Devices like the AMC7135 350 mA advanced current regulator provide a simple and reliable solution for driving high-brightness LEDs, especially in portable lighting systems such as flashlights, headlamps, and battery-powered lamps. This article will discuss the AMC7135 overview, pinout details, functional block diagram, specifications, key features, circuit operation, etc.

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AMC7135 Overview

The AMC7135 350 mA Advanced Current Regulator from ADDtek is a linear constant-current driver designed mainly for powering high-brightness LEDs. Unlike standard voltage regulators, the AMC7135 controls the current flowing through the load, providing a stable 350 mA output current. This helps maintain consistent LED brightness and protects LEDs from overcurrent damage. Because of its compact design and simple operation, the device is widely used in LED flashlights, portable lighting systems, and other small electronic lighting applications.

The regulator is built using a Bi-CMOS process, allowing it to operate with low dropout voltage and low power consumption. It typically supports a 2.7 V to 6 V input voltage range and includes built-in protection features such as short-circuit and thermal protection. These features improve reliability and make the AMC7135 suitable for battery-powered LED circuits and compact lighting designs.

If you are interested in purchasing the AMC7135, feel free to contact us for pricing and availability.

AMC7135 CAD Models

        AMC7135 Symbol                  AMC7135 Footprint                  AMC7135 3D Model

AMC7135 Pinout Details

Alternatives & Equivalent Model

• AMC7136

• AMC7140

• CAT4101

• AL5809

• NSI45030AT1G

AMC7135 Functional Block Diagram

The AMC7135 functional block diagram shows how the device regulates a constant output current for LED driving. The circuit begins at the VDD pin, which supplies power to the internal components. Inside the IC, a band-gap reference circuit generates a stable reference voltage that remains constant even if the supply voltage or temperature changes. This reference signal is important because it serves as the basis for maintaining a steady output current.

The reference voltage is sent to the control circuit, which monitors and regulates the current flowing through the device. The control circuit continuously compares the internal reference with the current flowing to the load. Based on this comparison, it adjusts the internal transistor to keep the current stable.

At the output stage, a power transistor controls the current that flows from OUT to GND through the LED load. By adjusting the conduction of this transistor, the AMC7135 maintains a nearly constant 350 mA current, ensuring stable LED brightness and protecting the LED from overcurrent.

AMC7135 Specifications

AMC7135 Features

350 mA Constant Sink Current

The AMC7135 provides a fixed 350 mA constant sink current, making it suitable for driving high-brightness LEDs. This stable current helps maintain consistent LED brightness and prevents damage caused by current fluctuations.

Output Short / Open Circuit Protection

The device includes built-in short-circuit and open-circuit protection. These protection features help safeguard the IC and the connected LED when abnormal conditions occur in the circuit.

Low Dropout Voltage

The AMC7135 operates with a low dropout voltage, meaning it can maintain the regulated current even when the input voltage is only slightly higher than the LED voltage. This improves efficiency in battery-powered applications.

Low Quiescent Current

The regulator consumes very low internal operating current, which helps reduce power loss and extend battery life in portable lighting devices.

Wide Supply Voltage Range

It supports a supply voltage range from 2.7 V to 6 V, allowing the device to work with common battery configurations such as lithium-ion cells and small DC power sources.

2 kV HBM ESD Protection

The IC includes 2 kV Human Body Model (HBM) ESD protection, which helps protect the device from electrostatic discharge during handling and assembly.

Advanced Bi-CMOS Process

The AMC7135 is manufactured using an advanced Bi-CMOS process, which combines the advantages of bipolar and CMOS technologies to provide stable performance and improved reliability.

Compact Package Options

The device is available in SOT-89 and TO-252 packages, making it suitable for compact PCB layouts and efficient thermal performance in LED driver designs.

AMC7135 Working in Circuit

The AMC7135 working circuit shows how the device is used as a constant current LED driver. The input voltage, typically 2.7 V to 6 V, is applied to the VIN line and connected to the VDD pin of the AMC7135. A capacitor CIN is placed between the input and ground to filter noise and stabilize the power supply. This helps ensure that the regulator receives a clean and stable voltage during operation.

Inside the circuit, the AMC7135 controls the current flowing through the OUT pin. The LED is connected between the input supply and the OUT pin, allowing the regulator to act as a current sink. The device automatically adjusts the internal transistor so that the LED current remains close to 350 mA, providing stable brightness and protecting the LED from excessive current.

An output capacitor CO is connected between the output node and ground to reduce noise and improve circuit stability.