.