AIC3843 Datasheet, PDF (5/11 Pages) Analog Intergrations Corporation – Current-Mode PWM Controller

Error AMP Configuration
Z_I
Under-Voltage Lockout
7
2.50V
0.5mA
+
V_FB
-
2
COMP
Z_{F 1}
Error Amp can Source or Sink up to 0.5mA
Fig. 1
I_CC
AIC3843
AIC3843
17mA
V _ON
8.4V
500µA
V OFF
7.6V
V _CC
Fig. 2-1
Fig. 2-2
V_{OFF VON}
During under-voltage lockout, the output driver is biased to sink minor amounts of
current. Pin 6 should be shunted to ground with a bleeder resistor to prevent
activating the power switch with extraneous leakage currents.
Current Sense Circuit
Error AMP
I_S
R
R_S
COMP
C
Current Sense
GND
2R
R
1V
Current Sense
Comparator
Peak Current (Is) is Determined By The Formula
I_SMAX≈ 1.0V
R_S
A small RC filter may be required to suppress switch transients.
Fig. 3
5