HT7333 3.3V LDO Voltage Regulator Datasheet Guide

FREE-SKY (HK) ELECTRONICS CO.,LIMITED / 03-04 15:55

This article will discuss the HT7333 overview, pin configuration, functional block diagram, specifications, features, application circuit, alternatives, comparison with other regulators, applications, and manufacturer details.

Catalog

1. HT7333 Voltage Regulator Overview

2. HT7333 Voltage Regulator CAD Models

3. HT7333 Voltage Regulator Pinout Details

4. Alternatives & Equivalent Model

5. HT7333 Functional Block Diagram

6. HT7333 Voltage Regulator Specifications

7. HT7333 Voltage Regulator Features

8. HT7333 Application Circuit

9. HT7333 Voltage Regulator Applications

10. Comparison: HT7333 vs Other Voltage Regulators

11. Mechanical Dimensions

12. Manufacturer

HT7333 Voltage Regulator Overview

The HT7333 is a fixed 3.3V low-dropout (LDO) linear voltage regulator designed for low-power electronic applications. Built using CMOS technology, it offers an extremely low quiescent current of about 4µA, making it ideal for battery-operated and portable devices. It supports input voltages up to 12V while maintaining a stable 3.3V output with minimal dropout voltage.

Internally, the HT7333 integrates a precision voltage reference, an error amplifier, and a current-limited output stage. These features ensure accurate voltage regulation and reliable protection against overload conditions. The device is available in compact packages such as TO-92 and SOT-89, allowing easy integration into space-constrained designs.

If you are interested in purchasing the HT7333, feel free to contact us for pricing and availability.

HT7333 Voltage Regulator CAD Models

HT7333 Voltage Regulator Pinout Details

HT7333 TO-92 Package

Pin Number	Pin Name	Description
1	GND	Ground connection
2	VIN	Input voltage (Up to 12V max)
3	VOUT	Regulated 3.3V output

HT7333 SOT-89 Package

Pin Number	Pin Name	Description
1	GND	Ground connection
2	VIN	Input voltage
3	VOUT	Regulated 3.3V output
Tab	VOUT	Connected internally to output (improves heat dissipation)

Alternatives & Equivalent Model

• LM1117-3.3

• LM1117-ADJ

• LM723

• LM317

• AMS1117-3.3

• LD1117-3.3

• MIC5205-3.3

• MCP1700-3302

• LP2985-33

• XC6206P332MR

HT7333 Functional Block Diagram

How the regulator maintains a stable 3.3V output from a higher input voltage? The input voltage (VIN) passes through an internal pass transistor that controls how much current flows to the output (VOUT). This transistor acts like a variable resistor, adjusting automatically to keep the output voltage constant.

Inside the device, a precision voltage reference (Vref) provides a stable internal reference signal. An error amplifier compares a portion of the output voltage (fed back through internal resistors) with this reference voltage. If the output rises or drops, the error amplifier adjusts the pass transistor accordingly, increasing or decreasing current flow to correct the voltage.

The diagram also shows internal current limiting, which protects the regulator from overload or short-circuit conditions. The circuit works as a closed-loop control system to ensure accurate, stable, and safe 3.3V regulation.

HT7333 Voltage Regulator Specifications

Absolute Maximum Ratings

Parameter	Rating	Unit
Supply Voltage (VSS)	VSS −0.3 to VSS +14	V
Power Consumption (*1.applied to TO-92)	500	mW
Power Consumption (*2.applied to SOT-89)	500	mW
Storage Temperature	−50 to +125	°C
Operating Temperature	−40 to +85	°C

Electrical Characteristics

Symbol	Parameter	Test Conditions	Min	Typ	Max	Unit
V_OUT	Output Voltage	VIN=4.3V, IOUT=40mA	3.201	3.3	3.399	V
I_OUT(MAX)	Maximum Output Current	VIN=4.3V, VOUT≥2.97V	250	—	—	mA
ΔV_OUT	Load Regulation	VIN=4.3V, 1mA≤IOUT≤80mA	—	45	90	mV
V_DROP	Dropout Voltage	IOUT=40mA	—	90	—	mV
I_SS	Quiescent Current	VIN=4.3V, No load	—	4	8	µA
ΔV_OUT / (ΔVI_N × V_OUT)	Line Regulation	IOUT=40mA, 4.3V≤VIN≤12V	—	0.2	0.3	%/V
V_IN	Input Voltage	—	—	—	12	V
ΔV_OUT / Δ_Ta	Temperature Coefficient	VIN=4.3V, IOUT=40mA, −40°C<Ta<85°C	—	±0.7	—	mV/°C

HT7333 Voltage Regulator Features

• Fixed 3.3V Output – Provides a stable and accurate 3.3V regulated output for digital circuits.

• Ultra-Low Quiescent Current (4µA typ.) – Minimizes power consumption, ideal for battery-powered devices.

• Maximum Output Current up to 250mA – Capable of driving moderate loads such as microcontrollers and modules.

• Low Dropout Voltage (90mV typ. @ 40mA) – Maintains regulation even when input voltage is close to 3.3V.

• High Input Voltage (Up to 12V) – Accepts a wide input range for flexible power design.

• ±3% Output Voltage Accuracy – Ensures reliable and precise voltage regulation.

• Low Temperature Coefficient – Keeps output voltage stable across temperature changes.

• Built-in Current Limiting Protection – Protects the device from overload and short-circuit conditions.

• Compact Package Options (TO-92, SOT-89) – Suitable for both through-hole and surface-mount applications.

HT7333 Application Circuit

The HT7333 application circuit shows a simple and stable way to use the regulator to generate a fixed 3.3V output. The input voltage (VIN) is connected to the regulator’s VIN pin, while the GND pin is tied to a common ground. The regulated 3.3V output is taken from the VOUT pin.

A 10µF capacitor (C1) is placed between VIN and ground to filter input noise and stabilize the supply voltage. Another 10µF capacitor (C2) is connected between VOUT and ground to improve output stability and reduce voltage ripple. These capacitors help maintain smooth operation, especially when the load current changes suddenly.

The diagram also highlights a single-point ground connection, which minimizes noise and ground loop issues. Overall, this circuit demonstrates a basic and reliable configuration for powering 3.3V devices using the HT7333.

HT7333 Voltage Regulator Applications

• Microcontroller power supply (3.3V systems)

• IoT devices

• Battery-powered equipment

• Portable consumer electronics

• Wireless modules (Wi-Fi, Bluetooth)

• Sensors and sensor modules

• Embedded systems

• Data loggers

• Remote controls

• Medical handheld devices

• Smart meters

• Industrial control circuits

Comparison: HT7333 vs Other Voltage Regulators

Feature	HT7333	LM1117-3.3	AMS1117-3.3	MCP1700-3302	LP2985-33
Output Voltage	3.3V (Fixed)	3.3V (Fixed)	3.3V (Fixed)	3.3V (Fixed)	3.3V (Fixed)
Max Output Current	250mA	800mA	1A	250mA	150mA
Dropout Voltage (Typ.)	90mV @ 40mA	~1.1V	~1.1V	178mV	280mV
Quiescent Current (Typ.)	4µA	5mA	5mA	1.6µA	65µA
Max Input Voltage	12V	15V	15V	6V	16V
Voltage Accuracy	±3%	±1%	±1%	±0.4%	±1%
Package Options	TO-92, SOT-89	SOT-223, TO-220	SOT-223	TO-92, SOT-23	SOT-23, SOIC
Best For	Ultra-low power designs	Higher current loads	Higher current loads	Low input voltage systems	Low-noise applications

Mechanical Dimensions

Manufacturer

Holtek, a well-established semiconductor manufacturer, has extensive experience in designing and producing analog and mixed-signal integrated circuits, including low-power voltage regulators like the HT7333. Leveraging mature CMOS process technology, Holtek ensures reliable performance, high yield, and strong quality control across its power management product lines. The company’s manufacturing infrastructure supports both through-hole and surface-mount package options, allowing the HT7333 to be produced efficiently in TO-92 and SOT-89 formats to meet diverse customer needs.