BETAFixed output3.3 V nominal
Fixed 3.3 V LDO regulator
LM1117-3.3 Specifications
Review LM1117-3.3 electrical specifications, operating conditions and package details.
Package view
Key specifications
The fixed-output feedback divider is inside the package. External capacitors and a good thermal path complete the supply.
Rated output current800 mA · thermal limits apply
Operating junction0–125 °C · selected LM1117 grade
Output capacitor≥ 10 µF tantalum · check ESR
Package details
LM1117T-3.3/NOPB · TO-220
| Property | Details |
|---|---|
| Manufacturer | Texas Instruments |
| Part number | LM1117T-3.3/NOPB |
| Package | TO-220 |
| Connections | 3 pins |
| Mounting | Through-hole |
| Lead pitch | 2.54 mm |
| Package code | NDE |
| Thermal reference | Board and heatsink dependent; see TI SNOS412Q |
Operating characteristics
TI LM1117-3.3 · fixed-output grade
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Nominal output | 3.3 V | Fixed 3.3 V option |
| Output at 25°C | 3.267 / 3.3 / 3.333 V | Minimum / typical / maximum; VIN = 5 V, IOUT = 10 mA |
| Output across specified conditions | 3.235–3.365 V | 0–800 mA; VIN = 4.75–10 V; TJ = 0–125°C |
| Output current | Up to 800 mA | Requires headroom and adequate thermal design |
| Junction operating range | 0–125°C | Selected LM1117 grade |
| Recommended input maximum | 15 V | Must also satisfy thermal and dropout constraints |
No specifications match. Try a parameter name or a unit.
The LM1117I grade has a different temperature range. This reference follows the selected non-I devices.
Regulation and supply current
Retain the measurement conditions
Manufacturer specifications 5 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Line regulation | 1 mV typical; 6 mV maximum | IOUT = 0 mA, VIN = 4.75–15 V; typical at 25°C, maximum over 0–125°C |
| Load regulation | 1 mV typical; 10 mV maximum | VIN = 4.75 V, IOUT = 0–800 mA; typical at 25°C, maximum over 0–125°C |
| Ground current | 5 mA typical; 10 mA maximum | VIN ≤ 15 V; typical at 25°C, maximum over 0–125°C |
| Dropout criterion | Output falls by 100 mV | Referenced to VOUT measured with VIN = VOUT + 1.5 V |
| Current limiting | Built in | An overload protection feature, not an extra operating-current allowance |
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Dropout changes with output current and junction temperature; use TI’s table and curves when choosing the supply margin.
Capacitors and stability
Capacitance and ESR both matter
Manufacturer specifications 5 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input bypass | 10 µF tantalum | TI’s suitable input capacitor for most applications |
| Output capacitor | At least 10 µF tantalum | Required for the selected fixed-output circuit |
| Output capacitor ESR | 0.3–22 Ω | Manufacturer stability guidance |
| Low-ESR substitution | Check before changing technology | A ceramic capacitor is not automatically a valid drop-in replacement |
| Placement | Short input, output and ground paths | Keep the load return and regulator ground well connected |
No specifications match. Try a parameter name or a unit.
Check capacitance, ESR, voltage rating and temperature behavior for the actual capacitor part.
5 V to 3.3 V example
100 mA nominal resistive load
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Supply | Regulated 5 V DC | Feed pin 3 INPUT |
| Return | Pin 1 GND | Common with input supply, capacitors and load |
| Output | Pin 2 OUTPUT | Nominal 3.3 V; tab is the same net |
| Example load | 33 Ω · at least 1 W | 3.3 / 33 = 0.10 A; resistor power = 0.33 W |
| Pass-stage loss | 0.17 W | (5 − 3.3) × 0.10 |
| Including typical ground current | Approximately 0.195 W | 0.17 + 5 × 0.005 |
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These are nominal calculations, not measured results. Output tolerance and actual ground current change the values.
Thermal and stress limits
Package ratings require a thermal context
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Power estimate | PD ≈ (VIN − VOUT) × ILOAD + VIN × IGND | Include both loss terms |
| Junction estimate | TJ ≈ TA + PD × RθJA | Only for the board and airflow represented by the thermal resistance |
| TO-220 RθJA / RθJC(bottom) | 23.8 / 1.5°C/W | TI thermal characterization conditions |
| D²PAK RθJA / RθJC(bottom) | 41.3 / 1.3°C/W | TI thermal characterization conditions |
| Input absolute maximum | 20 V | Stress rating, not the recommended operating maximum |
| Junction absolute maximum | 150°C | Recommended operation ends at 125°C |
| Storage range | −65 to +150°C | Unpowered |
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The output-connected tab must not be shorted to a grounded heatsink. Thermal shutdown does not replace cooling design.
Connections by function
Select a pin for its function, connection guidance and electrical notes.