TPS54429PWP

TPS54429PWP Application Field and Working PrincipleThe TPS54429PWP is a high-performance dual-input synchronous buck DC-DC converter from Texas Instruments’ paralleled Buck family. It enables power save operation from both high-voltage bus rails and low-voltage bus rails and is designed to provide up to 26A continuous current over a wide output voltage range with tight regulation (<1.5% output accuracy typical) at a differential input voltage range of 4.5V to 36V.

This dual-input synchronous buck DC-DC converter is released in a compact 3mm × 3mm 16-pin low-profile VQFN package size, reducing total board area and costs. The TPS54429PWP includes cycle-by-cycle current-limit, hiccup-mode over-current protection, thermal-shutdown, and always-on, low current standby modes. It provides a single external resistor to set the output voltage from 0.5V to 5V, and that voltage is adjustable with an external feedback voltage of 1.2V with an accuracy of about 10 mV. In this case the device automatically compensates for input voltage variations, external line and load transients, and process variations.

Application Fields

The TPS54429PWP is ideal for point-of-load and intermediate bus applications such as telecom, networking, and industrial as well as in data communication, handheld and battery-powered applications. This device architecture is particularly well-suited for use with large FPGAs, processors, and memory systems.

Because of its wide input range and internal synchronous rectification control, the TPS54429PWP offers multiple benefits such as very low ripple noise, efficient high current delivery and wide load range capability. Additionally, it also provides an active current balance between two outputs of the dual synchronous buck converter, a condition that increases overall power efficiency and reduces unwanted heating in the system.

Working Principle

The internal circuit block diagram of the TPS54429PWP is shown in Fig 1. The device employs a dual synchronous buck converter with internally fixed 540 kHz frequency. The switching frequency may be synchronized to an external frequency from 300 kHz to 1.2 MHz when Synchronization input is applied. An on-chip voltage regulator provides a 5V reference voltage for the internal circuitry. It minimizes the amount of additional components that need to be connected externally.

When the EN/UV (chip enable) input is high, the device starts switching and the output voltage is greater than 90% of the programmed output voltage. When the input voltage is below the undervoltage threshold, the switching stops and the output voltage drops below 1V in a very short time.

The chip includes two voltage reference blocks, one for each channel. This feature allows to get a low-tolerance and low temperature drift output voltage that is independently adjustable from 0.5V to 5V. The TPS54429PWP maximizes efficiency by using synchronous rectification in both positive and negative cycles. It also incorporates advanced control techniques such as cycle-by-cycle peak current limit, short-circuit protection, and thermal shutdown.

Conclusion

The TPS54429PWP is a high-performance, highly efficient dual-input synchronous buck DC-DC converter. It offers a 3mm×3mm package size, low voltage drop-out, wide input voltage range and always-on, low current standby modes for modern applications. This device architecture is particularly suitable for use with large FPGAs, processors, and memory systems. The TPS54429PWP is ideal for telecom, networking and industrial applications, handheld and battery-powered applications.