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控制器的輸入電壓范圍為4.5V至28V，產(chǎn)生0.7V至5.5V可調(diào)輸出電壓，提供高達(dá)25A的輸出電流。

MAX8650采用峰值電流控制結(jié)構(gòu)，可調(diào)節(jié)固定開(kāi)關(guān)頻率(200kHz至1.2MHz)，支持外同步。利用電感的直流電阻提供限流功能，有助于提高效率；也可以使用外部檢流電阻提高檢測(cè)精度，通過(guò)外部電阻調(diào)整過(guò)流門(mén)限。折返式限流功能降低了過(guò)載或短路情況下的功率損耗，通過(guò)檢測(cè)低邊MOSFET的電流提供短路保護(hù)。提供基準(zhǔn)輸入，作為高精度外部基準(zhǔn)或用于雙倍數(shù)據(jù)速率(DDR)跟蹤。

單調(diào)預(yù)偏置啟動(dòng)功能能夠在輸出電容已經(jīng)有初始電荷的情況下保證安全啟動(dòng)。該功能可防止輸出在啟動(dòng)時(shí)被拉低，這在buck調(diào)節(jié)器中是一種常見(jiàn)現(xiàn)象。

180°反相同步輸出能夠?qū)崿F(xiàn)與其它轉(zhuǎn)換器的同步工作。