MB39C601 Datasheet, PDF (15/37 Pages) Cypress Semiconductor – High power factor in single conversion

MB39C601
8.6 OTM Part
It is set on-time by connecting resistor (ROTM) with the OTM pin. As shown in following figure, the on-time can be controlled by
connecting the collector of the Opto-Coupler through resistor from OTM.
OTM pin Control
The following figure shows how the on-time is programmed over the range of between 1.5μs and 5.0μs for either range of
programming resistors. The resistor range determines the controller response to a sustained overload fault (to either latch-off or to
shutdown/retry). See the item of the overload protection about details of "latch-off" and "shutdown/retry". On-time is related to the
programmed resistor based on the following equations.
(1) R_OTM = t_OTM × (2 × 10¹⁰ _[ ^Ω _{] )}
s
(2) R_OTM = t_OTM × (0.918 × 10¹¹ _[
Ω
])
s
On-time Setting Range
Moreover, it can be shutted down by making the voltage of the OTM pin below "VOTM (Vth) (typ 1V)".
Document Number: 002-08393 Rev.*A
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