LTC1871 - Wide Input Range, No RSENSE Current Mode Boost, Flyback and SEPIC Controller
Features
- High Efficiency (No Sense Resistor Required)
- Wide Input Voltage Range: 2.5V to 36V
- Current Mode Control Provides Excellent Transient Response
- High Maximum Duty Cycle (92% Typ)
- ±2% RUN Pin Threshold with 100mV Hysteresis
- ±1% Internal Voltage Reference
- Micropower Shutdown: IQ = 10μA
- Programmable Operating Frequency (50kHz to 1MHz) with One External Resistor
- Synchronizable to an External Clock Up to 1.3 × fOSC
- User-Controlled Pulse Skip or Burst Mode® Operation
- Internal 5.2V Low Dropout Voltage Regulator
- Output Overvoltage Protection
- Capable of Operating with a Sense Resistor for High Output Voltage Applications
- Small 10-Lead MSOP Package
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC1871 is a wide input range, current mode, boost, flyback or SEPIC controller that drives an N-channel power MOSFET and requires very few external components. Intended for low to medium power applications, it eliminates the need for a current sense resistor by utilizing the power MOSFET’s on-resistance, thereby maximizing efficiency.
The IC’s operating frequency can be set with an external resistor over a 50kHz to 1MHz range, and can be synchronized to an external clock using the MODE/SYNC pin. Burst Mode operation at light loads, a low minimum operating supply voltage of 2.5V and a low shutdown quiescent current of 10μA make the LTC1871 ideally suited for battery-operated systems.
For applications requiring constant frequency operation, Burst Mode operation can be defeated using the MODE/ SYNC pin. Higher output voltage boost, SEPIC and flyback applications are possible with the LTC1871 by connecting the SENSE pin to a resistor in the source of the power MOSFET.
The LTC1871 is available in the 10-lead MSOP package.
| Vin Range | INTVcc | Features | |
| LTC1871 | 2.5V to 36V | 5.2V | - |
| LTC1871-1 | 2.5V to 36V | 5.2V | Lower Burst Mode Threshold (0.195V vs. 0.3V) |
| LTC1871-7 | 6V to 36V | 7V | Drives 6V Gate N-Channel MOSFETs |
| LTC1871X | 2.5V to 36V | 5.2V | 175°C Junction Temp, 100% Tested at 175°C |
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 |
|---|---|---|---|---|---|
| LTC1871EMS#PBF | MS-10 | MS | E | 05-08-1661 | Yes |
| LTC1871EMS#TRPBF | MS-10 | MS | E | 05-08-1661 | Yes |
| LTC1871HMS#PBF | MS-10 | MS | H | 05-08-1661 | Yes |
| LTC1871HMS#TRPBF | MS-10 | MS | H | 05-08-1661 | Yes |
| LTC1871IMS#PBF | MS-10 | MS | I | 05-08-1661 | Yes |
| LTC1871IMS#TRPBF | MS-10 | MS | I | 05-08-1661 | 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 | |
|---|---|---|---|---|---|---|
| LTC1871EMS#PBF | MS-10 | E | $3.14 | $2.65 | Yes | |
| LTC1871EMS#TRPBF | MS-10 | E | $2.71 | Yes | ||
| LTC1871HMS#PBF | MS-10 | H | $4.83 | $3.38 | Yes | |
| LTC1871HMS#TRPBF | MS-10 | H | $3.44 | Yes | ||
| LTC1871IMS#PBF | MS-10 | I | $4.38 | $3.05 | Yes | |
| LTC1871IMS#TRPBF | MS-10 | I | $3.11 | 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 |
|---|---|---|---|
| DC414B | LTC1871EMS | Boost Controller, 3V ≤ VIN ≤ 5V, Vout = 5V @ 7A | $125.00 | |
| DC415A | LTC1871EMS | High Efficiency SEPIC Converter, 5V-15V Input, 12Vout @ 2Amp | $125.00 | |
| 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 | |
|---|---|---|---|---|---|---|
| LTC1871HMS#PBF | MS-10 | H | $4.83 | $3.38 | Yes | |
| LTC1871HMS#TRPBF | MS-10 | H | $3.44 | Yes | ||
| LTC1871IMS#PBF | MS-10 | I | $4.38 | $3.05 | Yes | |
| LTC1871IMS#TRPBF | MS-10 | I | $3.11 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Telecom Power Supplies
- Portable Electronic Equipment
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Design Tools
LTspice
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Models for the following parts are available in LTspice:
LTC1871
LTC1871-1
LTC1871-7
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.
