Overview
The L4973D3.3 is a step-down monolithic power switching regulator produced by STMicroelectronics. This device delivers up to 3.5 A of current at fixed output voltages of 3.3 V or 5.1 V, with the capability to adjust the output voltage up to 50 V using a simple external divider. Realized in BCD mixed technology, the L4973 uses an internal power D-MOS transistor with a typical RDS(on) of 0.15 Ω, ensuring high efficiency and fast switching times. The regulator operates over a wide input voltage range from 8 V to 55 V and supports switching frequencies up to 300 kHz, making it suitable for a variety of applications.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Output Current | Up to 3.5 A | A |
| Fixed Output Voltages | 3.3 V, 5.1 V (±1%) | V |
| Adjustable Output Voltages | 0.5 V to 50 V (3.3 type), 5.1 V to 50 V (5.1 type) | V |
| Input Voltage Range | 8 V to 55 V | V |
| Switching Frequency | Up to 300 kHz | kHz |
| Package Types | DIP-18, SO20 | |
| Operating Temperature | -40°C to 125°C | °C |
| Efficiency | 85% to 90% | % |
| Thermal Resistance (Junction-Pin) | 12°C/W (DIP-18), 15°C/W (SO-20) | °C/W |
Key Features
- Inhibit for zero current consumption (100 mA typ. at VCC = 24 V)
- Input/output synchronization function
- Thermal shutdown
- Protection against feedback disconnection
- Soft-start function
- Output over voltage protection
- Internal current limiting (pulse by pulse and HICCUP mode)
- Zero load current operation (min. 1 mA)
- Voltage feed forward regulation
- Precise 5.1 V (1.5%) reference voltage externally available
Applications
The L4973D3.3 is versatile and can be used in a wide range of applications, including but not limited to:
- Industrial power supplies
- Automotive systems
- Telecommunication equipment
- Medical devices
- Consumer electronics requiring high-efficiency DC-DC conversion
Q & A
- What is the maximum output current of the L4973D3.3? The maximum output current is up to 3.5 A.
- What are the fixed output voltages available for the L4973D3.3? The fixed output voltages are 3.3 V and 5.1 V (±1%).
- What is the adjustable output voltage range for the L4973D3.3? The adjustable output voltage range is from 0.5 V to 50 V for the 3.3 V type and from 5.1 V to 50 V for the 5.1 V type.
- What is the input voltage range for the L4973D3.3? The input voltage range is from 8 V to 55 V.
- What is the maximum switching frequency of the L4973D3.3? The maximum switching frequency is up to 300 kHz.
- What types of packages are available for the L4973D3.3? The available packages are DIP-18 and SO20.
- What is the operating temperature range for the L4973D3.3? The operating temperature range is from -40°C to 125°C.
- What are the key protection features of the L4973D3.3? Key protection features include thermal shutdown, protection against feedback disconnection, output over voltage protection, and internal current limiting.
- Does the L4973D3.3 support zero load current operation? Yes, it supports zero load current operation with a minimum of 1 mA.
- Is the L4973D3.3 efficient in terms of power conversion? Yes, it has an efficiency range of 85% to 90%.
