RT9986 RICHTEK [Richtek Technology Corporation], RT9986 Datasheet - Page 21

• Manufacturer Part Number: RT9986
• Description: 7-CH DC/DC Converter for DSC
• Manufacturer: RICHTEK [Richtek Technology Corporation]

DS9986-00 May 2011
Figure 1. Derating Curves for RT9986 Packages
4.0
3.6
3.2
2.8
2.4
2.0
1.6
1.2
0.8
0.4
0.0
0
Place the feedback components as close as possible to
the FB pin and keep away from noisy devices.
Input/Output capacitors must be placed as
close as possible to the Input/Output pins.
GND
GND
LX6
V
V
D1
OUT_CH6
OUT_CH4
R7
R13
D4 D3
GND
C18
C15
25
R8
Ambient Temperature (°C)
C20
D2
R11
50
C10
C16
R12
GND
C19
L7
GND
VOUT6
PVDD7
C3
VREF
75
EN7
FB1
FB6
FB7
LX7
R2
C4
Four-Layers PCB
V
L4
BAT
1
2
3
4
5
6
7
8
C9
Figure 2. PCB Layout Guide
100
V
L1
32
OUT_CH1
9
V
C21
R1
BAT
10
31
125
30
11
LX should be connected to Inductor by wide and short
trace, keep sensitive components away from this trace
12
29
GND
C2
V
GND
Layout Consideration
For the best performance of the RT9986, the following
PCB layout guidelines must be strictly followed.
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BAT
13
28
L6
Place the input and output capacitors as close as
possible to the input and output pins respectively for
good filtering.
Keep the main power traces as wide and short as
possible.
The switching node area connected to LX and inductor
should be minimized for lower EMI.
Place the feedback components as close as possible
to the FB pin and keep these components away from
the noisy devices.
Connect the GND and Exposed Pad to a strong ground
plane for maximum thermal dissipation and noise
protection.
C6
14
27
33
15
26
V
L2
OUT_CH2
16
25
C7
L3
24
23
22
21
20
19
18
17
C22
FB2
SYSR
RTCPWR
VDDM
LX5
PVDD5
FB5
RST
C5
R3
GND
R10
L5
Connect the
Exposed Pad to
a ground plane.
R4
V
V
BAT
OUT_CH5
C8
V
C14
C12
C1
OUT_CH3
R9
R6
GND
GND
RT9986
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C13
R5
21