MAX1846, MAX1847 pdf datasheet

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MAX1846/MAX1847高效率PWM反相控制器能帮助设计者在电信及网络应用中实现小尺寸、低噪声、负电压输出的DC-DC转换器。这两种器件工作于+3V至+16.5V，能产生-500mV至-200V的输出。为了尽可能减小开关噪声，两种器件都采用了电流型、恒定频率的PWM控制方案。工作频率可以通过电阻设置在100kHz至500kHz。

MAX1846采用超小型10引脚µMAX®封装。高工作频率、兼容陶瓷电容和无需变压器的反相拓扑适合于紧凑型设计。最低至100kHz的工作频率兼容电解电容，允许用户采用低成本外部元件。高电流输出驱动器设计用于驱动P沟道MOSFET，可以使转换器的输出高达30W的功率。

MAX1847具有时钟同步和关断的功能。MAX1847还可以配合一个N沟道MOSFET和变压器，构成反相反激式控制器，输出功率可达70W。MAX1847采用16引脚的QSOP封装。

电流模式控制简化了补偿，能提供良好的瞬态响应。通过低侧电流检测实现精确的电流模式控制和过流保护。

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