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MAX1846/MAX1847高效率PWM反相控制器能幫助設(shè)計(jì)者在電信及網(wǎng)絡(luò)應(yīng)用中實(shí)現(xiàn)小尺寸、低噪聲、負(fù)電壓輸出的DC-DC轉(zhuǎn)換器。這兩種器件工作于+3V至+16.5V，能產(chǎn)生-500mV至-200V的輸出。為了盡可能減小開(kāi)關(guān)噪聲，兩種器件都采用了電流型、恒定頻率的PWM控制方案。工作頻率可以通過(guò)電阻設(shè)置在100kHz至500kHz。

MAX1846采用超小型10引腳µMAX®封裝。高工作頻率、兼容陶瓷電容和無(wú)需變壓器的反相拓?fù)溥m合于緊湊型設(shè)計(jì)。最低至100kHz的工作頻率兼容電解電容，允許用戶(hù)采用低成本外部元件。高電流輸出驅(qū)動(dòng)器設(shè)計(jì)用于驅(qū)動(dòng)P溝道MOSFET，可以使轉(zhuǎn)換器的輸出高達(dá)30W的功率。

MAX1847具有時(shí)鐘同步和關(guān)斷的功能。MAX1847還可以配合一個(gè)N溝道MOSFET和變壓器，構(gòu)成反相反激式控制器，輸出功率可達(dá)70W。MAX1847采用16引腳的QSOP封裝。

電流模式控制簡(jiǎn)化了補(bǔ)償，能提供良好的瞬態(tài)響應(yīng)。通過(guò)低側(cè)電流檢測(cè)實(shí)現(xiàn)精確的電流模式控制和過(guò)流保護(hù)。

MAX1846/MAX1847 high-efficiency PWM inverting controllers
allow designers to implement compact, lownoise,
negative-output DC-DC converters for telecom
and networking applications. Both devices operate
from +3V to +16.5V input and generate -500mV to
-200V output. To minimize switching noise, both
devices feature a current-mode, constant-frequency
PWM control scheme. The operating frequency can be
set from 100kHz to 500kHz through a resistor.
The MAX1846 is available in an ultra-compact 10-pin
μMAX® package. Operation at high frequency, compatibility
with ceramic capacitors, and inverting topology
without transformers allow for a compact design.
Compatibility with electrolytic capacitors and flexibility
to operate down to 100kHz allow users to minimize the
cost of external components. The high-current output
drivers are designed to drive a P-channel MOSFET and
allow the converter to deliver up to 30W.
The MAX1847 features clock synchronization and shutdown
functions. The MAX1847 can also be configured
to operate as an inverting flyback controller with an Nchannel
MOSFET and a transformer to deliver up to
70W. The MAX1847 is available in a 16-pin QSOP
package.
Current-mode control simplifies compensation and provides
good transient response. Accurate current-mode
control and over current protection are achieved
through low-side current sensing.
Applications