MC44605屬于集成電路（IC）的ACDC轉(zhuǎn)換器離線開關(guān)。由安森美半導(dǎo)體公司制造生產(chǎn)的MC44605AC DC 轉(zhuǎn)換器，離線開關(guān)該系列是元器件級(jí)控制產(chǎn)品，用于構(gòu)建將交流市電轉(zhuǎn)換為直流電（通常電壓大幅降低）的設(shè)備。集成和未集成系統(tǒng)主要開關(guān)元件的器件均包括在內(nèi)。由于高輸入輸出電壓比，以及此類系統(tǒng)中通常需要隔離，這些器件通常與外部變壓器配合使用。盡管通常使用定制變壓器來實(shí)現(xiàn)此用途，但也有許多專門用于此用途的庫(kù)存產(chǎn)品，請(qǐng)參見“開關(guān)轉(zhuǎn)換器，SMPS 變壓器”標(biāo)題。

The MC44605 is a high performance current mode controller that is specifically designed for off?line converters. This circuit has several distinguishing features that make it particularly suitable for multisynchronized monitor applications.

The MC44605 synchronization arrangement enables operation from 16 kHz up to 130 kHz. This product was optimized to operate with universal mains voltage, i.e., from 80 V to 280 V, and its high current totem pole output makes it ideally suited for driving a power MOSFET.

The MC44605 protections enable a well?controlled and safe power management. Four major faults while detected, activate the analogic counter of a disabling block designed to perform a latched circuit output inhibition.

特性 Features

? Pb?Free Package is Available*

Current Mode Controller

? Current Mode Operation up to 250 kHz Output Switching Frequency

? Inherent Feed Forward Compensation

? Latching PWM for Cycle?by?Cycle Current Limiting

? Oscillator with Precise Frequency Control

? Externally Programmable Reference Current

? Secondary or Primary Sensing (Availability of Error Amplifier Output)

? Synchronization Facility

? High Current Totem Pole Output

? Vcc Undervoltage Lockout with Hysteresis

? Low Output dV/dT for Low EMI Radiations

? Low Startup and Operating Current

Safety/Protection Features

? Soft?Start Feature

? Demagnetization (Zero Current Detection) Protection

? Overvoltage Protection Facility against Open Loop

? EHT Overvoltage Protection (E.H.T.OVP): Detection of too High Synchronization Pulses

? Winding Short Circuit Detection (W.S.C.D.)

? Limitation of the Maximum Input Power (M.P.L.): Calculation of Input Power for Overload Protection

? Overheating Detection (O.H.D.): to Prevent the Power Switch from an Excessive Heating

Latched Disabling Mode

? When one of the following faults is detected: EHT overvoltage,

Winding Short Circuit (WSCD), a too high input power (M.P.L.),

power switch overheating (O.H.D.), an analogic counter is activated

? If the counter is activated for a time that is long enough, the circuit

gets definitively disabled. The latch can only be reset by making

decrease the Vcc down to about 3.0 V, i.e., practically by unplugging

or turning off the SMPS.