Micropower, 200 mA Ultra Low-Dropout Fixed or Adjustable Voltage Regulator 8-VSSOP -40 to 125# Technical Documentation: LP2986IMM50NOPB Low-Dropout Voltage Regulator
Manufacturer : NSC (National Semiconductor, now part of Texas Instruments)
Component : LP2986IMM50NOPB
Description : 150 mA, Fixed 5.0 V Output, Ultra-Low-Dropout (ULDO) Voltage Regulator in MSOP-8 Package
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## 1. Application Scenarios
### Typical Use Cases
The LP2986IMM50NOPB is a fixed-output, ultra-low-dropout linear voltage regulator designed for applications requiring stable, low-noise power with minimal input-to-output voltage differential. Its 150 mA output current capability makes it suitable for powering:
- Microcontroller and Microprocessor Core/IO Voltages : Particularly in battery-powered systems where input voltage may approach the output requirement.
- Sensor Modules : Analog sensors (temperature, pressure, light) that require clean, ripple-free supply rails to maintain measurement accuracy.
- Low-Power RF and Communication ICs : Such as Bluetooth Low Energy (BLE) modules, Wi-Fi chips in sleep/standby modes, and GPS receivers, where noise on the supply can degrade signal integrity.
- Portable and Handheld Devices : Including medical monitors, digital calipers, and handheld scanners, where extended battery life is critical.
- Always-On Circuits : Real-time clocks (RTCs), memory backup power, and system monitoring circuits that draw continuous, low current.
### Industry Applications
- Consumer Electronics : Smartphones, tablets, digital cameras, and wearables for post-regulation and noise-sensitive sub-circuits.
- Industrial Automation : PLC I/O modules, sensor interfaces, and HMI panels where reliability and stability are paramount.
- Automotive Infotainment & Body Electronics : Non-critical, low-power subsystems like LED lighting control, memory backup, or peripheral controllers, noting it is not AEC-Q100 qualified.
- Medical Devices : Portable diagnostic equipment, wearable monitors, and bedside devices benefiting from its low quiescent current and thermal performance.
- IoT End Nodes : Battery-operated sensors and edge devices in smart agriculture, building automation, and asset tracking.
### Practical Advantages and Limitations
Advantages:
- Ultra-Low Dropout Voltage : Typically 85 mV at 150 mA load (Tj = 25°C), enabling operation with input voltages as low as ~5.085 V to maintain a regulated 5.0 V output. This maximizes efficiency and battery life.
- Low Quiescent Current : 85 µA typical (IQ), reducing power loss in standby modes.
- Excellent Load/Line Transient Response : Designed for stability with low-ESR ceramic capacitors (≥ 1.0 µF), simplifying the bill of materials (BOM).
- Integrated Protection Features : Includes current limit, thermal shutdown, and reverse-battery protection.
- Low Output Noise : Bypassable internal reference allows for even lower noise performance with an external capacitor (CBYP pin).
Limitations:
- Fixed Output Voltage : The LP2986IMM50NOPB provides a fixed 5.0 V output. Variable output versions (e.g., LP2986-ADJ) are needed for other voltages.
- Moderate Current Capacity : 150 mA maximum output current is insufficient for powering high-current loads like motors or high-performance processors.
- Thermal Dissipation : In a small MSOP-8 package, maximum power dissipation is limited by junction temperature. At full load (150 mA) with a high input-output differential, a thermal pad or heatsink may be required.
- Not Automotive Grade : This specific part is not AEC-Q100 qualified for full automotive applications.
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## 2. Design Considerations
### Common Design Pitfalls and Solutions
1. Pit
