LM644A2-Q1中文资料具有顶部外露焊盘的汽车级 36V、12A、低 Iq 双路输出同步降压转换器数据手册TI规格书

描述 Description

The LM644A2-Q1 is a 36V, synchronous, buck, DC/DC converter for high-current single or dual outputs. The device uses an interleaved, stackable, current-mode control architecture for easy loop compensation, fast transient response, excellent load and line regulation, and accurate current sharing with an output clock supporting up to 6 phases for currents up to 36A. A high-side switch minimum on-time of 50ns gives large step-down ratios, enabling the direct conversion from 12V, 24V, or automotive inputs to low-voltage rails for reduced system complexity and design cost.

The LM644A2-Q1 incorporates spread spectrum in an optimized enhanced HotRod QFN package, with wettable flanks, and low inductance input bypass configuration to minimize EMI. Dual Random Spread Spectrum (DRSS) frequency hopping is set to ±10% (typical), drastically reducing emissions through a combination of triangular and pseudo-random modulation. A bias pin allows the LM644A2-Q1 to save losses by powering the device from the output of the converter, achieving a 9µA no-load quiescent current to extend the operating run-time in battery-powered systems. The LM644A2-Q1 can maintain high efficiency light-load operation even when stacking multiple devices for high efficiency over the full load range.

特性 Features

AEC-Q100 qualified for automotive applications:

Device temperature grade 1: –40°C to +125°C ambient operating temperature

Operation up to 150°C junction temperature

Thermally enhanced package provides exposed top and bottom thermal pads and enables dual-side cooling



Functional Safety-Capable

Documentation available to aid functional safety system design



Designed for Low EMI

Symmetrical input voltage pins with > 1mm clearance to ground

Pin selectable spread spectrum option

Pin selectable FPWM or auto mode operation

Enhanced HotRod™ QFN (25) package with wettable flanks

Switching frequency from 100kHz to 2.2MHz

Meets CISPR 25 class 5 EMI requirements



Single and dual-output features

Wide input voltage range of 3V to 36V

1% accurate fixed 3.3V, 5V or adjustable outputs from 0.8V to 20V

Hiccup-mode overcurrent protection and thermal shutdown protection with hysteresis

Precision ENABLE and PGOOD functions

50ns tON(min) for high VIN / VOUT ratio

80ns tOFF(min) for low dropout



Versatile dual-output operation

Shutdown mode current: 0.5µA typical

No-load standby current: 9µA typical

Built-in compensation and 3ms soft start

Independent precision ENABLE and PGOOD



Adaptable single-output operation

> 95% efficient for an 8A load, single output, VIN =12V, VOUT = 5V

External compensation and adjustable soft start

PGOOD, SYNCIN, and SYNCOUT functions



Pin-to-pin Compatible with LMQ644A2-Q1