HT7533-LDO 3.3V Low Dropout Voltage Regulators SOT-89

HT7533-LDO 3.3V Low Dropout Voltage Regulator SOT-89 is an indispensable component for stable power management in battery-powered and low-voltage digital systems. This specific regulator delivers a precise, fixed 3.3V output from a higher input voltage, providing the clean power essential for microcontrollers, sensors, and wireless modules. Because the HT7533 utilizes advanced CMOS technology, it achieves an extremely low quiescent current, which dramatically extends battery life in portable applications. Furthermore, its low dropout voltage (LDO) allows it to maintain regulation even when the input voltage is marginally above the required 3.3V output, maximizing efficiency and utility in space-constrained designs. Consequently, design engineers rely on the SOT-89 package for robust performance in industrial, consumer, and IoT electronics.

Key Features:

• Fixed 3.3V Output: The regulator provides a highly accurate, pre-set 3.3V voltage, which eliminates the need for external adjustment resistors.
• Low Dropout Voltage (LDO): Features an exceptionally low dropout voltage, typically only 300 mV at a 100 mA load, thereby increasing battery utilization.
• Ultra-Low Quiescent Current (I_Q): Consuming a mere 4 μA (typical) of current when idling, this characteristic is crucial for extending the life of portable battery systems.
• High Output Current: The device can source up to 100 mA of output current, sufficient for powering most small-scale embedded systems.
• High Output Voltage Accuracy: Maintains tight regulation with an output voltage tolerance of ±3%.

Technical Specifications:

• Output Voltage (V_OUT): 3.3 V
• Maximum Output Current (I_OUT): 100 mA
• Input Voltage Range (V_IN): 4.0 V to 12.0 V
• Dropout Voltage (V_DO): 300 mV (Typ. at I_OUT = 100 mA)
• Quiescent Current (I_Q): 4.0 μA (Typ.)
• Line Regulation: 0.1% / V (Typ.)
• Operating Temperature Range: −40°C to +85°C

Mechanical Specifications:

• Package Type: SOT-89 (Surface Mount Technology)
• Pin Count: 3 Pins
• Thermal Resistance (Θ_JA): ≈ 120°C/W (Junction-to-Ambient in typical PCB mounting)
• Material: Plastic Encapsulated (Halogen-free option available in some models)

Dimensions:

• Body Length: 4.4 mm
• Body Width: 2.3 mm
• Body Height (Max): 1.5 mm
• Lead Pitch: 1.5 mm and 3.0 mm (Asymmetrical SOT-89 footprint)

Pinout and Wiring:

• Pin 1 (GND): Connect this pin to the circuit ground (0 V). The large center pad is also typically connected to GND for improved heat dissipation.
• Pin 2 (V_OUT): The regulated 3.3 V output voltage source. Connect a high-quality ceramic capacitor (typically 4.7 μF or larger) between V_OUT and GND for stability.
• Pin 3 (V_IN): Connect this pin to the unregulated input voltage source (4.0 V to 12.0 V). Connect a bypass capacitor (typically 1 μF or larger) between V_IN and GND.
• Wiring Note: Importantly, place input and output capacitors as close as possible to the regulator pins to minimize lead inductance and ensure oscillation-free operation.

Datasheet Reference:

• Download Holtek HT75XX-X LDO Regulator Datasheet

Commonly Used in:

• Battery-Powered Devices: Essential for maximizing the operational life of portable electronics due to its low quiescent current.
• IoT and Wireless Nodes: Provides stable power for 3.3V microcontrollers and low-power radio communication modules (e.g., ESP8266, Nordic nRF series).
• Sensor Modules: Used to regulate power for sensitive analog and digital sensors requiring a precise 3.3V supply.

Applications:

• Portable Consumer Electronics: Powering audio players, fitness trackers, and remote controls.
• USB-Powered Peripherals: Generating the 3.3V rail from the 5V USB line with high efficiency.
• System Clock Supplies: Providing a clean, stable voltage source for clock generation circuits.
• Post-Regulation Filtering: Used after a switching supply to provide a quieter power rail for noise-sensitive components.

Equivalent Models:

• S-812C33AMC-C3PT2G (Seiko): A similar 3.3V LDO regulator with comparable low I_Q and SOT-89 package.
• XC6206P332MR (Torex): A highly popular 3.3V LDO in a functional equivalent SOT-23 package, sometimes cross-referenced.
• LM1117-3.3 (Texas Instruments): A more common 3.3V regulator, however, the LM1117 typically has a higher dropout voltage and quiescent current.

Package Includes:

• 1 x HT7533-LDO 3.3V Low Dropout Voltage Regulator SOT-89