LD39015M33R - 150mA, 3.3V Ultra-Low Noise LDO | STMicroelectronics
MPN: LD39015M33R β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.45 | $0.45 |
| 10 | $0.38 | $3.80 |
| 100 | $0.3 | $30.00 |
| 500 | $0.25 | $125.00 |
| 1,000 | $0.2 | $200.00 |
Drop-in alternatives for LD39015M33R β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
LD39015M28R
β Drop-Inπ Reference alternative (not in catalog)
LD39015M18R
β Drop-Inπ Reference alternative (not in catalog)
TLV70033
β Drop-Inπ Reference alternative (not in catalog)
AP2127K-3.3
β Drop-Inπ Reference alternative (not in catalog)
MIC5205-3.3YM5
β Drop-Inπ Reference alternative (not in catalog)
LD39015M33R Maximum Ratings & Electrical Characteristics
| Output Type | Fixed |
| Output Voltage | 3.3 V |
| Maximum Output Current | 150 mA |
| Input Voltage Range | 1.5 V to 5.5 V |
| Dropout Voltage | 100 mV at 150 mA |
| Output Noise | 30 uVrms (10 Hz to 100 kHz) |
| PSRR | 60 dB at 1 kHz |
| Quiescent Current | 40 uA |
| Output Voltage Accuracy | Β±2% |
| Operating Temperature | -40Β°C to +125Β°C |
| Package | SOT-23-5 |
| Mounting Type | Surface Mount |
| Enable Pin | Yes (active-high) |
| Thermal Shutdown | Yes |
| Current Limit | Yes |
| RoHS Status | Compliant |
LD39015M33R Pin Configuration
| Pin 1 | IN β Input voltage supply |
| Pin 2 | GND β Ground |
| Pin 3 | EN β Enable (active high) |
| Pin 4 | NC β No connect |
| Pin 5 | OUT β Regulated output voltage |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
LD39015M33R is suitable for 6 applications: Battery-Powered IoT Devices, Portable Audio Players, Wireless Modules (BLE/Zigbee), MEMS Sensor Power, Industrial Control Systems, Medical Monitoring Devices.
Battery-Powered IoT Devices
The LD39015M33R is ideal for battery-powered IoT devices such as wireless sensors and beacons. Its low quiescent current of 40uA extends battery life, while the 3.3V output is compatible with common microcontrollers and wireless modules. The low dropout voltage of 100mV allows operation down to 3.4V input, maximizing usable battery capacity. In a typical IoT node, the LDO is placed between the battery (e.g., a CR2032 coin cell) and the system load, with a 1uF ceramic capacitor on the input and output. The enable pin can be used to power down the regulator in sleep mode, further reducing power consumption. Compared to a switching regulator, the LDO offers simplicity and low noise, which is critical for RF modules that are sensitive to supply ripple.
Recommended
Portable Audio Players
The LD39015M33R provides a clean 3.3V supply for audio codecs and amplifiers in portable audio players. Its ultra-low output noise of 30uVrms and PSRR of 60dB at 1kHz ensure that supply noise does not degrade the audio signal-to-noise ratio. In a typical audio player, the LDO is used to power the DAC and headphone amplifier, with the input connected to the battery or a 5V boost converter. A 1uF ceramic output capacitor is sufficient for stability. The low quiescent current helps extend playback time. While a switching regulator could be more efficient, the LDO's low noise is essential for high-fidelity audio, making the LD39015M33R a preferred choice for noise-sensitive audio paths.
Recommended
Wireless Modules (BLE/Zigbee)
The LD39015M33R is well-suited for powering Bluetooth Low Energy (BLE) and Zigbee modules, which require a stable 3.3V supply with low noise to maintain RF performance. The LDO's high PSRR of 60dB at 1kHz attenuates ripple from the battery or DC-DC converter, preventing interference with the RF transceiver. In a typical module design, the LDO is placed between the main supply rail and the module's VCC pin, with decoupling capacitors on both input and output. The enable pin allows the host MCU to power down the module in sleep mode, reducing overall system power consumption. The low dropout voltage ensures the module operates even when the battery voltage drops close to 3.4V.
Recommended
MEMS Sensor Power
The LD39015M33R provides a clean, stable 3.3V supply for MEMS sensors such as accelerometers, gyroscopes, and pressure sensors. These sensors often have analog outputs that are sensitive to supply noise, which can affect measurement accuracy. The LDO's low output noise of 30uVrms and high PSRR ensure a quiet supply, improving sensor performance. In a typical sensor module, the LDO is powered from a battery or a 5V rail, with a 1uF ceramic capacitor on the output. The small SOT-23-5 package is ideal for compact sensor nodes. The enable pin can be used to power down the sensor in low-power modes, reducing overall system current draw.
Recommended
Industrial Control Systems
The LD39015M33R is suitable for industrial control systems that require a reliable 3.3V supply for microcontrollers, sensors, and communication interfaces. Its wide operating temperature range of -40Β°C to +125Β°C ensures reliable operation in harsh industrial environments. The LDO's internal current limiting and thermal shutdown protect the system from overcurrent and overtemperature faults. In a typical industrial application, the LDO is powered from a 24V bus via a buck converter, providing a clean 3.3V rail for logic circuits. The low dropout voltage and low quiescent current are beneficial for always-on monitoring circuits. The SOT-23-5 package is easy to integrate into existing PCB designs.
Recommended
Medical Monitoring Devices
The LD39015M33R is used in medical monitoring devices such as wearable health trackers and portable patient monitors, where a stable and low-noise 3.3V supply is critical for accurate sensor readings. The LDO's ultra-low noise of 30uVrms prevents interference with sensitive analog front-ends, such as ECG and PPG sensors. In a typical wearable device, the LDO is powered from a lithium-ion battery, with a 1uF ceramic output capacitor. The low quiescent current of 40uA extends battery life, which is essential for continuous monitoring. The enable pin allows the device to enter a low-power sleep mode when not actively measuring. The compact SOT-23-5 package fits well in space-constrained wearable designs.
Recommended
Recommended Products Summary
Engineering reference data for LD39015M33R β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LD39015M28R | TLV70033 | AP2127K-3.3 | MIC5205-3.3YM5 |
|---|---|---|---|---|---|
| Package | SOT-23-5 | SOT-23-5 - same | SOT-23-5 - same | SOT-23-5 - same | SOT-23-5 - same |
| Brand | STMicroelectronics | STMicroelectronics | Texas Instruments | Diodes Incorporated | Microchip Technology |
| Output Voltage | 3.3V | 2.8V | 3.3V | 3.3V | 3.3V |
| Maximum Output Current | 150mA | 150mA | 200mA | 300mA | 150mA |
| Dropout Voltage | 100mV at 150mA | 100mV at 150mA | 200mV at 200mA | 300mV at 300mA | 165mV at 150mA |
| Output Noise | 30uVrms | 30uVrms | 40uVrms | 50uVrms | 26uVrms |
| PSRR at 1kHz | 60dB | 60dB | 65dB | 55dB | 70dB |
| Quiescent Current | 40uA | 40uA | 31uA | 50uA | 80uA |
Key Differentiators
- Ultra-low output noise of 30uVrms (vs TLV70033)
- Low quiescent current of 40uA (vs MIC5205-3.3YM5)
- Low dropout voltage of 100mV (vs AP2127K-3.3)
Design Notes
Place a 1uF ceramic capacitor on the input and output as close to the pins as possible. The LD39015M33R is stable with ceramic output capacitors as low as 1uF. For optimal transient response, a 2.2uF output capacitor is recommended. Ensure the ground pin is connected to a solid ground plane to minimize noise.
The SOT-23-5 package has a thermal resistance (theta_JA) of approximately 250Β°C/W. At maximum output current of 150mA and a typical dropout of 100mV, power dissipation is only 15mW, resulting in a negligible temperature rise. However, in high ambient temperature environments, ensure that the junction temperature does not exceed 125Β°C. For higher power dissipation, consider using a larger copper area on the PCB to improve heat dissipation.
Do not exceed the input voltage range of 5.5V. The enable pin has an internal pull-down, so if left floating, the regulator will be disabled. Ensure the EN pin is driven high (above 0.9V) to enable the output. Avoid using the NC pin for routing; it is not connected internally and should be left unconnected or tied to ground.
Compliance Information
RoHS compliant per STMicroelectronics product page. Not AEC-Q100 qualified. Halogen-free status not specified in available data.
