UCC3809D-2 TI SOIC-8 Power ICs

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 an under-voltage lockout featuring a startup current of 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.

The oscillator frequency and maximum duty cycle are programmed with two resistors and a capacitor. The UCC3809 family also features a 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.

• User Programmable Soft Start With Active Low Shutdown.
• User Programmable Maximum Duty Cycle.
• Accessible 5V Reference.
• Undervoltage Lockout.
• The operation to 1MHz.
• 0.4A Source/0.8A Sink FET Driver.
• Low 100μ A Startup Current.