This Product Selection Guide contains information to help select products in the Voltage Regulators - Linear category on DigiKey.com
Linear voltage regulators, including LDO (Low Drop Out) types, are used to provide a stable output voltage that is nominally invariant with respect to changes in load current, input voltage, or environmental factors. Their operating principle requires that the input voltage be maintained above the desired output voltage by some minimum amount, and function on the basis of converting whatever excess voltage is present at the input to heat. While this renders them less efficient than switch-mode voltage regulators for most applications, they are often better suited for applications with high sensitivity to noise.
SelectionCharacteristics
Output Configuration: Indicates the output voltage polarity of the device
Output Type: Indicates which output style the regulator uses, determining its basic characteristics and any necessary external components.
Number of Regulators: The number of instances of a regulator function incorporated within a device.
Voltage - Input (Max): Typically this represents the maximum voltage rating to which a device will meet its given specifications. Exceeding this voltage rating may damage the device and other system components.
Voltage - Output (Min/Fixed): Fir fixed-output regulators, indicates the fixed voltage value the regulator provides on its output terminal. For adjustable devices, indicates the lower boundary of possible voltage values the device offers.
Voltage - Output (Max): For adjustable devices, indicates the upper boundary of possible voltage values the device offers.
Voltage Dropout (Max): Indicates the maximum value of the voltage differential between the part’s input terminal and its output terminal.
Current - Output: The maximum amount of current that can be output by the device.
Current - Quiescent: Characterizes the amount of supply current required to power a device’s internal functions. Measured with no output load and inputs connected to fixed-voltage signals defined by the manufacturer.
Current - Supply (Max): This represents the maximum current to which a device will meet its given specifications. Exceeding this current may damage the device and/or other system components.
PSRR: The device’s power supply rejection ratio, indicating its ability to suppress or eliminate variations in its output voltage relative to its supply voltage.
Control Features: Enumerates the various system control functions the device includes provisions for.
Protection Features: Enumerates the various circuit and device protection features the device includes provisions for.
Operating Temperature: Recommended operating temperature, typically given in a range or as a maximum. Exceeding these temperatures may affect performance or damage the device and other system components.
Mounting Type: Indicates how the device is attached.
Package / Case: Indicates the type of protective case used on an electronic component to allow easy handling, installation, and protection. This selection was determined to be the closest industry standard applicable to the supplier device packaging. Typically it is best to check the actual dimensions from the datasheet rather than depend on this terminology when designing your circuit.
Supplier Device Package: This is what the manufacturer calls the package of this device. They are manufacturer specific. It is typically best to use the actual dimensions from the datasheets rather than to go by this terminology when designing your circuit.
ProductExamples
| MFR PART # | L7805CV |
|---|---|
| DIGIKEY PART # | 497-1443-5-ND |
| MANUFACTURER | STMicroelectronics |
| DESCRIPTION | Linear Voltage Regulator IC Positive Fixed 1 Output 1.5A TO-220 |
| DATASHEET | Click Here |
| MFR PART # | AP2127K-1.8TRG1 |
|---|---|
| DIGIKEY PART # | AP2127K-1.8TRG1DITR-ND - Tape & Reel (TR) |
| MANUFACTURER | Diodes Incorporated |
| DESCRIPTION | Linear Voltage Regulator IC Positive Fixed 1 Output 300mA SOT-23-5 |
| DATASHEET | Click Here |
| MFR PART # | ADP151ACPZ-3.0-R7 |
|---|---|
| DIGIKEY PART # | ADP151ACPZ-3.0-R7TR-ND - Tape & Reel (TR) |
| MANUFACTURER | Analog Devices Inc. |
| DESCRIPTION | Linear Voltage Regulator IC Positive Fixed 1 Output 200mA 6-LFCSP-UD (2x2) |
| DATASHEET | Click Here |
| MFR PART # | TPS79301DBVR |
|---|---|
| DIGIKEY PART # | 296-12154-2-ND - Tape & Reel (TR) |
| MANUFACTURER | Texas Instruments |
| DESCRIPTION | Linear Voltage Regulator IC Positive Adjustable 1 Output 200mA SOT-23-6 |
| DATASHEET | Click Here |
MediaLinks
Videos
Linear Regulator
Articles
Understanding the Advantages and Disadvantages of Linear Regulators
Selecting the Correct Regulator
Basics of LDOs and How to Apply Them Effectively
Linear Regulators Drive Noise Down
Understanding Linear Regulator Noise
Product Training Modules
Selecting the Best Multi-Sourced Linear Reg - TI
DC to DC Conversion Cookbook - STMicroelectronics
Low Dropout Linear Regulator FAQs - ADI
How to Select an Appropriate LDO - Diodes Inc.
Blogs
Introduction to Linear Voltage Regulators
Using Low Quiescent Current LDOs in Wearables
TechForum
My Linear Regulator is Defective!