LTC2938 - Configurable 4-Supply Monitors with Watchdog Timer
Features
- Simultaneously Monitors Four (LTC2938) or Six Supplies (LTC2939)
- Sixteen User-Selectable Combinations of 5V, 3.3V, 2.5V, 1.8V, 1.5V, 1.2V and/or ± Adjustable Voltage Thresholds
- Guaranteed Threshold Accuracy: ±1.5%
- Adjustable Reset and Watchdog Timeout
- Low Supply Current: 80μA Typical
- Power Supply Glitch Immunity
- Guaranteed RST for VCC > 1V
- High Temperature Operation to 125°C
- 12-Pin 4mm x 3mm DFN or 12-Lead MSOP (LTC2938) and 16-Lead MSOP Package (LTC2939)
Typical Application
Description
The LTC2938/LTC2939 are configurable supply monitors for systems with up to four or six supply voltages that need watchdog supervision. One of sixteen preset or adjustable voltage monitor combinations can be selected using an external resistive divider connected to the program input. The preset voltage thresholds are accurate to ±1.5% over temperature. The LTC2938 and LTC2939 also feature adjustable inputs with a 0.5V nominal threshold.The reset and watchdog timeout periods are adjustable using external capacitors. Tight voltage threshold accuracy and glitch immunity ensure reliable reset operation without false triggering. The RST output is guaranteed to be in the correct state for VCC down to 1V. Each status output has a weak internal pull-up and may be externally pulled up to a user-defined voltage.
The 80μA supply current makes the LTC2938 and LTC2939 ideal for power conscious systems. The LTC2939 monitors up to six supplies and the LTC2938 monitors up to four supplies.
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 |
|---|---|---|---|---|---|
| LTC2938CDE#PBF | 4x3 DFN-12 | DE/UE | C | 05-08-1695 | Yes |
| LTC2938CDE#TRPBF | 4x3 DFN-12 | DE/UE | C | 05-08-1695 | Yes |
| LTC2938CMS#PBF | MS-12 | MS | C | 05-08-1668 | Yes |
| LTC2938CMS#TRPBF | MS-12 | MS | C | 05-08-1668 | Yes |
| LTC2938HDE#PBF | 4x3 DFN-12 | DE/UE | H | 05-08-1695 | Yes |
| LTC2938HDE#TRPBF | 4x3 DFN-12 | DE/UE | H | 05-08-1695 | Yes |
| LTC2938HMS#PBF | MS-12 | MS | H | 05-08-1668 | Yes |
| LTC2938HMS#TRPBF | MS-12 | MS | H | 05-08-1668 | Yes |
| LTC2938IDE#PBF | 4x3 DFN-12 | DE/UE | I | 05-08-1695 | Yes |
| LTC2938IDE#TRPBF | 4x3 DFN-12 | DE/UE | I | 05-08-1695 | Yes |
| LTC2938IMS#PBF | MS-12 | MS | I | 05-08-1668 | Yes |
| LTC2938IMS#TRPBF | MS-12 | MS | I | 05-08-1668 | 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 | |
|---|---|---|---|---|---|---|
| LTC2938CDE#PBF | 4x3 DFN-12 | C | $3.07 | $2.15 | Yes | |
| LTC2938CDE#TRPBF | 4x3 DFN-12 | C | $2.21 | Yes | ||
| LTC2938CMS#PBF | MS-12 | C | $3.07 | $2.15 | Yes | |
| LTC2938CMS#TRPBF | MS-12 | C | $2.21 | Yes | ||
| LTC2938HDE#PBF | 4x3 DFN-12 | H | $3.89 | $2.72 | Yes | |
| LTC2938HDE#TRPBF | 4x3 DFN-12 | H | $2.78 | Yes | ||
| LTC2938HMS#PBF | MS-12 | H | $3.89 | $2.72 | Yes | |
| LTC2938HMS#TRPBF | MS-12 | H | $2.78 | Yes | ||
| LTC2938IDE#PBF | 4x3 DFN-12 | I | $3.53 | $2.47 | Yes | |
| LTC2938IDE#TRPBF | 4x3 DFN-12 | I | $2.53 | Yes | ||
| LTC2938IMS#PBF | MS-12 | I | $3.53 | $2.47 | Yes | |
| LTC2938IMS#TRPBF | MS-12 | I | $2.53 | 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
- Desktop and Notebook Computers
- Multivoltage Systems
- Telecom Equipment
- Network Servers
- Automotive Control Systems
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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.
