LT1781 - Low Power 5V RS232 Dual Driver/Receiver with ±15kV ESD Protection
Features
- 10mA Max Supply Current
- ESD Protection to IEC 1000-4-2 Level 4 ±15kV Air Gap, ±8kV Contact
- Uses Small Capacitors: 0.1µF
- 120kBaud Operation for RL = 3k, CL = 2500pF
- 250kBaud Operation for RL = 3k, CL = 1000pF
- Outputs Withstand ±30V Without Damage
- CMOS Comparable Low Power: 40mW
- Operates from a Single 5V Supply
- Rugged Bipolar Design
- Outputs Assume a High Impedance State When Off
or Powered Down - Meets All RS232 Specifications
- Available With or Without Shutdown
- Absolutely No Latch-up
Typical Application
Description
The LT®1780/LT1781 are dual RS232 driver/receiver pairs with integral charge pump to generate RS232 voltage levels from a single 5V supply. Using only 0.1µF external capacitors, these circuits consume only 40mW of power, and can operate to 120kbaud even while driving heavy capacitive loads. New ESD structures on the chip allow the LT1780/LT1781 to survive ±15kV air gap and ±8kV contact ESD tests per IEC 1000-4-2, eliminating the need for costly TransZorbs® on the RS232 line pins. The LT1780/LT1781 are fully compliant with EIA RS232 standards. Driver outputs are protected from overload, and can be shorted to ground or up to ±30V without damage. During SHUTDOWN or power-off conditions, driver and receiver outputs are in a high impedance state, allowing line sharing. The LT1780/LT1781 are direct upgrades to the LT1180A/LT1181A, LT1280A/LT1281A and LT1381 for applications which require the utmost ESD protection. The LT1781 is available in 16-pin DIP,SO and SW packages. The LT1780 is supplied in 18-pin DIP and SW packages for applications which require SHUTDOWN.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 |
|---|---|---|---|---|---|
| LT1781CN#PBF | N-16 | N | C | 05-08-1510 (N16) | Yes |
| LT1781CS#PBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1781CS#TRPBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LT1781CSW#PBF | SW-16 | SW | C | 05-08-1620 (SW16) | Yes |
| LT1781CSW#TRPBF | SW-16 | SW | C | 05-08-1620 (SW16) | Yes |
| LT1781IN#PBF | N-16 | N | I | 05-08-1510 (N16) | Yes |
| LT1781IS#PBF | SO-16 | S | I | 05-08-1610 (S16) | Yes |
| LT1781IS#TRPBF | SO-16 | S | I | 05-08-1610 (S16) | Yes |
| LT1781ISW#PBF | SW-16 | SW | I | 05-08-1620 (SW16) | Yes |
| LT1781ISW#TRPBF | SW-16 | SW | I | 05-08-1620 (SW16) | 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 | |
|---|---|---|---|---|---|---|
| LT1781CN#PBF | N-16 | C | $3.35 | $2.75 | Yes | |
| LT1781CS#PBF | SO-16 | C | $3.60 | $2.95 | Yes | |
| LT1781CS#TRPBF | SO-16 | C | $3.01 | Yes | ||
| LT1781CSW#PBF | SW-16 | C | $3.65 | $3.00 | Yes | |
| LT1781CSW#TRPBF | SW-16 | C | $3.06 | Yes | ||
| LT1781IN#PBF | N-16 | I | $4.40 | $3.40 | Yes | |
| LT1781IS#PBF | SO-16 | I | $4.65 | $3.60 | Yes | |
| LT1781IS#TRPBF | SO-16 | I | $3.66 | Yes | ||
| LT1781ISW#PBF | SW-16 | I | $4.85 | $3.70 | Yes | |
| LT1781ISW#TRPBF | SW-16 | I | $3.76 | 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.Click here to view our complete list of demo boards
Applications
- Portable Computers
- Battery-Powered Systems
- Power Supply Generator
- Terminals
- Modems
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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.
