MAX8650 pdf datasheet (电流模式降压型

The MAX8650 synchronous PWM buck controller operates
from a 4.5V to 28V input and generates an
adjustable 0.7V to 5.5V output voltage at loads up to 25A.
The MAX8650 uses a peak current-mode control architecture
with an adjustable (200kHz to 1.2MHz) constant
switching frequency and is externally synchronizable. The
IC’s current limit uses the inductor’s DC resistance to
improve efficiency or an external sense resistor for high
accuracy. The current-limit threshold is adjusted with an
external resistor. Foldback-type current limit can be
implemented to reduce the power dissipation in overload
or short-circuit conditions. Short-circuit protection is
provided based on sensing the current in the low-side
MOSFET. A reference input is provided for use with a
high-accuracy external reference or for double-data-rate
(DDR)-tracking applications.
Monotonic prebiased startup is available for a safe-start
in applications where the output capacitor may have an
initial charge. This feature prevents the output from
pulling low during startup, which is a common characteristic
of conventional buck regulators.
A 180° out-of–phase synchronization output is available
for synchronizing with another converter.

MAX8650同步PWM buck控制器的输入电压范围为4.5V至28V，产生0.7V至5.5V可调输出电压，提供高达25A的输出电流。

MAX8650采用峰值电流控制结构，可调节固定开关频率(200kHz至1.2MHz)，支持外同步。利用电感的直流电阻提供限流功能，有助于提高效率；也可以使用外部检流电阻提高检测精度，通过外部电阻调整过流门限。折返式限流功能降低了过载或短路情况下的功率损耗，通过检测低边MOSFET的电流提供短路保护。提供基准输入，作为高精度外部基准或用于双倍数据速率(DDR)跟踪。

单调预偏置启动功能能够在输出电容已经有初始电荷的情况下保证安全启动。该功能可防止输出在启动时被拉低，这在buck调节器中是一种常见现象。

180°反相同步输出能够实现与其它转换器的同步工作。