Richtek RT9953GQW Schematic [ru]
4+1 CH Power Management IC
RT9953
General Description
The RT9953 is a complete power supply solution for digital
still camera s a nd other handheld devices. The R T9953 is
a multi-CH power management IC including one
synchronous step-up DC/DC converter, one selectable
synchronous step-up/step-down DC/DC converter, two
synchronous step-down DC/DC converters, a nd one low
dropout linear regulator.
The RT9953 is designed to fulfill the a pplications f or DSC
as follows :
CH1 is a synchronous step-up output for motor or DSC
system I/O power
CH2 is a selectable synchronous step-up/step-down
output for motor or DSC system I/O power
CH3 and CH4 are synchronous step-down outputs for DSP
core and memory power supply
CH5 is a 500mA, low dropout, low noise linear regulator
with soft-start function.
The RT9953 is designed to support Li+ and 2AA battery
a pplications. The selectable step-up/step-down converter
can be set by SEL pin. For the synchronous step-up an d
step down converters, the efficiency ca n be up to 95%.
The RT9953 provides over current protection, thermal
shutdown protection, over voltage and under voltage
protection to achieve complete protection. The R T9953 is
available in the WQF N-24L 4x4 pa ckage.
Ordering Information
RT9953
Package Type
QW : WQFN-24L 4x4 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Richtek products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Features
zz
One Synchronous Step-Up/Step-Down Selectable
z
zz
Converter
zz
z Support 2AA or Li-ion Battery Applications
zz
zz
z Internal Soft-Start Control
zz
zz
z 4 CHs with Internal Compensation
zz
zz
z Power Switches Integrated
zz
zz
z Up to 95% Efficiency
zz
zz
z 100% (max) Duty Cycle for Step-Down Converter
zz
zz
z Adjustable Output Voltage
zz
zz
z Fixed 1MHz Switching Frequency
zz
zz
z LDO Works with Low-ESR Ceramic Capacitors
zz
zz
z Fast Line/Load Transient Response
zz
zz
z High PSRR Linear Regulator
zz
zz
z RoHS Compliant and Halogen Free
zz
Applications
z CMOS Digital Still Ca mera
z CMOS D V
z Portable Devices
Pin Configurations
(TOP VIEW)
FB5 FB2
11
EN4
25
PVDD5
SEL
LX3
18
17
16
15
14
13
LX2
PVDD2
VDDM
FB3
EN2
PVDD3
LX1
PVDD1
EN3
FB4
SS
PVDD4
EN1
GND
24 2223
1
2
3
4
5
6
7
8910 12
LX4
EN5
WQFN-24L 4x4
FB1
21 20 19
GND
VOUT5
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
DS9953-02 April 2011 www.richtek.com
1
RT9953
Typical Application Circuit
For 2AA
C10
10µF
C4
10µF
C12
33pF
V
2.2µH
R3
470k
R4
88.7k
4.7µH
BAT
V
OUT_CH4
1.8V
V
OUT_CH2
10µF
V
BAT
C11
3.6V
5V
C5
10µF x 2
R7
470k
R8
374k
C16
1µF
Chip Enable
23, 25 (Exposed Pad)
L2
L4
18
17
21
19
16
24
14
20
6
7
4
VDDM
3
8
LX2
PVDD2
FB2
PVDD43.6V
LX4
FB4
SEL
EN1
EN2
EN3
EN4
EN5
GND
RT9953
1
LX1 V
2
PVDD1
22
FB1
13
PVDD3
12
LX3
15
FB3
11
PVDD5 3.6V
9
VOUT5
10
FB5
5
SS
L3
4.7µH
L1
2.2µH
C3
4.7pF
C9
22pF
C15
10pF
C17
0.47nF
R1
470k
R2
133k
C1
10µF
C7
10µF
R5
768k
R6
360k
C13
1µF
R9
47k
R10
22.1k
C2
10µF x 2
C8
10µF
C14
1µF
BAT
V
OUT_CH1
3.6V
3.6V
V
OUT_CH3
2.5V
V
OUT_CH5
2.5V
DS9953-02 April 2011www.richtek.com
2
For Li-ion
RT9953
V
OUT_CH2
V
OUT_CH4
V
BAT
or 5V
3.3V
1.8V
C5
10µF
V
C11
10µF
BAT
5V
C4
10µF
L2
2.2µH
R3
470k
R4
150k
R7
470k
R8
374k
C6
10pF
C10
10µF
C16
1µF
Chip Enable
23, 25 (Exposed Pad)
4.7µH
C12
33pF
L4
16
17
18
21
6
7
4
19
24
14
3
20
8
PVDD2
LX2
FB2
PVDD4
LX4
FB4
SEL
VDDM
EN1
EN2
EN3
EN4
EN5
GND
RT9953
L1
L3
4.7µH
2.2µH
C3
4.7pF
C17
0.47nF
C9
22pF
C15
10pF
R1
470k
R2
88.7k
C1
10µF
C7
10µF
R5
768k
R6
360k
C13
1µF
R9
47k
R10
22.1k
C2
10µF x 2
1
LX1 V
2
PVDD1
22
FB1
13
PVDD3
12
LX3
15
FB3
11
PVDD5
9
VOUT5
10
FB5
5
SS
C8
10µF
C14
1µF
BAT
V
OUT_CH1
5V
V
BAT
V
OUT_CH3
2.5V
V
BAT
V
OUT_CH5
2.5V
DS9953-02 April 2011 www.richtek.com
3
RT9953
Channel CH3
Table 1. Recommended Components for the Typical Application Circuit
Formula V
V
OUT_CH3
L3 (µH) 4.7 4.7 4.7 4.7 4.7 4.7 4.7
R5 (kΩ) 86.6 768 470 330 237 187 23.2
R6 (kΩ) 27.4 360 374 374 374 374 93.1
C9 (pF) 22 22 33 47 68 82 47
C8 (µF) 10 10 10 10 10 10 10
(V) 3.3 2.5 1.8 1.5 1.3 1.2 1.0
OUT_CH3
= (1+R5/R6) x 0.8
Channel CH4
Application
V
OUT_CH4
L4 (µH)
R7 (kΩ) 86.6 768 470 330 237 187 23.2
R8 (kΩ) 27.4 360 374 374 374 374 93.1
C12 (pF) 22 22 33 47 68 82 47
C11 (µF) 10 10 10 10 10 10 10
(V)
3.3 2.5 1.8 1.5 1.3 1.2 1.0
4.7 4.7 4.7 4.7 4.7 4.7 4.7
V
OUT_CH4
= (1+R7/R8) x 0.8
Channel CH5
Formula V
V
OUT_CH5
R9 (kΩ) 47
R10 (kΩ) 22.1
C15 (pF) 10
C14 (µF) 1
(V) 2.5
OUT_CH5
= (1+R9/R10) x 0.8
DS9953-02 April 2011www.richtek.com
4
Functional Pin Description
Pin No. Pin Name
1 LX1 Switch Node of CH1. High impedance in shutdown mode.
2 PVDD1 Power Input of CH1.
3 EN3 Enable Control Input of CH3.
4 FB4 Feedback Input of CH4. High impedance in shutdown mode.
5 SS Soft-Start Control Input.
6 PVDD4 Power Input of CH4.
7 LX4 Switch Node of CH7. High impedance in shutdown mode.
8 EN5 Enable Control Input of CH5.
9 VOUT5 Output Voltage of CH5.
10 FB5 Feedback Input of CH5. High impedance in shutdown mode.
11 PVDD5 Power Input of CH5.
12 LX3 Switch Node of CH3. High impedance in shutdown mode.
13 PVDD3 Power Input of CH3.
14 EN2 Enable Control Input of CH2.
15 FB3 Feedback Input of CH3. High impedance in shutdown mode.
16 VDDM Analog Power Input.
17 PVDD2 Power Input of CH2.
RT9953
Pin Function
18 LX2 Switch Node of CH2. High impedance in shutdown mode.
19 SEL
20 EN4 Enable Control Input of CH4.
21 FB2 Feedback Input of CH2. High impedance in shutdown mode.
22 FB1 Feedback Input of CH1. High impedance in shutdown mode.
23,
25 (Exposed Pad)
24 EN1 Enable Control Input of CH1.
GND
Selection Input for CH2 step-up or step-down operation mode. Logic state can
not be changed during operation.
Ground Pin. The exposed pad must be soldered to a large PCB and connected to
GND for maximum thermal dissipation.
DS9953-02 April 2011 www.richtek.com
5
RT9953
Function Block Diagram
VDDM
PVDD2
LX2
FB2
PVDD4
LX4
FB4
EN1
EN2
EN3
EN4
EN5
SEL
0.8V
REF
0.8V
REF
CH2
C-Mode
Step-Up or
Step-Down
+
CH4
C-Mode
Step-Down
+
Enable Mode
Sequence
CH1
C-Mode
Step-Up
CH3
C-Mode
Step-Down
VDDM
CH5
LDO
PVDD1
LX1
-
+
0.8V
REF
+
0.8V
REF
+
0.8V
REF
FB1
PVDD3
LX3
FB3
PVDD5
SS
VOUT5
FB5
GND
DS9953-02 April 2011www.richtek.com
6
Loading...