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Specifications
SKU: 4626176
Below is the parameter table and instructions for the LD1117AS33, a 3.3V Low Dropout Linear Regulator.
LD1117AS33 Parameter Table
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Input Voltage | ( V_ ) | 4.5 | - | 15 | V |
| Output Voltage | ( V_ ) | 3.3 | 3.3 | 3.3 | V |
| Output Current | ( I_ ) | - | 800 | 1000 | mA |
| Dropout Voltage | ( V_ ) | - | 1.2 | 1.3 | V |
| Quiescent Current | ( I_Q ) | - | 5 | 10 | mA |
| Shutdown Current | ( I_ ) | - | 2 | 5 | μA |
| Line Regulation | - | - | 0.01 | 0.02 | %/V |
| Load Regulation | - | - | 0.01 | 0.02 | %/mA |
| Output Noise Voltage | - | - | 30 | 50 | μVrms |
| Thermal Resistance (Junction to Ambient) | ( R_{theta JA} ) | - | 65 | 100 | °C/W |
| Operating Temperature | ( T_ ) | -40 | - | 125 | °C |
| Storage Temperature | ( T_ ) | -65 | - | 150 | °C |
Instructions for Using LD1117AS33
Circuit Design:
- Input Capacitor: Place a 10μF tantalum or ceramic capacitor close to the input pin to ensure stability and filter out high-frequency noise.
- Output Capacitor: Use a 10μF tantalum or ceramic capacitor at the output to stabilize the output voltage and reduce ripple. For better transient response, a 0.1μF ceramic capacitor can be added in parallel.
- Bypass Capacitors: Additional bypass capacitors may be necessary if the regulator is far from the power source or if the load has high-frequency components.
Thermal Management:
- Ensure adequate heat dissipation by using a heatsink or a PCB with sufficient copper area. The thermal resistance of the package should be considered to prevent overheating.
- For continuous operation at high current, calculate the power dissipation (( P_D = (V_ - V_) times I_ )) and ensure that the junction temperature does not exceed 125°C.
PCB Layout:
- Keep the traces between the input and output capacitors and the regulator as short as possible to minimize inductance and improve stability.
- Use wide traces for the input and output paths to reduce resistance and improve current handling.
- Place the regulator on the top layer of the PCB for better heat dissipation.
Power-On Sequence:
- Ensure that the input voltage rises smoothly and does not exceed the maximum input voltage rating.
- If the circuit includes other components, consider the power-on sequence to avoid inrush currents that could damage the regulator.
Testing:
- Measure the output voltage under various load conditions to ensure it remains within the specified tolerance.
- Check the temperature of the regulator under maximum load conditions to ensure it does not overheat.
- Verify the line and load regulation by measuring the output voltage while varying the input voltage and load current.
By following these instructions, you can ensure reliable and efficient operation of the LD1117AS33 in your design.
(For reference only)Inquiry - LD1117AS33
