Overview
The LD1117S12CTR is a low drop voltage regulator produced by STMicroelectronics. This device is capable of providing up to 800 mA of output current and is available in both fixed and adjustable versions. The fixed version of the LD1117S12CTR offers an output voltage of 1.2 V, while other fixed versions provide output voltages of 1.8 V, 2.5 V, 3.3 V, and 5.0 V. The adjustable version has a reference voltage (VREF) of 1.25 V. The regulator is available in several package types, including SOT-223, DPAK, SO-8, and TO-220, with the SOT-223 and DPAK packages optimizing thermal characteristics and offering space-saving benefits.
The LD1117S12CTR features high efficiency due to its NPN pass transistor, which ensures that the quiescent current flows mostly into the load. Stability is achieved with a minimum 10 μF capacitor. On-chip trimming allows for a tight output voltage tolerance of ± 1% at 25 °C. The adjustable version is pin-to-pin compatible with other standard adjustable voltage regulators, maintaining better performance in terms of dropout voltage and tolerance.
Key Specifications
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| Output Voltage (VO) | 1.188 | 1.20 | 1.212 | V |
| Output Current (IO) | 0 | 800 | 950 | mA |
| Line Regulation (∆VO) | 0.035 | 0.2 | % | |
| Load Regulation (∆VO) | 0.1 | 0.4 | % | |
| Temperature Stability (∆VO) | 0.5 | % | ||
| Operating Input Voltage (Vin) | 15 | V | ||
| Quiescent Current (Id) | 5 | 10 | mA | |
| Dropout Voltage (Vd) | 1 | 1.1 | V | |
| Supply Voltage Rejection (SVR) | 60 | 75 | dB | |
| Thermal Resistance Junction-Case (RthJC) | 15 | °C/W | ||
| Thermal Resistance Junction-Ambient (RthJA) | 110 | °C/W |
Key Features
- Low dropout voltage (1 V typ.)
- Output current up to 800 mA
- Fixed output voltage of: 1.2 V, 1.8 V, 2.5 V, 3.3 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 through on-chip trimming
Applications
The LD1117S12CTR is suitable for a variety of applications, including:
- Communications equipment
- Computers and peripherals
- Industrial equipment
- Personal electronics
Its low dropout voltage and high current capability make it particularly useful in portable applications where space and efficiency are critical.
Q & A
- What is the maximum output current of the LD1117S12CTR?
The maximum output current of the LD1117S12CTR is up to 800 mA.
- What are the available output voltages for the fixed versions of the LD1117?
The fixed versions of the LD1117 offer output voltages of 1.2 V, 1.8 V, 2.5 V, 3.3 V, and 5.0 V.
- What is the reference voltage for the adjustable version of the LD1117?
The reference voltage (VREF) for the adjustable version of the LD1117 is 1.25 V.
- What is the typical dropout voltage of the LD1117S12CTR?
The typical dropout voltage of the LD1117S12CTR is 1 V.
- What type of transistor is used in the LD1117S12CTR for high efficiency?
The LD1117S12CTR uses an NPN pass transistor for high efficiency.
- What is the minimum capacitor required for stability?
A minimum 10 μF capacitor is required for stability.
- What is the thermal resistance junction-case (RthJC) for the SOT-223 package?
The thermal resistance junction-case (RthJC) for the SOT-223 package is 15 °C/W.
- What is the supply voltage rejection (SVR) of the LD1117S12CTR?
The supply voltage rejection (SVR) of the LD1117S12CTR is typically 75 dB.
- What are the common applications of the LD1117S12CTR?
The LD1117S12CTR is commonly used in communications equipment, computers and peripherals, industrial equipment, and personal electronics.
- What are the available package types for the LD1117S12CTR?
The LD1117S12CTR is available in SOT-223, DPAK, SO-8, and TO-220 packages.
