SCY99080CDWR2G View Datasheet(PDF) - ON Semiconductor

Part Name

Description

View to exact match

SCY99080CDWR2G

High Performance Switch-Mode Power Supply Controller for Backlight and LLC Converters

ON Semiconductor 

Fmax

Outputs

disabled

DDA002C

Frequency

decreases

No

FB fault

variations detection

Operating

Frequency

Fmin

1.2

VFB (V)

Figure 36. VCO Transfer Characteristic

5.1

6

The output frequency remains at Fmin and the duty cycle

is at its maximum value (50% − deadtime) when the FB pin

voltage ranges between 5.1 and 6 V. The frequency of the

converter varies between Fmin and Fmax values if the

feedback voltage changes from 5.1 to 1.2 V. If the feedback

voltage further decreases, the operating frequency stays

constant and is given by the R_fmax resistor value. The IC

disables all drivers once the feedback voltage goes below

1.2 V threshold − skip mode. Please refer also to typical

VCO operating waveforms in Figure 37.

6V

5.1V

V_FB

1.2V

Ct_T_On

C_DT

DT

A

B

C_Dgs

SR_A

SR_B

FB_Fault

Operation

Fixed

Mode

Fop=Fmin

FB_Fault DT=50%

detected

Variable Fop

DT=50%

Figure 37. VCO Operating Waveforms

Fop = Fmax

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