LT3502IDC#TRPBF

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LT3502IDC#TRPBF Application Field and Working Principle

Introduction

The LT3502IDC#TRPBF is a Dispersive Power Modes (DPM) type DC-DC switching regulator that employs a high-bandwidth current-mode loop, with very fast response time, for immediate transient recovery and stable loop frequency. The device is perfect for low output voltage and current applications like applications such as voltage regulator and seed generator. The power source has an ultra-high efficiency, so it is achievable to convert input power efficiently into output power. The wide input range makes LT3502IDC#TRPBF adaptable to unregulated supplies and batteries. With its integrated high-side and low-side switches, this device can be used for step-down and inverting modes.

Application Field

• LT3502IDC#TRPBF is suitable for applications with low output voltage and current, such as voltage regulators, seed generators, and so on.
• It can be used as a wide input voltage range step down and inverting regulator, which makes it suitable for systems with unregulated sources.
• It can also be used as a current-mode converter thanks to its high-bandwidth switching current-mode loop.

Working Principle

The LT3502IDC#TRPBF integrated switching function employs either of two options: the current-mode or a voltage-mode operation. When the current-mode is employed, the current loop control is used to regulate the output voltage in the DC-DC converter.In the current-mode, the inductor current is sensed by the internal high-bandwidth current-mode loop and so is the output voltage. The inductor current is then compared with a reference voltage and the difference, or error signal, is compared with the high-frequency oscillator to generate the switching signal. Consequently, a high-frequency non-overlapping switch drive output is produced, enabling fast transient response as well as stable frequency operation.The voltage-mode operation, on the other hand, monitors the output voltage of the DC-DC converter rail. When the voltage-mode is employed, the error signal is generated by comparing the output rail voltage with an internal reference. The error signal is then compared with the oscillator to generate the switch drive signal. The feedback-driven current mode has a wide-range compensation, a full-flower frequency compensation and robust supply transients and noise immunity, making the device capable of achieving high-speed performance with very short time response capabilities. The device is supplied in a 3mm2, 8-lead plastic DFN package and offers an integrated, 1µA shutdown current and an advanced power save mode that allows the device to operate at an efficiency of over 95%.

Conclusion

The LT3502IDC#TRPBF DC-DC switching regulator is a high-bandwidth current-mode controller, suitable for step down and inverting applications with unregulated sources. The device offers an advanced power save mode with integrated high-side and low-side switches, optimum output voltage range and adjustable switching frequency, among other features.