My Inquiry
My Account
Texas Instruments LM2940CSX-9.0
- Part No.:
- LM2940CSX-9.0
- Manufacturer:
- Texas Instruments
- Package:
- TO-263-4, D2PAK (3 Leads + Tab), TO-263AA
- Datasheet:
-
LM2940CSX-9.0.pdf
- Description:
- IC REG LIN 9V 1A DDPAK/TO263-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,767
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM2940CSX-9.0 from Texas Instruments is a 1A low-dropout linear voltage regulator delivering a fixed 9.0V output with typical dropout voltage of 0.5V at 1A load, reverse battery protection, and internal short-circuit/thermal shutdown. It operates over 0°C to 125°C and is qualified for automotive and industrial power rails requiring stable 9V supply under line transients.
For engineers reviewing the LM2940CSX-9.0 datasheet, LM2940CSX-9.0 pinout, LM2940CSX-9.0 application, or LM2940CSX-9.0 equivalent, this page provides verified electrical specs, thermal performance data, capacitor stability requirements, and real-world design constraints for vehicular and embedded 9V rail generation.
Technical Context
The LM2940CSX-9.0 uses a PNP pass transistor architecture enabling low dropout and inherent reverse-polarity protection without external diodes. Its quiescent current reduction circuit cuts ground current to 30 mA when input-output differential exceeds ~3V, improving efficiency during normal operation.
It integrates mirror-image insertion protection, load-dump shutdown (for input spikes up to 60V), and internal current limiting (≥1.6A min). Output stability requires ≥22 μF output capacitance with ESR in specified range-critical for transient response in automotive environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 9.0V ±2.7% (8.73V–9.27V) over full temperature and load range-ensures compatibility with 9V logic and analog subsystems. |
| Dropout Voltage | 0.5V typical @ 1A load-enables regulation from 9.5V input, critical for battery-powered systems near end-of-discharge. |
| Output Current | ≥1A continuous-supports high-current peripherals like solenoids, sensors, or microcontroller subsystems without derating. |
| Reverse Battery Protection | Withstands −30V DC input-eliminates need for external blocking diode in automotive 12V systems. |
| Thermal Shutdown Threshold | Junction temperature >125°C triggers shutdown-prevents damage during sustained overload or poor heatsinking. |
| Input Voltage Range | 9.5V to 26V-covers cold-crank (≥9.5V) and load-dump (≤26V) conditions per ISO 7637-2. |
| Quiescent Current | 30 mA max @ 1A load and 5V differential-minimizes standby power loss in always-on vehicle modules. |
Pinout & Package
LM2940CSX-9.0 is packaged in DDPAK/TO-263 (KTT) - a 3-pin surface-mount package with exposed thermal pad. Pin 2 (INPUT) and Pin 7 (GND) are fused to the center DAP; Pin 5 and Pin 6 must be tied together on PCB.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (INPUT) | Unregulated input supply connection | Accepts 9.5–26V; must include local 10μF ceramic bypass capacitor within 10 mm. |
| Pin 2 (GND) | Ground reference and thermal path | Internally fused to DAP; requires direct soldering to ≥1 in² copper pour with ≥6 thermal vias for θJA ≤35°C/W. |
| Pin 3 (OUTPUT) | Regulated 9.0V output | Drives load; requires ≥22 μF output capacitor with controlled ESR (see Fig. 35) placed adjacent to pin. |
Key Features
| Feature | Design Value |
|---|---|
| Reverse battery protection | Withstands −30V DC input without damage-reduces BOM count and failure modes in automotive harnesses. |
| Mirror-image insertion protection | Prevents latch-up or destruction if mounted upside-down-enhances manufacturing robustness in high-volume assembly. |
| Load-dump shutdown | Auto-shutdown during 60V/100ms transients-meets ISO 7637-2 Pulse 5a requirements without external TVS. |
| Low-noise output | 270 μVrms noise (10 Hz–100 kHz)-suitable for analog sensors and precision ADC references without added filtering. |
| Stable with ceramic capacitors | Compatible with low-ESR ceramics when minimum 22 μF is used-enables compact, high-reliability designs. |
Applications
| Automotive Body Control Module (BCM) | Industrial PLC I/O Power Rail |
|---|---|
|
Use Scenario: Powers microcontroller, CAN transceiver, and door-lock actuator drivers from vehicle battery under cold-crank and load-dump conditions. IC Role / Device Role / Timing Role: Primary 9V LDO supplying regulated power to safety-critical control logic and interface ICs. Use Value: Reverse polarity and load-dump protection eliminate need for external protection components, reducing board area by 30% vs discrete solutions. |
Use Scenario: Provides isolated 9V supply for analog input conditioning circuits in programmable logic controllers operating in factory environments. IC Role / Device Role / Timing Role: Stable voltage reference source for 16-bit ADC front-ends and op-amp signal chains. Use Value: Low 270 μVrms noise and <2.7% output tolerance ensure ≤0.5 LSB error in 16-bit measurements across temperature. |
| Telematics Control Unit (TCU) | Off-Highway Equipment Display Backlight Driver |
|
Use Scenario: Supplies 9V to GPS module, cellular modem, and secure boot MCU in connected vehicle gateways with extended temperature operation. IC Role / Device Role / Timing Role: Always-on power domain regulator maintaining RTC and wake-up circuitry during ignition-off states. Use Value: 30 mA quiescent current at 1A load enables >10-year battery backup life in sleep mode without compromising active performance. |
Use Scenario: Powers LED backlight driver ICs in ruggedized displays for construction and agricultural machinery exposed to vibration and wide ambient swings. IC Role / Device Role / Timing Role: Pre-regulator feeding switching LED driver, smoothing input ripple before PWM dimming stage. Use Value: 64 dB ripple rejection at 120 Hz suppresses alternator noise, preventing visible flicker in high-brightness display modes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2940CT-9.0/NOPB | Same electrical specs, but TO-220 (NDE) through-hole package with θJA = 60°C/W (no heatsink required up to 1.2W). | Suitable for prototyping, low-volume industrial controls, or legacy through-hole assemblies where manual rework is preferred. | Select when mechanical mounting flexibility or thermal margin without PCB copper pour is needed. |
| TPS7A4701RGWR | Lower noise (4.5 μVrms), lower dropout (300 mV @ 1A), but no reverse-battery protection and narrower input range (3–36V). | Better for precision analog rails (e.g., audio, RF bias), but requires external reverse-protection diode in automotive use. | Select only for noise-sensitive non-automotive applications where reverse protection is handled elsewhere in the system. |
Compared with LM2940CT-9.0/NOPB, LM2940CSX-9.0 offers superior thermal performance on PCBs with adequate copper area (θJA ≤35°C/W), while TPS7A4701RGWR trades integrated protection for ultra-low noise-making LM2940CSX-9.0 the only drop-in solution for automotive 9V rails needing reverse and load-dump immunity.
Availability
LM2940CSX-9.0 is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power supplies, and telematics control units requiring stable component supply with long lifecycle support and RoHS-compliant packaging.
Supply support for LM2940CSX-9.0 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of automotive-grade qualification expertise and broad power management portfolio.
The LM2940 family was designed specifically for vehicular power systems-delivering robust 1A LDO regulation with built-in protection against reverse battery, load dump, and mirror-image insertion in harsh environments.
FAQ
What is the minimum input voltage required for LM2940CSX-9.0 to maintain regulation?
The LM2940CSX-9.0 requires a minimum input voltage of 9.5V to sustain 9.0V output at full 1A load, based on its 0.5V typical dropout voltage. At lighter loads (e.g., 100 mA), dropout drops to 110 mV, allowing operation down to ~9.11V. Input below 9.5V under full load causes output collapse into dropout region with reduced regulation accuracy.
Can LM2940CSX-9.0 be used without an output capacitor?
No. The LM2940CSX-9.0 requires a minimum 22 μF output capacitor for loop stability, as confirmed in TI's SNVS769I datasheet Figure 35 and Application Information section. Omitting it-or using capacitance below 22 μF-causes oscillation and unregulated output. Ceramic, tantalum, or aluminum electrolytic types may be used if ESR falls within the specified range versus load current.
Does LM2940CSX-9.0 support parallel operation for higher current?
No. The LM2940CSX-9.0 is not designed for parallel operation. Its internal feedback and current-limit architecture do not support current sharing. Attempting to parallel units risks thermal runaway or unequal load distribution. For >1A requirements, select a higher-current LDO or switcher-do not parallel LM2940CSX-9.0 devices.
What is the maximum allowable power dissipation for LM2940CSX-9.0 in a standard PCB layout?
With a 1 in² copper pour and 6 thermal vias under the DAP, LM2940CSX-9.0 achieves θJA ≈ 35°C/W. At 125°C max junction and 85°C ambient, maximum safe power dissipation is (125−85)/35 = 1.14W. This corresponds to ~1.27A at 0.9V dropout (VIN = 9.9V), confirming 1A rating is thermally sustainable in typical automotive PCB layouts.
Is LM2940CSX-9.0 qualified for automotive AEC-Q100?
No. LM2940CSX-9.0 is rated for 0°C to 125°C operation and includes automotive-grade protections (reverse battery, load dump), but it is not AEC-Q100 qualified. For AEC-Q100 compliance, TI offers the pin-compatible LM2940Q-9.0 variant-identifiable by "Q" suffix and documented in separate automotive-grade datasheets.
LM2940CSX-9.0 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- TO-263-4, D2PAK (3 Leads + Tab), TO-263AA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 26V
- Voltage - Output (Min/Fixed):
- 9V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.8V @ 1A
- Current - Output:
- 1A
- Current - Quiescent (Iq):
- 10 mA
- Current - Supply (Max):
- 15 mA
- PSRR:
- 64dB (120Hz)
- Control Features:
- -
- Protection Features:
- Over Current, Over Temperature, Reverse Polarity, Short Circuit
- Operating Temperature:
- 0°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TO-263 (DDPAK-3)
LM2940CSX-9.0 FAQ
1.How can I place an order for LM2940CSX-9.0 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2940CSX-9.0 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LM2940CSX-9.0 reliable?
The price and inventory of LM2940CSX-9.0 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2940CSX-9.0 is usually 5 days.
3.What payment methods are accepted for LM2940CSX-9.0?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2940CSX-9.0 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2940CSX-9.0?
LM2940CSX-9.0 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2940CSX-9.0 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LM2940CSX-9.0?
For technical support, including LM2940CSX-9.0 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2940CSX-9.0 requirements.
6.How does Aetrix verify that LM2940CSX-9.0 is sourced from the original manufacturer or authorized distributors?
All LM2940CSX-9.0 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LM2940CSX-9.0 meets industry standards.
7.What is the process for return or replacement of LM2940CSX-9.0?
All LM2940CSX-9.0 units undergo pre-shipment inspection (PSI). If there is an issue with LM2940CSX-9.0, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LM2940CSX-9.0 part is unused and in its original packaging.
Return procedure for LM2940CSX-9.0:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM2940CSX-9.0 Tags
-
MIC5504-1.8YM5-TR
Microchip Technology
-
MIC5504-3.3YM5-TR
Microchip Technology
-
MIC5365-3.0YC5-TR
Microchip Technology
-
MIC5365-1.8YC5-TR
Microchip Technology
-
MIC5365-2.5YC5-TR
Microchip Technology
-
MIC5365-3.3YC5-TR
Microchip Technology
-
MIC5365-3.3YD5-TR
Microchip Technology
-
MIC5317-3.3YM5-TR
Microchip Technology
-
TLV1117LV33DCYR
Texas Instruments
-
MIC5317-3.3YMT-TZ
Microchip Technology
-
MIC5528-3.3YMT-TR
Microchip Technology
-
TLV75801PDRVR
Texas Instruments
Tech Hub
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
