THV3011_Rev.1.00_E
●
Setting the Output Voltage
THV3011 detects the output ripple voltage. When the output voltage reaches to the voltage defined
by
R
2
+
R
3
(between output capacitor and FB pin) and
R
4
( between FB pin and GND) as following
formula, LL pin is turned from Low to High level for a constant time.
V
OUT
_
bottom
=
⎛
R
+
R
3
V
FB
×
⎜
1
+
2
⎜
R
4
⎝
⎞
⎟
⎟
⎠
DC output voltage at the continuous mode is calculated as following formula, adding the average of the ripple
voltage (
I
×
R
).
rip
ESR
V
OUT
⎛
R
2
+
R
3
⎞
⎟
×0.85V
+
1
I
RIP
R
ESR
=
⎜
1
+
⎜
2
R
4
⎟
⎝
⎠
Output
R2
R3
FB
R4
GND
●
Power Stand-by Indicator (PSI)
Continuous/Light Load modes are selectable by PSI pin, High or Low. High = continuous mode, Low = light
load mode. LG pin is held Low and stops the operation of Low side FET in the light load mode.
●
Output Pull-Down
THV3011 has a built-in Output Pull-Down function to shorten the output fall time. When CTL pin is turned to
Low, an internal transistor connected between CSP pin and GND start to discharge the output capacitor.
●
Setting the Oscillation Frequency (FSET)
User can choose Oscillation frequency 360kHz or 500kHz by adjusting the voltage on FSET pin. High =
360kHz(typ), Open = 500kHz(typ).
Copyright©2009 THine Electronics, Inc.
9/12
THine Electronics, Inc.
THINE [ THINE ELECTRONICS, INC. ]
