COT synchronous step-down regulator from Texas Instruments

The Texas Instruments LM5169 is a synchronous step-down converter designed to adjust over a wide input voltage range, minimizing the need for external surge suppression components. A controlled on-off time of 50 ns (minimum) helps achieve a large step-down conversion ratio that supports direct step-down from 48 V nominal input to the low rail, thereby reducing system complexity and solution cost. This converter maintains operation when input voltage drops to 6 V and has a duty cycle of nearly 100% if needed, making it ideal for industrial and high-count battery pack applications with a wide input power range.

The LM5169 integrates high-voltage and low-voltage mosFets to provide A maximum output current of 0.65 A. Constant-on-time (COT) control architecture provides nearly constant switching frequency with excellent load and line transient response. The converter is available in FPWM or auto mode versions. The FPWM mode provides forced-CCM work throughout the load range and supports isolated Fly-Buck converter applications. The automatic mode enables ultra-low IQ and diode simulation mode operation to achieve high light load efficiency

Features

● Designed for reliability in harsh conditions:
-   Wide input voltage range: 6 V to 120 V
-   Junction temperature range: -40°C to +150°C
-   Fixed internal Soft Start timer: 3 ms
-   Peak and valley current limiting protection
-   Input UVLO and heat off protection

● Ideal for expandable industrial power supplies and battery packs
-   Minimum on/off time: 50 ns
-   Adjustable switching frequency: up to 1 MHz
-   Diode simulation, with high light load efficiency
-   With low static current (< 10 µA) automatic mode
-   FPWM for Fly-Buck converter function
-   Shutdown static current: 3μA
-   Compatible with pins of LM5164, LM5163, LM5017, and LM34927

● Integration reduces the size and cost of the solution
-   COT mode control architecture
-   Integrated NFET step-down switch: 1.9Ω
-   Integrated NFET Synchronous rectifier: 0.71Ω
-   Internal voltage reference: 1.2V
-   There is no loop compensation element
-   Internal VCC bias regulator and bootstrap diode
-   Good indicator for leaky power supply
-   SOIC PowerPAD™ integrated circuit package

Applications

● Communication: Brick power module
● Industrial battery pack (≥10S)
● Battery packs for electric bicycles, electric scooters and LeVs