IWST-TR from iWatt, Inc.. Find the PDF Datasheet, Specifications and Distributor Information. IW Datasheet, IW PDF, Low Power Off Line Digital PWM Controller. IW datasheet,Page:6, iW Low-Power Off-line Digital PWM Controller Pin Detail Pin 1 – VSENSE Sense signal input from auxiliary winding.
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The controller will shut off with 6 consecutive pulses after start-up. The controller will shut off with. Home – IC Supply – Link.
The rectifying diode D1 is reverse biased and the load datashwet I O is supplied by the secondary capacitor C O. The current in Q 1 ramps up linearly at a rate of: If the output voltage rises above the minimum threshold before soft-start is completed, the device assumes that the output load is very light and immediately changes to PFM operation.
CCM protection there are some trade-offs between size. As the output load. The voltage across L M is datasheft g tassuming the voltage dropped across Q 1 is zero.
This pin also provides the supply current to the IC during start-up. The iW uses the primary feedback only with no secondary feedback loop.
Wi1688 pin also provides the supply. Home – IC Supply – Link. It also provides input undervoltage and overvoltage protection. In order to regulate the output voltage within a tight. Once the V IN pin voltage has reached its turn-on threshold, the iW starts switching, but limits the on-time to a percentage of the maximum on- time. Sense signal input representing the average line voltage.
Daasheet, the IC will remain biased which will discharge the. If the output voltage. Conduction Mode CCMwhich could saturate the. When Q1 turns off, D1 conducts and the stored energy E g t is delivered to the output. Due to some limitations of constant current mode. V IN is used for line regulation.
The energy E g t is stored in the magnetizing inductance L M. P r There are datazheet conditions for output short-circuit detection: The nominal switching frequency is 40 kHz.
The controller will continue to attempt to soft-start until the error condition is removed. The iW incorporates an internal soft-start function.
If the system tries to go into CCM mode, the iW will send ns minimum on-time with a ns delay. There are two conditions for output short-circuit detection:. Power supply for the controller during normal operation. Pin 2 — GND Analog signal and power ground. The controller will continue to attempt to soft-start until.
If the output voltage rises above the minimum threshold. Pin 4 — V CC Power supply for the controller during normal operation. The loop stability is guaranteed by design to provide at least 45 degrees of phase margin and —20dB of gain margin. A short circuit condition is interpreted as any time the output.
The daasheet includes functions that protect against input. Thereafter, the on-time will be modulated by the line voltage and the off-time is modulated by the load current. The soft-start time is set at 5 ms.
The iW has a built-in protection circuit which detects if. If no voltage is detected on V SENSE after 20 output pulses during start-up, it is assumed that the auxiliary winding of the transformer is either open or shorted, and the iW shuts down. The iW has been designed to work in constant-current. The input line voltage is scaled using a wi1688 network.
It also provides input undervoltage.
This condition could occur when the output is shorted, kw1688 when there is a fault in the auxiliary winding. The iW will attempt to restart from any of these fault.
If the voltage at these pins exceed their undervoltage or overvoltage thresholds for more than cycles, the iW will stop switching.