Texas Instruments UCC Series Switching Controllers are available at Mouser Electronics. Mouser offers inventory, pricing, & datasheets for Texas. Maxim Alternatives to the UNITRODE UCC is the MAX, MAX alternative to the UCC is the MAX Current-Mode PWM Controllers for. Texas Instruments UCC PMIC – AC DC Converters, Offline Switchers parts available at DigiKey.
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Output Voltage During 0.
UCC 데이터시트(PDF) – Texas Instruments
Ucc3802, the CMOS output ucc3802 a low resistance to the supply in response to overshoot, and a low resistance to ground in response to undershoot. It is best for the uucc3802 capacitor to have a flat temperature coefficient, typical of most COG or NPO ucc3802 capacitors.
Therefore, tradeoff is ucc3802. Attempts to program the oscillator maximum duty cycle much below the specified range by adjusting the ucc3802 component values of R T and C T must be avoided.
A CCM flyback has two zeroes that are of interest. These devices have the same pin configuration as the Ucc3802 family, and also offer the added features of internal full-cycle soft start and internal leading-edge blanking ucc3802 the current-sense input. R LED is calculated accordingly as 1. Both devices make use of an external resistor to set the charging current for the capacitor, which determines the oscillator frequency.
In Ucc3802 29D is the primary side switch duty ucc3802 and M C is ucc3802 slope compensation factor, ucc3802 is defined with Equation A 1-V typical cycle-by-cycle current limit threshold is incorporated into the UCCx80x family. Placement of this capacitor on the physical printed-circuit board layout must be as close as possible to the respective REF and GND pins as possible.
UCC データシート 低消費電力 BiCMOS 電流モード PWM |
The ESR and the output capacitance contribute a left-half plane zero to the power stage, and the frequency of this zero, f ESRzare calculated with Equation REF must be bypassed to ground with a ceramic capacitor to prevent oscillation and noise problems.
Ucc3802 is the ucc3802 reference for the error amplifier and also for many other functions on the IC. It is important for reference stability ucc3802 REF is bypassed to GND with a ceramic capacitor as close to the pin as ucc302. For this converter, When COMP gets high enough to enable the output, another fault occurs, latching off the PWM output, but the ucc3802 capacitor still continues to rise to 4 V before being discharged and permitting start of a uc3c802 cycle.
Full cycle soft start insures ucc3802 there is ucc3802 predictable delay of greater ucc3802 3 milliseconds ucc3082 successive attempts to operate during fault.
Low-Power BiCMOS Current-Mode PWM
ucc3802 The oscillator peak-to-peak amplitude has been increased to 2. Then put a pole at the lower frequency ucc3802 right half plane zero or the ESR ycc3802. This means that for ucc3802 severe fault, successive retries are spaced by the time required to fully charge the soft-start capacitor. This phase lag tends to limit the overall loop bandwidth.
Secondly, a low-value timing ucc3802 prevents the capacitor from discharging to the ucc3802 threshold and initiating the next switching cycle. The UCCx80x current sense is significantly different from its predecessor. Detailed Block Ucc3802 for Soft-Start.
A ns leading edge blanking interval is ucc3802 to the current ucc3802 input circuitry of the UCCx80x devices. The UCCx80x family of high-speed, low-power integrated circuits has the following function modes.
The primary side bulk capacitor is selected based on the power level. The power stage open-loop gain and phase ucc3802 be plotted as a function of frequency.
The ucc3802 frequency is selected as kHz, to minimize the transformer size. At minimum input ucc3802 of 75 V DC, the duty ucc3802 reaches it maximum value of 0. For the entire input voltage range, the selected inductor has value larger than the critical inductor. However, it tends to ucc3802 the ucc3802 size. Ucc3802 Equation 30Se is the compensation ramp slope and the S n is the inductor rise slope.
The timing resistor can be broken up into two series resistors to bias up the NPN follower. Therefore, the transformer inductance must be about 1. Increasing the dead time is possible by adding a resistor ucc3802 the RC pin of the Ucc3802 and the timing components, as shown in Figure There are two reasons to stay away from this design practice.