RT9917 Datasheet, PDF (4/20 Pages) Richtek Technology Corporation – 7 Channel DC/DC Converters

RT9917
For 2AA
V_BAT
3.3V
C24
10uF _L1
2.2uH
40 _LX1
1uF
29
VDDM
V_OUT
3.3V
C1
10uF
AO3415
R1
Q1
1M
V_BAT
C19 ^5V
10uF
C3
10uFx2
3.3V
C22
10uF
2.5V
C4
22pF
3.3V
C23 ^1.8V
10uF
C6
33pF
R13
470k
R14
150k
C17
4.7pF
C18
560pF
R15
39k
L4
2.2uH
R16
470k
R17
88.7k
C21
560pF
R18
39k
R3
768k
R4
360k
L2
4.7uH
C5
10uF
R5
470k
L3
4.7uH
C7
10uF
R6
374k
Power On
ON
OFF
Dimming
1 _PVDD1
37
FB1
38 _COMP1
36 _OK134
35 _VOUT1
31 _LX2
30 _PVDD2
34 _FB2
33 _COMP2
20 _PVDD3
21 _LX3
23
FB3
11 _PVDD4
10 _LX4
8
FB4
39 _EN134
32 _EN2
12 _EN5
19 _EN6
22 _EN7
RT9917
V_BAT
LX5 ²⁵
SW5O ¹³
SW5I ¹⁴
FB5 ¹⁵
LX6 ²
GND ²⁷
FB6 ⁷
VREF ¹⁶
COMP6 ⁹
PVDD6 ³
LX7 ²⁶
VOUT7 ²⁴
CFB7 ²⁸
CP ⁴
CN
CPO
5
6
SEQ ¹⁸
SEL ¹⁷
C25
L5
1uF
10uH
16V
C8
10uF/25V
C24
10uF/25V
C9
R7
1nF _887k
L7
10uH
R8
75k
-8V
C12
R10
68k
4.7uF/16V
R11 C13
10.5k 0.1uF
R12
75k
C11
C14
47pF
1nF
C26
1uF
L6
10uH
V_BAT
C27
1uF
V_BAT
C15
0.1uF
V_BAT
D1
D2
D3
D4
R9
10
C16
1uF
C10
1uF/16V
Note : A schottky diode connect from LX1 to PVDD1 is required for low-voltage start up.
Timing Diagram
Power On Sequence : CH1 Boost 3.3V→ CH3 Buck 2.5V → CH4 Buck 1.8V → (CH2 Boost 5V and SW1 3.3V)
Power Off Sequence : (CH2 Boost 5V and SW1 3.3V)^→ CH4 Buck 1.8V ^→ CH3 Buck 2.5V ^→ CH1 Boost 3.3V
VDDM
EN134, EN2
CH1 V_OUT 3.3V
CH3 V_OUT 2.5V
CH4 V_OUT 1.8V
V_OUT1 3.3V
CH2 V_OUT 5V
User define
3.5ms
3.5ms
3.5ms
3.5ms
3.5ms
IC shutdown
Wait until FB3 < 0.1V
Wait until FB4 < 0.1V
Wait until V_OUT1 < 0.4V
Depends on loading
www.richtek.com
4
DS9917-03 April 2011