Overview
The L4973D3.3-013TR from STMicroelectronics is a high-performance step-down switching regulator designed to deliver up to 3.5 A of output current. This monolithic power switching regulator is available in fixed output voltages of 3.3 V and 5.1 V, with the option for adjustable outputs ranging from 0.5 V to 50 V. Realized in BCD mixed technology, the L4973 uses an internal power D-MOS transistor to achieve high efficiency and fast switching times.
The device features a wide input voltage range from 8 V to 55 V, making it suitable for a variety of applications. It includes advanced features such as pulse-by-pulse current limiting, hiccup mode for short circuit protection, voltage feed forward regulation, soft-start, input/output synchronization, and protection against feedback loop disconnection and thermal shutdown.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Input Voltage Range | 8 | - | 55 | V |
| Output Voltage (L4973V3.3) | 3.26 | 3.36 | 3.46 | V |
| Output Voltage (L4973V5.1) | 5.00 | 5.1 | 5.20 | V |
| Maximum Output Current | - | - | 3.5 | A |
| Switching Frequency | 90 | 100 | 110 | kHz |
| RDS(on) | 0.15 | 0.22 | 0.35 | Ω |
| Efficiency (VO = 5.1 V, IO = 3.5 A) | - | 90 | - | % |
| Efficiency (VO = 3.3 V, IO = 3.5 A) | - | 85 | - | % |
| Maximum Power Dissipation | - | - | 4 | W |
| Junction Temperature Range | -40 | - | 150 | °C |
Key Features
- Up to 3.5 A step-down converter
- Operating input voltage range from 8 V to 55 V
- Fixed output voltages of 3.3 V and 5.1 V, with adjustable outputs from 0.5 V to 50 V
- Frequency adjustable up to 300 kHz
- Voltage feed forward regulation
- Zero load current operation (minimum 1 mA)
- Internal current limiting (pulse by pulse and HICCUP mode)
- Precise 5.1 V reference voltage externally available
- Input/output synchronization function
- Inhibit for zero current consumption
- Protection against feedback disconnection and thermal shutdown
- Output overvoltage protection
- Soft-start function
Applications
The L4973D3.3-013TR is suitable for a wide range of applications, including but not limited to:
- Industrial power supplies
- Automotive systems
- Telecommunication equipment
- Medical devices
- Consumer electronics requiring high-efficiency power conversion
Q & A
- What is the maximum output current of the L4973D3.3-013TR?
The maximum output current is up to 3.5 A.
- What is the input voltage range of the L4973D3.3-013TR?
The input voltage range is from 8 V to 55 V.
- What are the fixed output voltages available for the L4973D3.3-013TR?
The fixed output voltages are 3.3 V and 5.1 V.
- Can the output voltage be adjusted?
- What is the maximum switching frequency of the L4973D3.3-013TR?
The maximum switching frequency is up to 300 kHz.
- Does the L4973D3.3-013TR have built-in protection features?
- How does the inhibit function work?
The inhibit function allows the device to enter a sleep mode with zero current consumption by applying a high logic signal to the INH pin.
- What is the typical RDS(on) of the internal D-MOS transistor?
The typical RDS(on) is 0.15 Ω.
- What is the efficiency of the L4973D3.3-013TR at full load?
The efficiency is up to 90% for a 5.1 V output and up to 85% for a 3.3 V output, both at 3.5 A load.
- What package type is available for the L4973D3.3-013TR?
The device is available in an SO-20 package for surface mount assembly.
