TL284X_07 Datasheet, PDF (8/18 Pages) Texas Instruments – CURRENT-MODE PWM CONTROLLERS

TL284x, TL384x
CURRENT-MODE PWM CONTROLLERS
SLVS038F – JANUARY 1989 – REVISED FEBRUARY 2003
APPLICATION INFORMATION
2.5 V
Error
Amplifier
VFB
+
Zi
–
Zf
COMP
0.5 mA
NOTE A: Error amplifier can source or sink up to 0.5 mA.
Figure 1. Error-Amplifier Configuration
IS
(see Note A)
Error
Amplifier
+
–
Rf
RS
COMP
ISENSE
Cf
GND
2R
R
1V
Current-Sense
Comparator
NOTE A: Peak current (IS) is determined by the formula:
+ I_S(max)
1V
R_S
A small RC filter formed by resistor Rf and capacitor Cf may be required to suppress switch transients.
Figure 2. Current-Sense Circuit
[ NOTE A: For RT > 5 kΩ: f
1.72
R_TC_T
REF
RT/CT
GND
RT
(see Note A)
CT
Figure 3. Oscillator Section
8
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