LT2940 - Power and Current Monitor
Features
- Four-Quadrant Power Measurement
- ±5% Power Measurement Accuracy
- 4V to 80V High Side Sense, 100V Max
- Current Mode Power and Current Outputs
- Output Bandwidth Exceeds 500kHz
- ±3% Current Measurement Accuracy
- 6V to 80V Supply Range, 100V Max
- Inverting and Noninverting Open-Collector Comparator Outputs
- Available in 12-Pin DFN (3mm × 3mm) and 12-Lead MSOP Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LT2940 measures a high side current and a differential voltage, multiplies them and outputs a current proportional to instantaneous power. Bidirectional high side currents and bipolar voltage differences are correctly handled by the four-quadrant multiplier and push-pull output stage, which allows the LT2940 to indicate forward and reverse power flow.
An integrated comparator with inverting and noninverting open-collector outputs makes the LT2940 a complete power level monitor. In addition, an output current proportional to the sensed high side current allows current monitoring. The current mode outputs make scaling, filtering and time integration as simple as selecting external resistors and/or capacitors.
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 |
|---|---|---|---|---|---|
| LT2940CDD#PBF | 3x3 DFN-12 | DD | C | 05-08-1725 | Yes |
| LT2940CDD#TRPBF | 3x3 DFN-12 | DD | C | 05-08-1725 | Yes |
| LT2940CMS#PBF | MS-12 | MS | C | 05-08-1668 | Yes |
| LT2940CMS#TRPBF | MS-12 | MS | C | 05-08-1668 | Yes |
| LT2940IDD#PBF | 3x3 DFN-12 | DD | I | 05-08-1725 | Yes |
| LT2940IDD#TRPBF | 3x3 DFN-12 | DD | I | 05-08-1725 | Yes |
| LT2940IMS#PBF | MS-12 | MS | I | 05-08-1668 | Yes |
| LT2940IMS#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 | |
|---|---|---|---|---|---|---|
| LT2940CDD#PBF | 3x3 DFN-12 | C | $2.93 | $2.05 | Yes | |
| LT2940CDD#TRPBF | 3x3 DFN-12 | C | $2.11 | Yes | ||
| LT2940CMS#PBF | MS-12 | C | $2.93 | $2.05 | Yes | |
| LT2940CMS#TRPBF | MS-12 | C | $2.11 | Yes | ||
| LT2940IDD#PBF | 3x3 DFN-12 | I | $3.51 | $2.46 | Yes | |
| LT2940IDD#TRPBF | 3x3 DFN-12 | I | $2.52 | Yes | ||
| LT2940IMS#PBF | MS-12 | I | $3.51 | $2.46 | Yes | |
| LT2940IMS#TRPBF | MS-12 | I | $2.52 | 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 |
|---|---|---|---|
| DC1495A | LT2940| Power & Current Monitor | $25.00 | |
| 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 | |
|---|---|---|---|---|---|---|
| LT2940IMS#PBF | MS-12 | I | $3.51 | $2.46 | Yes | |
| LT2940IMS#TRPBF | MS-12 | I | $2.52 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Board Level Power and Current Monitoring
- Line Card and Server Power Monitoring
- Power Sense Circuit Breaker
- Power Control Loops
- Power/Energy Meters
- Battery Charger Metering
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Design Tools
LTspice
LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice
Models for the following parts are available in LTspice:
LT2940
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.
