LT1528 - 3A Low Dropout Regulator for Microprocessor Applications
Features
- Dropout Voltage: 0.6V at Iout = 3A
- Fast Transient Response
- Output Current: 3A
- Quiescent Current: 400µA
- No Protection Diodes Needed
- Fixed Output Voltage: 3.3V
- Controlled Quiescent Current in Dropout
- Shutdown IQ = 125µA
- Stable with 3.3µF Output Capacitor
- Reverse Battery Protection
- No Reverse Output Current
- Thermal Limiting
Typical Application
Description
The LT1528 is a 3A low dropout regulator optimized to handle the large load current transients associated with the current generation of microprocessors. This device has the fastest transient response of currently available PNP regulators and is very tolerant of variations incapacitor ESR. Dropout voltage is 75mV at 10mA, rising to 300mV at 1A and 600mV at 3A. The device has a quiescent current of 400µA. Quiescent current is well controlled; it does not increase significantly as the device enters dropout. The regulator can operate with output capacitors as small as 3.3µF, although larger capacitors will be needed to achieve the performance required in most microprocessor applications. The LT1528 is available with a fixed output voltage of 3.3V. An external SENSE pin allows adjustment to output voltages greater than 3.3V, using a simple resistive divider. This allows the device to be adjusted over a wide range of output voltages, including the 3.3V to 4.2V range required by a variety of processors from Intel, IBM, AMD, and Cyrix.The LT1528 has both reverse input and reverse output protection and includes a shutdown feature. Quiescent current drops to 125µA in shutdown. The LT1528 is available in 5-lead TO-220 and 5-lead DD-PAK packages.
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 |
|---|---|---|---|---|---|
| LT1528CQ#PBF | DDPAK-5 | Q | C | 05-08-1461 | Yes |
| LT1528CQ#TRPBF | DDPAK-5 | Q | C | 05-08-1461 | Yes |
| LT1528CT#PBF | TO-220 | T | C | 05-08-1421 (Standard) | 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 | |
|---|---|---|---|---|---|---|
| LT1528CQ#PBF | DDPAK-5 | C | $4.75 | $3.80 | Yes | |
| LT1528CQ#TRPBF | DDPAK-5 | C | $3.92 | Yes | ||
| LT1528CT#PBF | TO-220 | C | $4.35 | $3.50 | 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
- Microprocessor Applications
- Post Regulator for Switching Supplies
- 5V to 3.3V Logic Regulator
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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:
LT1528
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.
