LTC6820 isoSPI Isolated Communications Interface FEATURES DESCRIPTION n AEC-Q100 Qualified for Automotive Applications The LTC 6820 provides bidirectional SPI communications n 1Mbps Isolated SPI Data Communications between two isolated devices through a single twisted- n Simple Galvanic Isolation Using Standard pair connection. Each LTC6820 encodes logic states into Transformers signals that are transmitted across an isolation barrier to n Bidirectional Interface Over a Single Twisted Pair another LTC6820. The receiving LTC6820 decodes the n Supports Cable Lengths Up to 100 Meters transmission and drives the slave bus to the appropri- n Very Low EMI Susceptibility and Emissions ate logic states. The isolation barrier can be bridged by n Configurable for High Noise Immunity or Low Power a simple pulse transformer to achieve hundreds of volts n Engineered for ISO26262 Compliant Systems of isolation. n Requires No Software Changes in Most SPI Systems The LTC6820 drives differential signals using matched n Ultralow, 2A Idle Current source and sink currents, eliminating the requirement n Automatic Wake-Up Detection for a transformer center tap and reducing EMI. Precision n Operating Temperature Range: 40C to 125C window comparators in the receiver detect the differential n 2.7V to 5.5V Power Supply signals. The drive currents and the comparator thresholds n Interfaces to All Logic from 1.7V to 5.5V are set by a simple external resistor divider, allowing the n Available in 16-Lead QFN and MSOP Packages system to be optimized for required cable lengths and desired signal-to-noise performance. APPLICATIONS All registered trademarks and trademarks are the property of their respective owners. Protected by U.S. patents, including 8908779. n Industrial Networking n Battery Monitoring Systems n Remote Sensors TYPICAL APPLICATION Microcontroller to SPI Slave Isolated Interface Data Rate vs Cable Length 1.2 MASTER CAT-5 ASSUMED C LTC6820 1.0 MSTR IP MOSI SDO MISO 120 0.8 SDI SCK SCK IM CS CS 0.6 0.4 100 METERS TWISTED PAIR REMOTE 0.2 SLAVE IC LTC6820 MSTR 0 IP 1 10 100 SDI MOSI 120 CABLE LENGTH (METERS) SDO MISO 6820 TA01b SCK IM SCK 6820 TA01a CS CS Rev C 1 Document Feedback For more information www.analog.com DATA RATE (Mbps)LTC6820 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2, 3) Input Supply Voltages (V and V ) to GND ...........6V Operating Temperature Range DD DDS Pin Voltages LTC6820I .............................................40C to 85C SCK, CS, EN ...............0.3V to V + 0.3V (6V Max) LTC6820H .......................................... 40C to 125C DDS IBIAS, SLOW, IP, IM .....0.3V to V + 0.3V (6V Max) Specified Temperature Range DD All Other Pin Voltages .............................. 0.3V to 6V LTC6820I .............................................40C to 85C Maximum Source/Sink Current LTC6820H .......................................... 40C to 125C IP, IM .................................................................30mA Storage Temperature Range .................. 65C to 150C MOSI, MISO, SCK, CS ........................................20mA Lead Temperature (Soldering, 10 sec) MSOP ...............................................................300C PIN CONFIGURATION TOP VIEW TOP VIEW 16 15 14 13 EN 1 16 IBIAS 2 ICMP MOSI 1 12 SLOW MOSI 15 MISO 3 14 GND MISO 2 11 MSTR 4 SLOW SCK 13 17 SCK 3 10 IP CS 5 12 MSTR 6 IP V 11 DDS CS 4 9 IM POL 7 10 IM 5 6 7 8 8 V PHA 9 DD MS PACKAGE 16-LEAD PLASTIC MSOP UD PACKAGE 16-LEAD (3mm 3mm) PLASTIC QFN T = 150C, JA = 120C/W JMAX T = 150C, = 58.7C/W JMAX JA EXPOSED PAD (PIN 17) PCB CONNECTION TO GND IS OPTIONAL ORDER INFORMATION PART MSL SPECIFIED TUBE (121PC) TAPE AND REEL (2500PC) MARKING* PACKAGE DESCRIPTION RATING TEMPERATURE RANGE LTC6820IUD PBF LTC6820IUD TRPBF LGFM 16-Lead (3mm 3mm) Plastic QFN 1 40C to 85C LTC6820HUD PBF LTC6820HUD TRPBF LGFM 16-Lead (3mm 3mm) Plastic QFN 1 40C to 125C AUTOMOTIVE PRODUCTS** PART MSL SPECIFIED TUBE (37PC) TAPE AND REEL (2500PC) MARKING* PACKAGE DESCRIPTION RATING TEMPERATURE RANGE LTC6820IMS PBF LTC6820IMS TRPBF 6820 16-Lead Plastic MSOP 1 40C to 85C LTC6820IMS 3ZZPBF LTC6820IMS 3ZZTRPBF 6820 16-Lead Plastic MSOP 1 40C to 85C LTC6820HMS PBF LTC6820HMS TRPBF 6820 16-Lead Plastic MSOP 1 40C to 125C LTC6820HMS 3ZZPBF LTC6820HMS 3ZZTRPBF 6820 16-Lead Plastic MSOP 1 40C to 125C Contact the factory for parts specified with wider operating temperature ranges.*The temperature grade is identified by a label on the shipping container. Tape and reel specifications. Some packages are available in 500 unit reels through designated sales channels with TRMPBF suffix. **Versions of this part are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. These models are designated with a 3ZZ suffix. Only the automotive grade products shown are available for use in automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for thesemodels. Rev C 2 For more information www.analog.com V EN DDS POL IBIAS PHA ICMP V GND DD