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STMicroelectronics LE45ABD
- Part No.:
- LE45ABD
- Manufacturer:
- STMicroelectronics
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LE45ABD.pdf
- Description:
- IC REG LINEAR 4.5V 100MA 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:4,213
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Product details
Overview
LE45ABD from STMicroelectronics is a very low dropout (LDO) linear voltage regulator delivering 4.5 V ±1% output at up to 100 mA, featuring 0.2 V typical dropout voltage, 50 µA quiescent current in OFF mode, and TTL-compatible inhibit control for power sequencing in battery-powered systems.
For engineers reviewing the LE45ABD datasheet, LE45ABD pinout, LE45ABD application, or LE45ABD equivalent, this device supports precision local regulation with thermal/overcurrent protection, minimal external capacitance (2.2 µF), and operation across –40 °C to 125 °C junction temperature - critical for portable instrumentation, automotive body electronics, and industrial sensor nodes.
Technical Context
The LE45ABD integrates an internal pass transistor, precision voltage reference, error amplifier, and logic-controlled inhibit circuit enabling ON/OFF toggling via TTL-level input on Pin 5 (SO-8 package). Its architecture eliminates need for external biasing or feedback resistors.
It employs internal current limiting and thermal shutdown, with supply voltage rejection of 79 dB at 120 Hz and 74 dB at 1 kHz. The SO-8 variant uses pins 2, 3, 6, and 7 tied to the die attach flag for enhanced thermal dissipation (RthJA = 55 °C/W).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 4.5 V ±1% at 25 °C; maintains regulation over full load (0–100 mA) and temperature (–40 to 125 °C) |
| Dropout Voltage | 0.2 V typ. @ 100 mA; enables stable 4.5 V output from as low as 4.7 V input |
| Quiescent Current | 0.5 mA typ. in ON mode (no load); 50 µA in OFF mode - extends battery life in standby |
| Supply Voltage Rejection | 79 dB @ 120 Hz; suppresses ripple from noisy DC-DC stages feeding the LDO |
| Stability Capacitance | 2.2 µF ceramic output capacitor sufficient; reduces PCB area and BOM cost vs. legacy regulators |
| Operating Temperature | –40 °C to +125 °C junction range; qualified for under-hood automotive and industrial environments |
| Inhibit Logic Threshold | VIL ≤ 0.8 V, VIH ≥ 2.0 V; compatible with standard 3.3 V/5 V microcontroller GPIO without level-shifting |
Pinout & Package
LE45ABD is available in SO-8 package with exposed die attach flag (pins 2, 3, 6, 7 internally connected) for improved thermal performance. TO-92 variant is also offered but LE45ABD specifically denotes the SO-8 version per ST order code conventions ('D' suffix indicates SO-8).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 | VOUT | Regulated 4.5 V output; connects directly to load and bypass capacitor |
| Pin 2 | GND / Flag | Ground reference and thermal path; electrically tied to pins 3, 6, 7 for low RthJA |
| Pin 3 | GND / Flag | Secondary ground terminal tied to die attach flag; enhances heatsinking on PCB copper pour |
| Pin 4 | VIN | Input supply (up to 18 V); requires local 0.1 µF ceramic decoupling |
| Pin 5 | INH (Inhibit) | TTL-compatible enable/disable control; <0.8 V = OFF, >2.0 V = ON |
| Pin 6 | GND / Flag | Third ground/flag connection; improves thermal conduction to PCB |
| Pin 7 | GND / Flag | Fourth ground/flag terminal; enables uniform heat spreading across package bottom |
| Pin 8 | NC | No connect; left unconnected per datasheet - not internally bonded |
Key Features
| Feature | Design Value |
|---|---|
| Very low dropout | 0.2 V typ. @ 100 mA enables use with single-cell Li-ion (3.0–4.2 V) or tight-input systems |
| TTL inhibit control | Pin 5 accepts standard logic levels - simplifies integration with MCU GPIO for dynamic power gating |
| ±1% output accuracy | Guaranteed over temperature and line/load; eliminates need for post-regulation trimming in precision analog rails |
| Internal protection | Thermal shutdown and current limiting prevent damage during overload or ambient overheating |
| Low-noise operation | 50 µV RMS output noise (10 Hz–100 kHz) supports sensitive ADCs, sensors, and RF front-ends |
Applications
| Portable Medical Sensors | Automotive Body Control Modules |
|---|---|
|
Use Scenario: Powering low-power ECG front-end ICs and MEMS accelerometers in wearable monitors. IC Role / Device Role: Local 4.5 V rail generator with fast enable/disable for duty-cycled sensing. Use Value: 50 µA OFF-mode current extends coin-cell life beyond 2 years; 0.2 V dropout allows operation down to 4.7 V battery voltage. |
Use Scenario: Supplying microcontrollers and CAN transceivers in door modules and seat controllers. IC Role / Device Role: Inhibit-controlled LDO for selective subsystem power-down during sleep mode. Use Value: –40 °C to 125 °C rating ensures reliability in engine bay proximity; 79 dB SVR rejects alternator ripple. |
| Industrial IoT Edge Nodes | Smart Metering Subsystems |
|
Use Scenario: Regulating power for LoRaWAN transceivers and environmental sensors in battery-operated gateways. IC Role / Device Role: Primary 4.5 V supply with thermal protection during extended transmit bursts. Use Value: Internal current limit prevents latch-up during RF PA surge loads; 2.2 µF stability enables compact 0402 capacitor layout. |
Use Scenario: Providing clean 4.5 V bias to metrology ADCs and real-time clocks in electricity meters. IC Role / Device Role: Precision low-noise regulator for analog signal chain integrity. Use Value: ±1% output tolerance ensures consistent ADC reference scaling; 50 µV noise avoids digitization errors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LE45C | ±2% output tolerance; same SO-8 package and electrical specs except accuracy | Suitable where cost sensitivity outweighs precision requirements (e.g., non-critical digital rails) | Select LE45C if ±2% VO drift is acceptable and budget constraints dominate design priorities |
| LDL1145 | 4.5 V fixed output, 200 mA capability, 120 mV dropout, 30 µA IQ in shutdown | Better efficiency in ultra-low-power always-on circuits; smaller SOT-23-5 footprint | Choose LDL1145 when higher current headroom or lower quiescent current is required in space-constrained layouts |
Compared with LE45C, LE45ABD offers tighter output accuracy for analog-sensitive systems; versus LDL1145, it trades higher IQ and lower current for proven thermal robustness in SO-8 and broader industrial temperature support.
Availability
LE45ABD is available at Aetrix Electronics and suitable for portable medical sensors, automotive body control modules, and industrial IoT edge nodes requiring stable component supply with long-term manufacturability and automotive-grade qualification.
Supply support for LE45ABD 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and automotive-grade analog devices.
The LE series LDOs were developed for high-reliability, low-power embedded systems demanding precision regulation, wide temperature operation, and integrated power-control logic - especially in battery-constrained and thermally demanding environments.
FAQ
What is the maximum input voltage for LE45ABD?
The absolute maximum DC input voltage is 20 V, but the recommended operating range is up to 18 V. Exceeding 18 V risks exceeding thermal limits under load, especially at high ambient temperatures. The device's internal protection will activate before catastrophic failure, but sustained operation above 18 V is not specified or guaranteed.
Can LE45ABD be used without the inhibit function?
Yes - when Pin 5 (INH) is grounded or pulled below 0.8 V, the device remains disabled; when left open or tied to VIN, it defaults to ON mode. However, ST recommends grounding Pin 5 if unused to prevent noise-induced toggling, as floating inputs may cause erratic regulation or increased quiescent current.
Is an input capacitor required for stability?
A 0.1 µF ceramic capacitor is required between VIN and GND, placed as close as possible to Pins 4 and 2. This minimizes high-frequency impedance and prevents oscillation due to PCB trace inductance. Omitting it may cause instability under transient load conditions or elevated temperatures.
Does LE45ABD support reverse polarity protection?
No - LE45ABD lacks internal reverse-voltage protection. Applying reverse polarity to VIN or VOUT can damage the IC. External protection (e.g., series Schottky diode or MOSFET-based ideal diode) must be added if system-level reverse input is possible, such as during hot-swap or dual-supply configurations.
LE45ABD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 18V
- Voltage - Output (Min/Fixed):
- 4.5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.5V @ 100mA
- Current - Output:
- 100mA
- Current - Quiescent (Iq):
- 1 mA
- Current - Supply (Max):
- 3 mA
- PSRR:
- 77dB ~ 60dB (120Hz ~ 10kHz)
- Control Features:
- Enable
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
LE45ABD FAQ
1.How can I place an order for LE45ABD through Aetrix?
Please submit a Request for Quotation (RFQ) for LE45ABD 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 LE45ABD reliable?
The price and inventory of LE45ABD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LE45ABD is usually 5 days.
3.What payment methods are accepted for LE45ABD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LE45ABD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LE45ABD?
LE45ABD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LE45ABD 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 LE45ABD?
For technical support, including LE45ABD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LE45ABD requirements.
6.How does Aetrix verify that LE45ABD is sourced from the original manufacturer or authorized distributors?
All LE45ABD 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 LE45ABD meets industry standards.
7.What is the process for return or replacement of LE45ABD?
All LE45ABD units undergo pre-shipment inspection (PSI). If there is an issue with LE45ABD, 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 LE45ABD part is unused and in its original packaging.
Return procedure for LE45ABD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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