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STMicroelectronics LD2982BM18R
- Part No.:
- LD2982BM18R
- Manufacturer:
- STMicroelectronics
- Package:
- SC-74A, SOT-753
- Datasheet:
-
LD2982BM18R.pdf
- Description:
- IC REG LINEAR 1.8V 50MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,049
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Product details
Overview
LD2982BM18R from STMicroelectronics is a 50 mA, 1.8 V fixed-output low-dropout linear regulator with TTL-compatible inhibit control, 120 mV dropout at 50 mA, 30 µVRMS output noise (with 10 nF bypass capacitor), and SOT23-5L package - designed for noise-sensitive, battery-powered applications such as mobile audio subsystems and portable microcontroller core supplies.
For engineers reviewing the LD2982BM18R datasheet, LD2982BM18R pinout, LD2982BM18R application, or LD2982BM18R equivalent, key selection criteria include ultra-low quiescent current (<1 µA in shutdown), ±1% output voltage tolerance at 25°C, compatibility with low-ESR ceramic capacitors down to 1 µF, and thermal performance up to 125°C junction temperature.
Technical Context
The LD2982BM18R employs a PNP pass transistor architecture enabling ultra-low dropout (7 mV at 1 mA, 120 mV at 50 mA) and minimal load-dependent regulation shift. Its internal feedback network uses laser-trimmed resistors (R1 = 42.6 kΩ, R2 = 51.15 kΩ) to achieve ±1% initial accuracy over temperature.
Shutdown is implemented via a dedicated INHIBIT pin (Pin 3) with TTL-compatible thresholds (VIL ≤ 0.15 V, VIH ≥ 2 V); pulling INHIBIT low reduces quiescent current to <1 µA while maintaining reverse-current blocking (no body diode between IN and OUT).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.8 V ±1% at 25°C - ensures stable core supply for 1.8 V logic domains without external trimming. |
| Max Output Current | 50 mA - sufficient for low-power MCU cores, sensors, or RF front-end biasing. |
| Dropout Voltage | 120 mV at 50 mA - enables operation from 1.92 V input, critical for single-cell Li-ion or Li-poly systems. |
| Quiescent Current | 375 µA typ. at 50 mA load; <1 µA in shutdown - extends battery life in always-on standby modes. |
| Output Noise | 30 µVRMS (300 Hz–50 kHz, with 10 nF CBYP) - meets stringent noise requirements for ADC references or audio DAC supplies. |
| PSRR | 45 dB at 1 kHz - suppresses ripple from noisy switching supplies feeding the LDO input. |
| Stability Capacitor | 1 µF ceramic (X7R) - enables compact layout without tantalum or electrolytic components. |
Pinout & Package
SOT23-5L - 5-pin surface-mount package (2.8 × 1.75 × 1.3 mm), RoHS-compliant, ECOPACK® certified, optimized for high-density PCB layouts and automated assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (IN) | Input supply connection | Accepts 2.5–16 V DC; requires local 1 µF ceramic decoupling within 12.7 mm of pin. |
| 2 (GND) | Analog ground reference | Must connect to clean analog ground plane; shared return path for IN, OUT, and Bypass. |
| 3 (INHIBIT) | Logic-controlled enable/disable | TTL-compatible; drives regulator OFF when ≤0.15 V; must not float - tie to VI if unused. |
| 4 (Bypass) | Noise reduction node | Connects 10 nF ceramic capacitor to GND to reduce thermal noise to 30 µVRMS. |
| 5 (OUT) | Regulated output | Delivers 1.8 V ±1% to load; requires 2.2 µF ceramic capacitor (low-ESR) for stability per spec. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low dropout | 7 mV at 1 mA load - sustains regulation even as battery discharges below 2.0 V. |
| Sub-µA shutdown current | <1 µA quiescent draw in inhibit mode - preserves energy in long-duration sleep states. |
| Low-noise design | 30 µVRMS output noise with 10 nF bypass - eliminates need for post-regulation filtering in precision analog stages. |
| Reverse current blocking | No conduction from OUT to IN when VOUT > VIN - prevents backfeed in multi-rail systems. |
| Thermal protection | Internal junction temperature limit with foldback current limiting - ensures safe operation under overload or ambient extremes. |
Applications
| Mobile Audio Codec Supply | Low-Power MCU Core Rail |
|---|---|
|
Use Scenario: Powering stereo audio DAC/ADC in Bluetooth earbuds with single-cell Li-ion (2.7–4.2 V). IC Role / Device Role / Timing Role: Primary low-noise 1.8 V supply for analog signal chain and digital interface logic. Use Value: 30 µVRMS noise and 45 dB PSRR prevent audible hiss and clock feedthrough into audio output. |
Use Scenario: Supplying ARM Cortex-M0+ core and SRAM in wearable health sensor node. IC Role / Device Role / Timing Role: Always-on LDO delivering regulated 1.8 V during active sensing and sub-µA shutdown during deep sleep. Use Value: <1 µA shutdown current extends 200 mAh coin-cell lifetime beyond 3 years in intermittent-sampling mode. |
| Camera Module I/O Interface | Portable Medical Sensor Bias |
|
Use Scenario: Providing clean 1.8 V I/O voltage for MIPI CSI-2 interface in compact action camera. IC Role / Device Role / Timing Role: Local point-of-load regulator decoupled from noisy main PMIC rail. Use Value: 120 mV dropout allows direct regulation from 2.0 V intermediate rail, minimizing heat and board area. |
Use Scenario: Biasing low-power ECG front-end amplifier and SAR ADC in handheld diagnostic device. IC Role / Device Role / Timing Role: Precision analog supply isolated from digital switching noise. Use Value: ±1% output tolerance and low drift ensure consistent gain calibration across -40°C to 85°C operating range. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-noise, low-IQ LDO applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS78018DRVR | Lower IQ (500 nA typical), but higher dropout (200 mV at 50 mA) and no bypass pin for noise reduction. | Preferred for ultra-long-life coin-cell devices where noise is secondary to IQ. | Select when sub-µA shutdown dominates over noise performance and board space permits larger dropout margin. |
| MCP1702T-1802E/MB | Higher noise (80 µVRMS), no inhibit pin, ±2% tolerance, but wider input range (up to 13.2 V). | Suitable for cost-sensitive industrial sensors where 1.8 V accuracy and noise are less critical. | Choose when system lacks dedicated shutdown control and tolerates looser output regulation. |
Compared with TPS78018DRVR and MCP1702T-1802E/MB, the LD2982BM18R uniquely balances ultra-low noise, precise ±1% output, and integrated inhibit control in the smallest SOT23-5L footprint - making it optimal for space-constrained, battery-powered audio and sensing nodes requiring both low power and high signal integrity.
Availability
LD2982BM18R is available at Aetrix Electronics and suitable for portable medical diagnostics, wireless audio peripherals, embedded sensor nodes, and low-power IoT edge devices requiring stable component supply across extended product lifecycles.
Supply support for LD2982BM18R 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, analog chips, and MEMS sensors for industrial, automotive, and consumer markets.
The LD2982 series belongs to ST's precision low-dropout regulator product line, engineered specifically for ultra-low-noise, low-quiescent-current power delivery in portable and battery-operated equipment.
FAQ
What is the minimum input voltage required for stable 1.8 V output at 50 mA?
The LD2982BM18R requires an input voltage ≥1.92 V to maintain regulation at 50 mA load, based on its 120 mV maximum dropout specification. At lighter loads (e.g., 1 mA), input can be as low as 1.807 V due to 7 mV typical dropout. Operation below these thresholds causes unregulated output collapse.
Can the INHIBIT pin be left unconnected if shutdown functionality is not needed?
No - the INHIBIT pin must never be left floating. If shutdown is unused, it must be hard-wired to the IN pin (VI) to ensure reliable ON-state operation. Floating INHIBIT may cause erratic enable/disable behavior due to lack of internal pull-up.
Is a bypass capacitor mandatory for achieving 30 µVRMS noise performance?
Yes - the 30 µVRMS noise figure is measured with a 10 nF ceramic capacitor connected between the Bypass pin and GND. Omitting this capacitor increases output noise to approximately 120 µVRMS, as confirmed in the electrical characteristics table.
Does the LD2982BM18R support reverse current protection when VOUT exceeds VIN?
Yes - the device uses a PNP pass transistor without an inherent body diode, preventing reverse current flow from OUT to IN. When VOUT > VIN, only leakage through internal feedback resistors flows to GND (typ. 160 µA), eliminating backfeed risks in multi-supply systems.
LD2982BM18R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 16V
- Voltage - Output (Min/Fixed):
- 1.8V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.225V @ 50mA
- Current - Output:
- 50mA
- Current - Quiescent (Iq):
- 150 µA
- Current - Supply (Max):
- 1.2 mA
- PSRR:
- 45dB (1kHz)
- Control Features:
- Enable
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
LD2982BM18R FAQ
1.How can I place an order for LD2982BM18R through Aetrix?
Please submit a Request for Quotation (RFQ) for LD2982BM18R 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 LD2982BM18R reliable?
The price and inventory of LD2982BM18R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD2982BM18R is usually 5 days.
3.What payment methods are accepted for LD2982BM18R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD2982BM18R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LD2982BM18R?
LD2982BM18R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LD2982BM18R 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 LD2982BM18R?
For technical support, including LD2982BM18R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD2982BM18R requirements.
6.How does Aetrix verify that LD2982BM18R is sourced from the original manufacturer or authorized distributors?
All LD2982BM18R 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 LD2982BM18R meets industry standards.
7.What is the process for return or replacement of LD2982BM18R?
All LD2982BM18R units undergo pre-shipment inspection (PSI). If there is an issue with LD2982BM18R, 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 LD2982BM18R part is unused and in its original packaging.
Return procedure for LD2982BM18R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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