LC

S1

CS

D

PA

LC

P

K

R

R

T

N

R

L

´

´

´

´

=

CCR

PS

CS

XFMR

OCC

V

N

R

2I

´

=

´

h

UCC28710, UCC28711, UCC28712, UCC28713, UCC28714, UCC28715, UCC28716

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SLUSB86B – NOVEMBER 2012 – REVISED JULY 2015

Feature Description (continued)

8.3.1.5 CS (Current Sense)

the internal comparator and MOSFET turn-off time. There is an internal leading-edge blanking time of 235 ns to

eliminate sensitivity to the MOSFET turn-on current spike. It should not be necessary to place a bypass capacitor

the energy stored in the transformer but not delivered to the secondary. This includes transformer resistance and

core loss, bias power, and primary-to-secondary leakage ratio.

Example: With a transformer core and winding loss of 5%, primary-to-secondary leakage inductance of 3.5%,

and bias power to output power ratio of 1.5%. The

where

•

•

•

•

(3)

where

•

•

•

•

•

•

(4)

8.3.1.6 CBC (Cable Compensation), Pin 1 UCC28700

The cable compensation pin is connected to a resistor to ground to program the amount of output voltage

compensation to offset cable resistance. The cable compensation block provides a 0-V to 3-V voltage level on

increases. There is an internal series resistance of 28 k

Ω to the CBC pin which sets a maximum cable

compensation of a 5-V output to 400 mV when CBC is shorted to ground. The CBC resistance value can be

determined by the equation below.

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