BETARegulated output+5 V nominal
Fixed +5 V low-dropout regulator
LM2940T-5 Specifications
Review LM2940T-5 electrical specifications, operating conditions and package details.
Package view
Key specifications
A regulated +5 V rail with three electrical connections.
Selected C-grade range0–125 °C · see manufacturer conditions
Current class1 A · thermal limits apply
Connections3 IN 1 · GND 2 · OUT 3
Package details
LM2940CT-5.0/NOPB · TO-220
| Property | Details |
|---|---|
| Manufacturer | Texas Instruments |
| Part number | LM2940CT-5.0/NOPB |
| Package | TO-220 |
| Connections | 3 pins |
| Mounting | Through-hole |
| Lead pitch | 2.54 mm |
| Package code | V |
| Thermal reference | Check the manufacturer package and mounting conditions |
Package connections
Front view, marking toward you
Manufacturer specifications 3 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| 1 · INPUT | Feeds the series pass stage. | Apply +7.5 V and fit 0.47 µF local input bypass. |
| 2 · GND | Metal tab is electrically GND. | Join supply return, load and capacitor returns. |
| 3 · OUTPUT | Supplies nominal +5 V within regulation and thermal limits. | Connect the load and 22 µF to ground. |
No specifications match. Try a parameter name or a unit.
The exposed tab duplicates pin 2. Verify polarity before applying power.
Operating characteristics
LM2940CT-5.0/NOPB / LM2940CS-5.0/NOPB
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Output at 25°C | 4.85–5.15 V | 5 mA–1 A; specified input range |
| Output across stated range | 4.75–5.25 V | 5 mA–1 A; selected C grade |
| Input for 5 V regulation specification | 6.25–26 V | More specific than family headline |
| Load regulation | 35 mV typical; 50 mV max | 50 mA–1 A; LM2940C |
| Ground current at 1 A | 30 mA typical; 45 mA max at 25°C | VIN = VOUT + 5 V; 60 mA max over temperature |
| Output noise | 150 µV RMS typical | 10 Hz–100 kHz; 5 mA |
| Ripple rejection | 72 dB typical; 60 dB min | 120 Hz; 100 mA; LM2940C |
No specifications match. Try a parameter name or a unit.
Read the exact test conditions. Typical values are not guaranteed limits.
Capacitors and connections
Local components near the regulator
Manufacturer specifications 5 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input bypass | 0.47 µF | IN 1 to GND 2 |
| Output capacitor | 22 µF | OUT 3 to GND 2 |
| Capacitor selection | At least 22 µF, ESR 0.1–1 Ω | Maintain effective capacitance and ESR across temperature |
| Tab / thermal pad | GND | Electrically connected to pin 2 |
| Dropout | 0.5 V typical; 0.8 V max at 1 A, 25°C; 1 V max over temperature | Not an unconditional fixed input margin |
No specifications match. Try a parameter name or a unit.
Short return paths and correct capacitor characteristics matter.
Basic circuit and readings
100 mA nominal DC load
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input / output | +7.5 V / +5 V | DC source with sufficient headroom |
| Load | 50 Ω | Dissipation 0.50 W; choose adequate derating |
| Current | 5 V / 50 Ω = 0.10 A | Nominal calculation |
| Pass loss | 0.25 W | (7.5 − 5) V × 0.10 A |
| Total regulator loss | Pass loss + |VIN| × IGND | Ground current also produces heat |
| Cooling | TJ ≈ TA + PD × θJA | Use thermal resistance for actual mounting |
No specifications match. Try a parameter name or a unit.
Respect resistor rating, input ripple and regulator dissipation.
Package and stress reference
LM2940CT-5.0/NOPB · TO-220
Manufacturer specifications 5 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Lead pitch | 2.54 mm | Through-hole |
| Selected temperature grade | 0–125°C | LM2940C; other LM2940-N grades differ |
| Input stress limit | 26 V operating maximum; see transient limits | Do not use stress limits as a normal design target |
| Storage | −65 to +150°C | Unpowered |
| Package mapping | 1 INPUT; 2 GND; 3 OUTPUT | Thermal pad duplicates pin 2 |
No specifications match. Try a parameter name or a unit.
Verify the manufacturer package drawing and footprint before PCB manufacture.
Connections by function
Select a pin for its function, connection guidance and electrical notes.