UCC2809PW-1屬于集成電路（IC）的ACDC轉換器離線開關。由美國德州儀器公司制造生產(chǎn)的UCC2809PW-1AC DC 轉換器，離線開關該系列是元器件級控制產(chǎn)品，用于構建將交流市電轉換為直流電（通常電壓大幅降低）的設備。集成和未集成系統(tǒng)主要開關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現(xiàn)此用途，但也有許多專門用于此用途的庫存產(chǎn)品，請參見“開關轉換器，SMPS 變壓器”標題。

FEATURES

? User Programmable Soft Start With

Active Low Shutdown

? User Programmable Maximum Duty

Cycle

? Accessible 5V Reference

? Undervoltage Lockout

? Operation to 1MHz

? 0.4A Source/0.8A Sink FET Driver

? Low 100μA Startup Current

DESCRIPTION

The UCC3809 family of BCDMOS economy low power integrated circuits

contains all the control and drive circuitry required for off-line and isolated

DC-to-DC fixed frequency current mode switching power supplies with

minimal external parts count. Internally implemented circuits include

undervoltage lockout featuring startup current less than 100μA, a user accessible

voltage reference, logic to ensure latched operation, a PWM comparator,

and a totem pole output stage to sink or source peak current. The

output stage, suitable for driving N-Channel MOSFETs, is low in the off

state.

Oscillator frequency and maximum duty cycle are programmed with two

resistors and a capacitor. The UCC3809 family also features full cycle soft

start.

The family has UVLO thresholds and hysteresis levels for off-line and

DC-to-DC systems as shown in the table to the left.

The UCC3809 and the UCC2809 are offered in the 8 pin SOIC (D), PDIP

(N), TSSOP (PW), and MSOP (P) packages. The small TSSOP and

MSOP packages make the device ideal for applications where board

space and height are at a premium.