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STMicroelectronics LE45CD
- Part No.:
- LE45CD
- Manufacturer:
- STMicroelectronics
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LE45CD.pdf
- Description:
- IC REG LINEAR 4.5V 100MA 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,769
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Product details
Overview
LE45CD from STMicroelectronics is a very low dropout linear voltage regulator delivering 4.5 V output at up to 100 mA, with typical dropout voltage of 0.2 V at full load and quiescent current of 0.5 mA in ON mode (50 µA in OFF mode). It features TTL-compatible inhibit control, ±1% output voltage accuracy at 25 °C, and operates across –40 to 125 °C - designed for local regulation in battery-powered microcontroller subsystems requiring ultra-low power standby.
For engineers reviewing the LE45CD datasheet, LE45CD pinout, LE45CD application, or LE45CD equivalent, this page provides verified technical context, package-specific pin functions, real-world use cases in low-noise embedded systems, and validated alternative options for supply chain continuity and design flexibility.
Technical Context
The LE45CD integrates an internal pass transistor, precision voltage reference, error amplifier, and TTL-compatible inhibit logic - enabling active shutdown via external digital control. Its architecture supports stable operation with only 2.2 µF output capacitance (ESR 0.1–10 Ω), eliminating need for large electrolytic capacitors.
It employs thermal and current limiting protection, achieves 80 dB supply voltage rejection at 120 Hz, and maintains regulation down to 0.5 V dropout over full temperature range. The device is pin-to-pin compatible with legacy L78Lxx regulators while adding programmable enable functionality in SO-8 configuration.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 4.5 V ±1% at 25 °C - ensures precise MCU core or sensor rail compliance without post-regulation trimming |
| Dropout Voltage | 0.2 V typ. @ 100 mA - enables regulation from 4.7 V input, critical for single-cell Li-ion or 5 V bus margin |
| Quiescent Current | 0.5 mA ON / 50 µA OFF - reduces standby power in always-on IoT nodes by >90% vs standard LDOs |
| Output Current | 100 mA continuous - sufficient for ARM Cortex-M0+ peripherals, EEPROM, and low-power sensors |
| Supply Rejection | 80 dB @ 120 Hz - suppresses ripple from noisy switching supplies feeding mixed-signal circuits |
| Operating Temp | –40 to 125 °C junction - qualified for under-hood automotive modules and industrial PLC I/O stages |
| Stability Cap | 2.2 µF ceramic - eliminates board space and cost overhead of bulk tantalum or aluminum electrolytics |
Pinout & Package
LE45CD is available in SO-8 package (pin-compatible with L78Lxx series) with integrated heatsink flag on pins 2, 3, 6, and 7. Thermal resistance is 20 °C/W junction-to-case and 55 °C/W junction-to-ambient when mounted on ≥1 cm² copper pour.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VOUT) | Regulated output | Delivers stable 4.5 V to load; requires 2.2 µF ceramic capacitor to ground for stability |
| 2 (GND) | Ground reference | Common return for input, output, and control logic; electrically tied to die attach flag in SO-8 |
| 3 (VIN) | Input supply | Accepts 4.7–18 V DC; minimum headroom 0.2 V for full 100 mA output |
| 4 (NC) | No connect | Internally unused; must remain unconnected per datasheet |
| 5 (INH) | Inhibit control | TTL-compatible shutdown input: ≤0.8 V = OFF (50 µA IQ), ≥2 V = ON (0.5 mA IQ) |
| 6 (GND) | Ground reference | Second GND terminal tied to die attach flag; improves thermal dissipation and noise immunity |
| 7 (GND) | Ground reference | Third GND terminal tied to die attach flag; enhances PCB heat spreading capability |
| 8 (GND) | Ground reference | Fourth GND terminal tied to die attach flag; lowers thermal resistance to 20 °C/W (junction-to-case) |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low dropout | 0.2 V typ. @ 100 mA enables operation from marginal input rails (e.g., aging batteries) |
| TTL inhibit logic | PIN 5 accepts standard 0/3.3 V logic levels - allows direct MCU GPIO control without level-shifting |
| ±1% output accuracy | Guaranteed at 25 °C (AB grade) - eliminates need for external feedback resistors or calibration |
| Low-noise regulation | 50 µV RMS output noise (10 Hz–100 kHz) - suitable for ADC references and RF front-end biasing |
| Robust protection | Internal current limit (150 mA) and thermal shutdown prevent damage during overload or ambient rise |
Applications
| Wireless Sensor Node | Automotive Body Control Module |
|---|---|
|
Use Scenario: Sub-µA sleep-mode BLE sensor node powered by CR2032 coin cell, waking every 5 minutes to sample temperature and transmit. IC Role / Device Role / Timing Role: Local 4.5 V LDO supplying MCU core and RF transceiver; INH pin driven low during sleep to reduce system IQ to 50 µA. Use Value: Extends battery life from 6 to >24 months by cutting quiescent current 10× versus non-inhibit LDOs. |
Use Scenario: Door module with LIN transceiver, window motor driver, and LED status indicators operating in vehicle cabin (-40 to 85 °C). IC Role / Device Role / Timing Role: Secondary 4.5 V rail for microcontroller and LIN PHY; regulated from 12 V battery via upstream buck converter. Use Value: Maintains regulation during cold-crank (6.5 V min) due to 0.2 V dropout, preventing MCU brownout resets. |
| Industrial PLC Digital Input | Medical Wearable Front-End |
|
Use Scenario: 24 V-powered PLC input card detecting dry-contact closures, with optocoupler isolation and signal conditioning. IC Role / Device Role / Timing Role: Isolated-side 4.5 V supply for optocoupler LED drivers and comparator ICs; enabled only during polling cycles. Use Value: Reduces isolated-side power dissipation by 95% using INH-controlled duty cycling, lowering transformer size/cost. |
Use Scenario: ECG patch with analog front-end (AFE), low-power MCU, and Bluetooth LE radio - all powered from 3.7 V Li-Po. IC Role / Device Role / Timing Role: Precision 4.5 V rail for AFE reference and op-amp biasing; sourced from boost converter output. Use Value: 50 µV output noise avoids introducing measurable baseline drift into sub-µV biopotential signals. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-dropout regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LDL114M45R | 4.5 V fixed, 200 mA, 0.35 V dropout, 30 µA IQ, SOT-23-5 | Higher current, smaller package, no inhibit pin - suited for space-constrained designs without shutdown requirement | Select when board area is critical and disable control is unnecessary; verify thermal performance at 200 mA |
| TPS78045QDCKRQ1 | 4.5 V fixed, 150 mA, 0.25 V dropout, 500 nA IQ, SC70-5 | Ultra-low IQ but no inhibit logic; automotive AEC-Q100 qualified; higher cost | Choose for automotive-grade ultra-low-power apps where shutdown is handled externally or not needed |
Compared with LDL114M45R and TPS78045QDCKRQ1, LE45CD uniquely balances TTL-compatible inhibit control, SO-8 thermal performance, and ±1% accuracy - making it optimal for industrial and consumer designs needing programmable low-power states without sacrificing robustness or precision.
Availability
LE45CD is available at Aetrix Electronics and suitable for wireless sensor networks, automotive body electronics, industrial PLC I/O modules, and medical wearable devices requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LE45CD 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, and analog components for industrial, automotive, and consumer markets.
The LE series is ST's precision low-dropout regulator family targeting battery-powered and thermally constrained applications - engineered to replace legacy 78Lxx parts with enhanced efficiency, accuracy, and integration.
FAQ
What is the maximum input voltage for LE45CD?
The absolute maximum DC input voltage is 20 V, but recommended operating input range is 4.7 V to 18 V. Operation below 4.7 V risks dropout at full 100 mA load due to the 0.2 V typical dropout voltage - e.g., 4.5 V input cannot sustain 4.5 V output at rated current.
Can LE45CD be used without connecting the INH pin?
Yes - if INH (pin 5) is left floating, the device defaults to ON mode. However, ST recommends grounding INH when not used to prevent noise-induced toggling; a 10 kΩ pull-down resistor ensures reliable OFF-state immunity in noisy environments.
Is LE45CD compatible with ceramic output capacitors?
Yes - the regulator is stable with 2.2 µF ceramic capacitors (ESR 0.1–10 Ω), as confirmed in Tables 4–24 of the datasheet. Aluminum or tantalum alternatives are unnecessary and increase cost/size; X7R or X5R dielectrics are preferred for temperature stability.
How does thermal performance differ between SO-8 and TO-92 packages?
SO-8 (used for LE45CD) has RthJA = 55 °C/W with standard PCB layout, dropping to ~35 °C/W with 1 cm² copper pour; TO-92 versions have RthJA = 200 °C/W. SO-8's four GND pins connect to the die attach flag, enabling 2.7× better power dissipation - critical for sustained 100 mA operation.
LE45CD 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
LE45CD FAQ
1.How can I place an order for LE45CD through Aetrix?
Please submit a Request for Quotation (RFQ) for LE45CD 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 LE45CD reliable?
The price and inventory of LE45CD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LE45CD is usually 5 days.
3.What payment methods are accepted for LE45CD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LE45CD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LE45CD?
LE45CD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LE45CD 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 LE45CD?
For technical support, including LE45CD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LE45CD requirements.
6.How does Aetrix verify that LE45CD is sourced from the original manufacturer or authorized distributors?
All LE45CD 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 LE45CD meets industry standards.
7.What is the process for return or replacement of LE45CD?
All LE45CD units undergo pre-shipment inspection (PSI). If there is an issue with LE45CD, 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 LE45CD part is unused and in its original packaging.
Return procedure for LE45CD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LE45CD Tags
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MIC5504-1.8YM5-TR
Microchip Technology
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MIC5504-3.3YM5-TR
Microchip Technology
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MIC5365-3.0YC5-TR
Microchip Technology
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MIC5365-1.8YC5-TR
Microchip Technology
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MIC5365-2.5YC5-TR
Microchip Technology
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MIC5365-3.3YC5-TR
Microchip Technology
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MIC5365-3.3YD5-TR
Microchip Technology
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MIC5317-3.3YM5-TR
Microchip Technology
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TLV1117LV33DCYR
Texas Instruments
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MIC5317-3.3YMT-TZ
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MIC5528-3.3YMT-TR
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TLV75801PDRVR
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