MAX1519 Datasheet, PDF (38/43 Pages) Maxim Integrated Products – Dual-Phase, Quick-PWM Controllers for Programmable CPU Core Power Supplies

Dual-Phase, Quick-PWM Controllers for
Programmable CPU Core Power Supplies
2) Group the gate-drive components (BST diodes
and capacitors, V_DD bypass capacitor) together
near the controller IC.
3) Make the DC-to-DC controller ground connections
as shown in the Standard Application Circuits.
This diagram can be viewed as having four sepa-
rate ground planes: input/output ground, where all
the high-power components go; the power ground
plane, where the PGND pin and V_DD bypass
capacitor go; the master’s analog ground plane,
where sensitive analog components, the master’s
GND pin, and V_CC bypass capacitor go; and the
slave’s analog ground plane, where the slave’s
GND pin and V_CC bypass capacitor go. The mas-
ter’s GND plane must meet the PGND plane only
at a single point directly beneath the IC. Similarly,
the slave’s GND plane must meet the PGND plane
only at a single point directly beneath the IC. The
respective master and slave ground planes
should connect to the high-power output ground
with a short metal trace from PGND to the source
of the low-side MOSFET (the middle of the star
ground). This point must also be very close to the
output capacitor ground terminal.
4) Connect the output power planes (V_CORE and
system ground planes) directly to the output filter
capacitor positive and negative terminals with
multiple vias. Place the entire DC-to-DC converter
circuit as close to the CPU as is practical.
Chip Information
TRANSISTOR COUNT: 11,015
PROCESS: BiCMOS
38 ______________________________________________________________________________________