rt9911 Richtek Technology Corporation, rt9911 Datasheet - Page 22
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rt9911
Manufacturer Part Number
rt9911
Description
6 Channel Dc/dc Converters
Manufacturer
Richtek Technology Corporation
Datasheet
1.RT9911.pdf
(32 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
rt9911PQV
Manufacturer:
NICHICON
Quantity:
40 000
RT9911
Note :
Calculation method:
Td1 to Td6 are precise value. Tr1 to Tr6 are approximation.
Units : T in second, C in Farad, R in Ohm
C31 to C36 : Compensation capacitor of CH1 to CH6.
T1d = 0.7V x C31 / 2uA (CH1 Boost)
T1d = 0.7V x C31 / 2uA (CH1 Buck)
T2d = 0.35V x C32 / 2uA
T3d = 0.7V x C33 / 2uA
T4d = 0.35V x C34 / 2uA
T5d = 0.85V x C35 / 2uA
T6d = 0.85V x C36 / 2uA
T1r = (0.5V x D1 + 0.48A x R
load (Boost)
T1r = (0.33V x D1 + 0.2A x R
load (Buck)
T2r = (0.33V x D2 + 0.2A x R
load
www.richtek.com
22
Please refer to Figure 1 for application Information.
Timing sequence should be controlled by EN pins.
DS(ON)_N
DS(ON)_P
DS(ON)_P
VDDM (VS 3.3V)
V
EN1 to EN6
CORE
CCD - 8V
CCD 12V
V
Motor 5V
VS 3.3V
I/O
x C31 /1.25uA @ No
x C32 /1.25uA @ No
x C31 /1.25uA @ No
WLED
V
1.8V
3.3V
BAT
Figure 4. Timing Diagram
T5d T5r
T2d T2r
T4d
T1d
T4r
T3d
T1r
T6d
T3r = (0.5V x D3 + 0.8A x R
load
T4r = (1.0V x D4) x C34 / 1uA @ No load
T5r = (1.0V x D5) x C35 / 1uA @ 1mA min. load
T6r = (0.25V x D6) x C36 / 2.6uA @ 4 WLEDs
where
D1 = 1 − (V
D1 = V
D2 = V
D3 = 1 − (V
D4 = 1 − (V
D5 = |V
D6 = 1 − (V
Example : T1d = 0.7V x 1nF / 2uA = 350 us (Boost)
T1r = (0.5 x (1−1.8/3.3) + 0.48 x 0.2) x 1nF / 1.25uA =
258 us
T3r
VS 3.3V
VCORE 1.8V
CCD -8V
T6r
BAT
BAT
BAT
BAT
/ V
| / ( V
/ V
/ V
/ V
/ V
BAT
/ V
Motor 5V
WLED
VS 3.3V
CCD 12V
BAT
BAT
)
+ |V
(Buck)
) (Boost)
)
)
CCD -8V
DS(ON)_N
DS9911-04 August 2007
|)
x C33 /3.6uA @ No