Overview
The L78L33ABD is a three-terminal positive voltage regulator from STMicroelectronics, part of the L78L series. These regulators are designed to be highly reliable and robust, featuring internal current limiting and thermal shutdown, making them essentially indestructible. They are suitable for a wide range of applications, including local or on-card regulation to eliminate noise and distribution problems associated with single-point regulation. The L78L33ABD is particularly useful as a replacement for Zener diode/resistor combinations, offering improvements in terms of lower quiescent current and lower noise.
Key Specifications
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| Output Voltage | 3.168 | 3.3 | 3.432 | V |
| Output Current | - | - | 100 | mA |
| Line Regulation | - | - | 150 | mV (VI = 5.4 to 20 V, TJ = 25 °C) |
| Load Regulation | - | - | 60 | mV (IO = 1 to 100 mA, TJ = 25 °C) |
| Quiescent Current | - | 6 | 6.5 | mA (TJ = 25 °C) |
| Output Noise Voltage | - | - | 50 | µV (B = 10 Hz to 100 kHz, TJ = 25 °C) |
| Supply Voltage Rejection | - | - | 39 | dB (VI = 9 to 20 V, f = 120 Hz, IO = 40 mA, TJ = 25 °C) |
| Dropout Voltage | - | - | 1.7 | V |
Key Features
- Internal current limiting and thermal shutdown for enhanced reliability and protection.
- No external components required for operation.
- Available in ±4% (A) or ±8% (C) selection.
- Low quiescent current and low noise.
- Can be used as a replacement for Zener diode/resistor combinations.
- Suitable for use with power pass elements to create high-current voltage regulators.
Applications
The L78L33ABD is versatile and can be used in a variety of applications, including:
- Local or on-card voltage regulation to eliminate noise and distribution problems.
- Fixed voltage regulation in various electronic systems.
- High-current voltage regulators when used with power pass elements.
- Replacement for Zener diode/resistor combinations in existing designs.
Q & A
- What is the output voltage of the L78L33ABD? The output voltage of the L78L33ABD is 3.3 V, with a tolerance of ±4% or ±8% depending on the selection.
- What is the maximum output current of the L78L33ABD? The maximum output current is up to 100 mA.
- Does the L78L33ABD require external components for operation? No, the L78L33ABD does not require any external components for operation.
- What are the key protection features of the L78L33ABD? The key protection features include internal current limiting and thermal shutdown.
- What is the quiescent current of the L78L33ABD? The quiescent current is typically 6 mA at 25 °C.
- How does the L78L33ABD perform in terms of noise? The L78L33ABD has low output noise, typically 50 µV over the frequency range of 10 Hz to 100 kHz.
- What is the dropout voltage of the L78L33ABD? The dropout voltage is 1.7 V.
- Can the L78L33ABD be used in high-current applications? Yes, it can be used with power pass elements to create high-current voltage regulators.
- What are some common applications of the L78L33ABD? Common applications include local or on-card voltage regulation, fixed voltage regulation, and as a replacement for Zener diode/resistor combinations.
- What is the operating temperature range of the L78L33ABD? The operating temperature range is from -40 °C to 125 °C for the AB version and 0 °C to 125 °C for the AC version.
