UCC2808-1

Low Power Current Mode Push-Pull PWM UCC1808-1/-2 UCC2808-1/-2 UCC3808-1/-2 PRELIMINARY FEATURES 130µA Typical Starting Current 1mA Typical Run Current Operation to 1MHz Internal Soft Start On Chip Error Amplifier With 2MHz Gain Bandwidth Product On Chip VDD Clamping Dual Output Drive Stages In Push-Pull Configuration Output Drive Stages Capable Of 500mA Peak Source Current, 1A Peak Sink Current BLOCK DIAGRAM DESCRIPTION The UCC3808 is a family of BiCMOS push-pull, high-speed, low power, pulse width modulators. The UCC3808 contains all of the control and drive circuitry required for off-line or DC-to-DC fixed frequency current-mode switching power supplies with minimal external parts count. The UCC3808 dual output drive stages are arranged in a push-pull configuration. Both outputs switch at half the oscillator frequency using a toggle flip-flop. The dead time between the two outputs is typically 60ns to 200ns depending on the values of the timing capacitor and resistors, thus limits each output stage duty cycle to less than 50%. The UCC3808 family offers a variety of package options temperature range options, and choice of undervoltage lockout levels. The family has UVLO thresholds and hysteresis options for off-line and battery powered systems. Thresholds are shown in the table below. Part Number UCCx808-1 UCCx808-2 Turn on Threshold 12.5V 4.3V Turn off Threshold 8.3V 4.1V 9/97 UDG-97008 ABSOLUTE MAXIMUM RATINGS Supply Voltage (IDD ≤ 10mA) . . . ....