Overview
The LD1117S33TR is a low drop voltage regulator produced by STMicroelectronics. It is part of the LD1117 series, which offers both fixed and adjustable output voltage options. This specific model provides a fixed output voltage of 3.3V and is capable of delivering up to 800 mA of output current. The regulator is available in the SOT-223 package, which optimizes thermal characteristics and offers a space-saving design. The LD1117S33TR features high efficiency due to its NPN pass transistor, ensuring that the quiescent current flows mostly into the load. Only a minimum 10 μF capacitor is required for stability, and on-chip trimming allows for a tight output voltage tolerance of ±1% at 25°C.
Key Specifications
| Attribute | Value |
|---|---|
| Input Voltage - Max | 15V |
| Output Voltage Fixed | 3.267V |
| Dropout Voltage - Max | 1.2V |
| Output Current - Max | 1300mA |
| Rated Power | 12W |
| Tolerance (%) | ±1% |
| Operating Temp Range | 0°C to 125°C |
| Regulator Topology | Fixed |
| Quiescent Current | 10mA |
| No. of Outputs | Single |
| Output Noise | 100µV |
| Load Regulation | 10mV |
| Line Regulation | 6mV |
| Package Style | SOT-223 (TO-261-4, SC-73) |
| Mounting Method | Surface Mount |
Key Features
- Low dropout voltage (1 V typ.)
- Output current up to 800 mA
- Fixed output voltage of 3.3 V (other fixed versions available: 1.2 V, 1.8 V, 2.5 V, 2.85 V, 3.0 V, 5.0 V)
- Adjustable version availability (VREF = 1.25 V)
- Internal current and thermal limit
- Available in ± 1 % (at 25 °C) and 2 % in full temperature range
- Supply voltage rejection: 75 dB (typ.)
- High efficiency due to NPN pass transistor
- Minimum 10 μF capacitor required for stability
- Tight output voltage tolerance due to on-chip trimming
Applications
The LD1117S33TR is suitable for a variety of applications requiring stable and efficient voltage regulation. Some key applications include:
- Power supply systems in electronic devices
- Active termination for SCSI-2 lines (especially the 2.85 V version)
- Embedded systems and IoT devices
- Automotive and industrial control systems
- Consumer electronics requiring low dropout voltage regulation
Q & A
- What is the maximum output current of the LD1117S33TR?
The LD1117S33TR can provide up to 800 mA of output current.
- What is the fixed output voltage of the LD1117S33TR?
The fixed output voltage of the LD1117S33TR is 3.3 V.
- What is the maximum input voltage for the LD1117S33TR?
The maximum input voltage for the LD1117S33TR is 15 V.
- What is the dropout voltage of the LD1117S33TR?
The dropout voltage of the LD1117S33TR is 1.2 V (max).
- What package style is the LD1117S33TR available in?
The LD1117S33TR is available in the SOT-223 package.
- What is the operating temperature range of the LD1117S33TR?
The operating temperature range of the LD1117S33TR is from 0°C to 125°C.
- Does the LD1117S33TR have internal current and thermal limits?
Yes, the LD1117S33TR has internal current and thermal limits.
- What is the supply voltage rejection of the LD1117S33TR?
The supply voltage rejection of the LD1117S33TR is 75 dB (typ.).
- Is the LD1117S33TR available in adjustable versions?
Yes, the LD1117 series includes adjustable versions with VREF = 1.25 V.
- What type of transistor is used in the LD1117S33TR for high efficiency?
The LD1117S33TR uses an NPN pass transistor for high efficiency.
