LTC6820 - isoSPI Isolated Communications Interface
Features
- 1Mbps Isolated SPI Data Communications
- Simple Galvanic Isolation Using Standard Transformers
- Bidirectional Interface Over a Single Twisted Pair
- Supports Cable Lengths Up to 100 Meters
- Very Low EMI Susceptibility and Emissions
- Configurable for High Noise Immunity or Low Power
- Engineered for ISO26262 Compliant Systems
- Requires No Software Changes in Most SPI Systems
- Ultralow, 2μA Idle Current
- Automatic Wake-Up Detection
- Operating Temperature Range: –40°C to 125°C
- 2.7V to 5.5V Power Supply
- Interfaces to All Logic from 1.7V to 5.5V
- Available in 16-Lead QFN and MSOP Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC®6820 provides bidirectional SPI communications between two isolated devices through a single twisted pair connection. Each LTC6820 encodes logic states into signals that are transmitted across an isolation barrier to another LTC6820. The receiving LTC6820 decodes the transmission and drives the slave bus to the appropriate logic states. The isolation barrier can be bridged by a simple pulse transformer to achieve hundreds of volts of isolation.
The LTC6820 drives differential signals using matched source and sink currents, eliminating the requirement for a transformer center tap and reducing EMI. Precision window comparators in the receiver detect the differential signals. The drive currents and the comparator thresholds are set by a simple external resistor divider, allowing the system to be optimized for required cable lengths and desired signal-to-noise performance.
Packaging
CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.
For complete and up to date package information and drawings, please refer to our packaging page
| Part Number | Package | Code | Temp | Package Drawing |
RoHS |
|---|---|---|---|---|---|
| LTC6820HMS#PBF | MS-16 | MS | H | 05-08-1669 | Yes |
| LTC6820HMS#TRPBF | MS-16 | MS | H | 05-08-1669 | Yes |
| LTC6820HUD#PBF | 3x3 QFN-16 | UD | H | 05-08-1700 | Yes |
| LTC6820HUD#TRPBF | 3x3 QFN-16 | UD | H | 05-08-1700 | Yes |
| LTC6820IMS#PBF | MS-16 | MS | I | 05-08-1669 | Yes |
| LTC6820IMS#TRPBF | MS-16 | MS | I | 05-08-1669 | Yes |
| LTC6820IUD#PBF | 3x3 QFN-16 | UD | I | 05-08-1700 | Yes |
| LTC6820IUD#TRPBF | 3x3 QFN-16 | UD | I | 05-08-1700 | Yes |
Order Info
- Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
- Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
- Please refer to our general ordering information or the product datasheet for more details
Package Variations and Pricing
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC6820HMS#PBF | MS-16 | H | $3.58 | $2.57 | Yes | |
| LTC6820HMS#TRPBF | MS-16 | H | $2.63 | Yes | ||
| LTC6820HUD#PBF | 3x3 QFN-16 | H | $3.58 | $2.57 | Yes | |
| LTC6820HUD#TRPBF | 3x3 QFN-16 | H | $2.63 | Yes | ||
| LTC6820IMS#PBF | MS-16 | I | $3.20 | $2.29 | Yes | |
| LTC6820IMS#TRPBF | MS-16 | I | $2.35 | Yes | ||
| LTC6820IUD#PBF | 3x3 QFN-16 | I | $3.20 | $2.29 | Yes | |
| LTC6820IUD#TRPBF | 3x3 QFN-16 | I | $2.35 | Yes | ||
| Buy Now • Request Samples | ||||||
Demo Boards
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1907A | LTC6820 isoSPI 2-Wire Serial Analyzer | $150.00 | |
| DC1941D | LTC6820 isoSPI Demoboard (DC590B required) | $75.00 | |
| DC2100B-C | 12 Cell 4A Controller Board. Bi-Directional Active Cell Balancer with LTC3300-1, LTC6804-2 & LTC6820 | $475.00 | |
| Buy Now | |||
Companion Boards
| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1894B | LTC6804-1 Demo Board | Precision Battery Monitoring System (req DC2026) | $150.00 | |
| DC1942C | LTC6804-2 Demo Board | Addressable isoSPI Battery-Stack Monitor (DC2026) | $150.00 | |
| DC2026C | Linduino One Isolated USB Demo Board: An Arduino- and QuikEval-Compatible Code Development Platform | $75.00 | |
| DC590B | Isolated USB Serial Controller for Linear Technology QuikEval-Compatible Demo Boards | $50.00 | |
| Buy Now | |||
Designed for Automotive and Transportation Applications
AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC6820HMS#PBF | MS-16 | H | $3.58 | $2.57 | Yes | |
| LTC6820HMS#TRPBF | MS-16 | H | $2.63 | Yes | ||
| LTC6820HUD#PBF | 3x3 QFN-16 | H | $3.58 | $2.57 | Yes | |
| LTC6820HUD#TRPBF | 3x3 QFN-16 | H | $2.63 | Yes | ||
| LTC6820IMS#PBF | MS-16 | I | $3.20 | $2.29 | Yes | |
| LTC6820IMS#TRPBF | MS-16 | I | $2.35 | Yes | ||
| LTC6820IUD#PBF | 3x3 QFN-16 | I | $3.20 | $2.29 | Yes | |
| LTC6820IUD#TRPBF | 3x3 QFN-16 | I | $2.35 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Industrial Networking
- Battery Monitoring Systems
- Remote Sensors
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Design Tools
Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:
- LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
- LTpowerCAD - A complete power supply selection, synthesis and design tool
- LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
- PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
- Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
- LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
- And More!
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
