LTC1625 - No RSENSE Current Mode Synchronous Step-Down Switching Regulator
Features
- Highest Efficiency Current Mode Controller
- No Sense Resistor Required
- Stable High Current Operation
- Dual N-Channel MOSFET Synchronous Drive
- Wide VIN Range: 3.7V to 36V
- Wide VOUT Range: 1.19V to VIN
- ±1% 1.19V Reference
- Programmable Fixed Frequency with Injection Lock
- Very Low Drop Out Operation: 99% Duty Cycle
- Forced Continuous Mode Control Pin
- Optional Programmable Soft Start
- Pin Selectable Output Voltage
- Foldback Current Limit
- Output Overvoltage Protection
- Logic Controlled Micropower Shutdown: IQ < 30µA
- Available in 16-Lead Narrow SSOP and SO Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC1625 is a synchronous step-down switching regulator controller that drives external N-Channel power MOSFETs using few external components. Current mode control with MOSFET VDS sensing eliminates the need for a sense resistor and improves efficiency. The frequency of a nominal 150kHz internal oscillator can be synchronized to an external clock over a 1.5:1 frequency range.Burst Mode operation at low load currents reduces switching losses and low dropout operation extends operating time in battery-powered systems. A forced continuous mode control pin can assist secondary winding regulation by disabling Burst Mode operation when the main output is lightly loaded.
Fault protection is provided by foldback current limiting and an output overvoltage comparator. An external capacitor attached to the RUN/SS pin provides soft start capability for supply sequencing. A wide supply range allows operation from 3.7V (3.9V for LTC1625I) to 36V at the input and 1.19V to VIN at the output.
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 |
|---|---|---|---|---|---|
| LTC1625CGN#PBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LTC1625CGN#TRPBF | SSOP-16 | GN | C | 05-08-1641 (GN16) | Yes |
| LTC1625CS#PBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LTC1625CS#TRPBF | SO-16 | S | C | 05-08-1610 (S16) | Yes |
| LTC1625IGN#PBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LTC1625IGN#TRPBF | SSOP-16 | GN | I | 05-08-1641 (GN16) | Yes |
| LTC1625IS#PBF | SO-16 | S | I | 05-08-1610 (S16) | Yes |
| LTC1625IS#TRPBF | SO-16 | S | I | 05-08-1610 (S16) | 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 | |
|---|---|---|---|---|---|---|
| LTC1625CGN#PBF | SSOP-16 | C | $5.80 | $4.90 | Yes | |
| LTC1625CGN#TRPBF | SSOP-16 | C | $4.96 | Yes | ||
| LTC1625CS#PBF | SO-16 | C | $5.45 | $4.55 | Yes | |
| LTC1625CS#TRPBF | SO-16 | C | $4.61 | Yes | ||
| LTC1625IGN#PBF | SSOP-16 | I | $7.02 | $5.90 | Yes | |
| LTC1625IGN#TRPBF | SSOP-16 | I | $5.96 | Yes | ||
| LTC1625IS#PBF | SO-16 | I | $6.75 | $5.50 | Yes | |
| LTC1625IS#TRPBF | SO-16 | I | $5.56 | 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 |
|---|---|---|---|
| DC2008A | LTC1625IGN Demo Board | 4.5V ≤ VIN ≤ 28V; VOUT = 3.3V @ 15A | Contact Factory | |
| 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 | |
|---|---|---|---|---|---|---|
| LTC1625IGN#PBF | SSOP-16 | I | $7.02 | $5.90 | Yes | |
| LTC1625IGN#TRPBF | SSOP-16 | I | $5.96 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- Notebook and Palmtop Computers, PDAs
- Cellular Telephones and Wireless Modems
- Battery Chargers
- Distributed Power
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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
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Models for the following parts are available in LTspice:
LTC1625
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.
