MAX8734 Maxim Integrated Products, MAX8734 Datasheet - Page 31

• Manufacturer Part Number: MAX8734
• Description: (MAX8732 - MAX8734) Main Power-Supply Controllers
• Manufacturer: Maxim Integrated Products

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4) Make the DC-DC controller ground connections as
5) On the board’s top side (power planes), make a
6) Connect the output power planes (V
follows: near the device, create a small analog
ground plane. Connect the small analog ground
plane to GND (Figure 13) and use the plane for the
ground connection for the REF and V
capacitors, FB dividers, and ILIM resistors (if any).
Create another small ground island for PGND, and
use the plane for the V+ bypass capacitor, placed
very close to the device. Connect the AGND and
PGND planes together at the GND pin of the device.
star ground to minimize crosstalk between the two
sides. The top-side star ground is a star connection
of the input capacitors and synchronous rectifiers.
Keep the resistance low between the star ground
and the source of the synchronous rectifiers for
accurate current limit. Connect the top-side star
ground (used for MOSFET, input, and output
capacitors) to the small island with a single short,
wide connection (preferably just a via).
Create PGND islands on the layer just below the
top-side layer (refer to the MAX1999 EV kit for an
example) to act as an EMI shield if multiple layers
are available (highly recommended). Connect each
of these individually to the star ground via, which
connects the top side to the PGND plane. Add one
more solid ground plane under the device to act as
an additional shield, and also connect the solid
ground plane to the star ground via.
ground planes) directly to the output filter capacitor
positive and negative terminals with multiple vias.
Supply Controllers for Notebook Computers
High-Efficiency, Quad-Output, Main Power-
______________________________________________________________________________________
CORE
CC
and system
bypass
TRANSISTOR COUNT: 8335
PROCESS: BiCMOS
Pin Configurations (continued)
TOP VIEW
PGOOD
SHDN
ILIM3
ILIM5
BST5
SKIP
CS3
ON3
ON5
PRO
CS5
FB3
REF
FB5
10
11
12
13
14
1
2
3
4
5
6
7
8
9
MAX8732
MAX8733
QSOP
Chip Information
28
27
26
25
24
23
22
21
20
19
18
17
16
15
BST3
LX3
DH3
LDO3
DL3
GND
OUT3
OUT5
V+
DL5
LDO5
V
DH5
LX5
CC
31