MAX5066 Maxim Integrated Products, MAX5066 Datasheet - Page 21

• Manufacturer Part Number: MAX5066
• Description: Synchronous Buck Controller
• Manufacturer: Maxim Integrated Products

Calculate C
where C
The MAX5066 can be used to regulate two outputs
from one controller. Each of the two outputs can be
turned on and off independently of one another by con-
trolling the enable input of each phase (EN1 and EN2).
A logic-low on each enable pin shuts down the
MOSFET drivers for that phase. When the voltage on
the enable pin exceeds 1.2V, the drivers are turned on
and the output can come up to regulation. This method
of turning on the outputs allows the MAX5066 to be
used for power sequencing.
Careful PC board layout is critical to achieve low loss-
es, low output noise, and clean and stable operation.
This is especially true for dual-phase converters where
one channel can affect the other. Use the following
guidelines for PC board layout:
1) Place the V
2) Minimize all high-current switching loops.
3) Keep the power traces and load connections short.
4) Run the current-sense lines CSP_ and CSN_ very
5) Place the bank of output capacitors close to the
6) Isolate the power components on the top side from
7) Provide enough copper area around the switching
Configurable, Single-/Dual-Output, Synchronous
bypass capacitors close to the MAX5066.
This practice is essential for high efficiency. Use
thick copper PC boards (2oz or higher) to enhance
efficiency and minimize trace inductance and
resistance.
close to each other to minimize loop areas. Do not
cross these critical signal lines through power cir-
cuitry. Sense the current right at the pads of the
current-sense resistors.
load.
the analog components on the bottom side with a
ground plane in between.
MOSFETs, inductors, and sense resistors to aid in
thermal dissipation and reducing resistance.
Buck Controller for High-Current Applications
CFF
CFF
is C11 and C13 in Figure 6.
C
CFF
such that:
Applications Information
DD
Independant Turn-On and Off
______________________________________________________________________________________
=
PC Board Layout Guidelines
, REG, and the BST1 and BST2
2
× ×
π
f
C
1
×
10
×
R
CF
8) Distribute the power components evenly across the
9) Keep AGND and PGND isolated and connect them
10) Place all input bypass capacitors for each input as
TRANSISTOR COUNT: 6252
PROCESS: BiCMOS
TOP VIEW
*CONNECT EXPOSED PAD TO GROUND PLANE.
top side for proper heat dissipation.
at one single point close to the IC. Do not connect
them together anywhere else.
close to each other as is practical.
RT/CLKIN
EAOUT2
EAOUT1
MODE
AGND
CSN2
CSN1
CSP2
EAN2
CLP2
CLP1
EAN1
CSP1
REF
10
11
12
13
14
1
2
3
4
5
6
7
8
9
*EXPOSED PADDLE
MAX5066
TSSOP
Pin Configuration
Chip Information
28
27
26
25
24
23
22
21
20
19
18
17
16
15
EN2
BST2
DH2
LX2
DL2
PGND
IN
REG
V
DL1
LX1
DH1
BST1
EN1
DD
21