Overview
The L4976 is a step-down monolithic power switching regulator produced by STMicroelectronics. It delivers up to 1 A of current at output voltages adjustable between 3.3 V and 50 V, selected by a simple external divider. The device is realized in BCD mixed technology and utilizes an internal power D-MOS transistor with a typical Rds(ON) of 0.25 Ω, ensuring high efficiency and high switching speed. The regulator operates with an input voltage range of 8 V to 55 V and supports switching frequencies up to 300 kHz. Key features include pulse-by-pulse current limiting, hiccup mode for short circuit protection, voltage feedforward regulation, protection against feedback loop disconnection, and thermal shutdown.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Operating Input Voltage Range | 8 | - | 55 | V |
| Output Voltage Range | 3.3 | - | 50 | V |
| Maximum Output Current | - | 1 | - | A |
| Switching Frequency | 90 | 100 | 110 | kHz |
| Reference Voltage | 5.0 | 5.1 | 5.2 | V |
| Maximum Duty Cycle | 95 | 97 | - | % |
| Thermal Shutdown Temperature | - | - | 150 | °C |
| Maximum Power Dissipation (SO16W) | - | - | 0.8 | W |
Key Features
- Pulse-by-pulse current limiting and hiccup mode for short circuit protection
- Voltage feedforward regulation
- Protection against feedback loop disconnection
- Thermal shutdown
- Internal power D-MOS transistor with a typical Rds(ON) of 0.25 Ω for high efficiency and high switching speed
- Adjustable switching frequency up to 300 kHz
- Zero load current operation
- Precise 5.1 V reference voltage with 20 mA current capability
Applications
The L4976 is suitable for a wide range of applications requiring efficient and reliable DC-DC conversion. These include:
- Power supplies for industrial and consumer electronics
- Embedded systems and IoT devices
- Automotive systems
- Telecommunication equipment
- Medical devices requiring stable and efficient power regulation
Q & A
- What is the maximum output current of the L4976?
The maximum output current of the L4976 is 1 A. - What is the input voltage range of the L4976?
The input voltage range of the L4976 is from 8 V to 55 V. - How is the output voltage of the L4976 adjusted?
The output voltage of the L4976 is adjusted using a simple external divider. - What is the typical switching frequency of the L4976?
The typical switching frequency of the L4976 is 100 kHz, but it can be adjusted up to 300 kHz. - What protection features does the L4976 have?
The L4976 includes pulse-by-pulse current limiting, hiccup mode for short circuit protection, protection against feedback loop disconnection, and thermal shutdown. - What is the reference voltage of the L4976?
The reference voltage of the L4976 is 5.1 V with a 20 mA current capability. - What are the package options for the L4976?
The L4976 is available in plastic dual in-line (DIP8) and SO16W for SMD assembly. - What is the maximum power dissipation for the SO16W package?
The maximum power dissipation for the SO16W package is 0.8 W. - What is the thermal shutdown temperature of the L4976?
The thermal shutdown temperature of the L4976 is up to 150°C. - How does the L4976 achieve high efficiency?
The L4976 achieves high efficiency through the use of an internal power D-MOS transistor with a typical Rds(ON) of 0.25 Ω.
