ML4835
REF
20
DURING PREHEAT
ICHG = 2.5V
RSET
AFTER PREHEAT
LEA_ENB = HI
ICHG = 5V – 7.5V
RSET
8K±25%
LEA_ENB = LOW
ICHG = 5V – LEAO
RSET
8K±25%
+
R
T2
R
T
I
CHG
8
R
T2
9
LEA_ENB
+
R
T
/C
T
3.75/1.25V
–
INTERRUPT
10
1.25/1.0V
V
CC
0.625
R
SET
R
X
/C
X
–
+
C
T
5.5mA
19
7.5V
NOTE 1: R
SET
SHOULD BE SELECTED SUCH THAT AFTER PREHEAT WITH LEA_ENB "HI",
I
CHG
MUST BE < 0.
I
CHG
IS A UNI-DIRECTIONAL SOURCE CURRENT ONLY.
11
–
+
4.75/1.25V
CLOCK
t
DIS
V
TH
= 3.75V
t
CHG
C
T
V
TL
= 1.25V
Figure 8. Oscillator Block Diagram and Timing
V
CC
VCCZ
V(ON)
V(OFF)
I
CC
5.5mA
t
0.34mA
t
Figure 9. Typical V
CC
and I
CC
Waveforms when the ML4835 is Started with a Bleed Resistor from
the Rectified AC Line and Bootstrapped from an Auxiliary Winding.
9