Overview
The L78L33ACZTR 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. With adequate heat-sinking, they can deliver up to 100 mA of output current. The L78L series is intended for fixed voltage regulation in various applications, including local or on-card regulation to eliminate noise and distribution issues associated with single-point regulation. They can also be used with power pass elements to create high-current voltage regulators and as replacements for Zener diode/resistor combinations, offering improvements in quiescent current and noise reduction.
Key Specifications
| Parameter | Test Conditions | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|---|
| Output Voltage | TJ = 25 °C | 3.168 | 3.3 | 3.432 | V |
| Output Voltage | IO = 1 to 40 mA, VI = 5.3 to 20 V | 3.135 | 3.465 | V | |
| Line Regulation | VI = 5.4 to 20 V, TJ = 25 °C | 150 mV | mV | ||
| Load Regulation | IO = 1 to 100 mA, TJ = 25 °C | 60 mV | mV | ||
| Quiescent Current | TJ = 25 °C | 6 mA | mA | ||
| Quiescent Current Change | IO = 1 to 40 mA | 0.2 mA | mA | ||
| Output Noise Voltage | B = 10 Hz to 100 kHz, TJ = 25 °C | 70 µV | µV | ||
| Supply Voltage Rejection | VI = 12 to 23 V, f = 120 Hz, IO = 40 mA, TJ = 25 °C | 37 to 44 dB | dB | ||
| Dropout Voltage | 1.7 V | V | |||
| Maximum Output Current | 100 mA | mA | |||
| Operating Temperature Range | -40 | 125 | °C |
Key Features
- Output current up to 100 mA
- Output voltages of 3.3 V (for L78L33ACZTR)
- Internal current limiting and thermal shutdown for robust operation
- Short-circuit protection
- No external components required
- Available in ± 4% (A) or ± 8% (C) selection
- Low quiescent current and low noise
- Can be used as Zener diode/resistor combination replacements
- Available in TO-92, SO-8, and SOT-89 packages
Applications
- Local or on-card voltage regulation to eliminate noise and distribution problems
- High-current voltage regulators when used with power pass elements
- Replacement for Zener diode/resistor combinations
- Industrial applications requiring reliable and robust voltage regulation
- Embedded systems and electronic devices needing stable voltage supply
Q & A
- What is the maximum output current of the L78L33ACZTR?
The maximum output current is up to 100 mA.
- What are the available output voltages for the L78L series?
The L78L series offers output voltages of 3.3, 5, 6, 8, 9, 10, 12, 15, 18, and 24 V.
- What kind of protection does the L78L33ACZTR have?
The L78L33ACZTR has internal current limiting, thermal shutdown, and short-circuit protection.
- Do I need external components to use the L78L33ACZTR?
No, the L78L33ACZTR does not require any external components.
- What is the operating temperature range for the L78L33ACZTR?
The operating temperature range is from -40 °C to 125 °C.
- What are the typical quiescent current and dropout voltage for the L78L33ACZTR?
The typical quiescent current is 6 mA, and the dropout voltage is 1.7 V.
- Can the L78L33ACZTR be used in high-current applications?
Yes, it can be used with power pass elements to create high-current voltage regulators.
- What are the available packages for the L78L series?
The L78L series is available in TO-92, SO-8, and SOT-89 packages.
- How does the L78L33ACZTR improve over Zener diode/resistor combinations?
The L78L33ACZTR offers lower quiescent current and lower noise compared to Zener diode/resistor combinations.
- What is the supply voltage rejection ratio for the L78L33ACZTR?
The supply voltage rejection ratio is 37 to 44 dB at 120 Hz.
