Linear Technology LTC3803ES6-5 Constant Frequency Current Mode Step-Down DC/DC Controller

The LTC3803ES6-5 is a high-performance, constant frequency, current mode PWM step-down DC/DC controller packed into a compact SOT-23 package. Manufactured by Linear Technology, now part of Analog Devices, this controller is designed to drive a high-side N-channel MOSFET in a wide range of power supply applications. Its small footprint and high efficiency make it an ideal choice for portable devices and space-constrained applications.

Featuring a fixed operating frequency of 550kHz, the LTC3803ES6-5 allows for the use of small surface mount inductors and capacitors, resulting in a compact and efficient power supply design. The device operates over a wide input voltage range from 4V to 36V, making it versatile for various applications, including industrial, automotive, and telecommunications systems.

The LTC3803ES6-5 integrates vital features such as low startup voltage and a shutdown function that reduces the supply current to just 2μA, enhancing the overall energy efficiency of the system. The device also includes cycle-by-cycle current limit, providing protection against overcurrent conditions, and a soft-start capability that minimizes inrush current during startup.

Its robust design includes undervoltage lockout (UVLO), ensuring that the device operates only when the input voltage is within an acceptable range. This feature prevents the controller from malfunctioning due to insufficient supply voltage. Additionally, the LTC3803ES6-5 boasts a high duty cycle operation, which is crucial for low dropout applications.

Key specifications of the LTC3803ES6-5 include:

• Constant frequency operation at 550kHz
• Wide input voltage range: 4V to 36V
• Low shutdown current: 2μA
• Low minimum startup voltage
• Integrated soft-start function
• Current mode operation for excellent line and load transient response
• Cycle-by-cycle overcurrent protection
• High duty cycle for low dropout operation
• Compact SOT-23 packaging

Overall, the LTC3803ES6-5 from Linear Technology is a reliable and efficient solution for designers looking to implement a compact power supply without compromising on performance or features.