LTC6820 - isoSPI Isolated Communications Interface

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.

  • 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
Typical Application
LTC6820 Typical Application
LTC6820 Typical Application
  • Industrial Networking
  • Battery Monitoring Systems
  • Remote Sensors
LTC6820 Package Drawing
LTC6820 Package Drawing
Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LTC6820HUD#PBF3x3 QFN-16H$3.58$2.57
LTC6820HUD#TRPBF3x3 QFN-16H$2.63
LTC6820IUD#PBF3x3 QFN-16I$3.20$2.29
LTC6820IUD#TRPBF3x3 QFN-16I$2.35
Demo Boards
Part NumberDescriptionPrice
DC1907ALTC6820 isoSPI 2-Wire Serial Analyzer$150.00
DC1941DLTC6820 isoSPI Demoboard (DC590B required)$75.00
DC2100B-C12 Cell 4A Controller Board. Bi-Directional Active Cell Balancer with LTC3300-1, LTC6804-2 & LTC6820$475.00
Companion Boards
Part NumberDescriptionPrice
DC1894BLTC6804-1 Demo Board | Precision Battery Monitoring System (req DC2026)$150.00
DC1942CLTC6804-2 Demo Board | Addressable isoSPI Battery-Stack Monitor (DC2026)$150.00
DC2026CLinduino One Isolated USB Demo Board: An Arduino- and QuikEval-Compatible Code Development Platform$75.00
DC590BIsolated USB Serial Controller for Linear Technology QuikEval-Compatible Demo Boards$50.00
Reliability Data
LT Journal
CAD Symbol
Related Products
LTC6820 - isoSPI 隔离式通信接口
LTC6820 - isoSPI Isolated Communications Interface
isoSPI 数据链路助力实现高可靠性车载电池系统
用于高压、高容量电池系统的低成本 isoSPI 耦合电路
R525 - Reliability Data
Low Cost isoSPI Coupling Circuitry for High Voltage High Capacity Battery Systems
LTC6820 Footprints and Symbols