UCC3809DTR-2

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 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.

Key features

• User Programmable Soft Start With Active Low Shutdown
• User Programmable Maximum Duty Cycle
• Accessible 5V Reference
• Undervoltage Lockout