MAX8775 Datasheet, PDF (1/30 Pages) Maxim Integrated Products – Dual and Combinable Graphics Core Controller for Notebook Computers

19-0670; Rev 0; 11/06
EVAALVUAAILTAIOBNLEKIT
Dual and Combinable Graphics Core
Controller for Notebook Computers
General Description
The MAX8775 is a dual, step-down, interleaved, fixed-
frequency, switch-mode power-supply (SMPS) con-
troller with synchronous rectification. It is intended for
GPU cores and I/O power generation in battery-pow-
ered systems. Flexible configuration allows the
MAX8775 to operate as two independent single-phase
regulators, or as one high-current two-phase regulator.
Configured in separate mode, the MAX8775 provides
power to two dynamic voltage rails, one for the GPU
core and the other for the I/O power rail. Configured in
combined mode, the MAX8775 functions as a two-
phase, high-current, single-output GPU core regulator,
powering the high-performance GPU engines used in
gaming machines and media center notebooks.
The REFIN voltage setting allows for multiple dynamic
output voltages required by the different GPU operating
and sleep states. Automatic fault blanking, forced-PWM
operation, and transition control are achieved by
detecting the voltage change at REFIN. Fixed-frequen-
cy operation with 180° out-of-phase interleaving mini-
mizes input ripple current from the lowest input
voltages up to the 26V maximum input. Current-mode
control allows the use of low-ESR output capacitors.
Internal integrators maintain high output accuracy over
the full line-and-load range, in both forced-PWM mode
and pulse-skipping mode. True differential current
sensing provides accurate output current limit and cur-
rent balance when operated in combined mode.
Independent on/off and skip control allows flexible
power sequencing and power management. Voltage-
controlled soft-start reduces inrush current. Soft-stop
gradually ramps the output voltage down, preventing
negative voltage dips.
Applications
2 to 4 Li+ Cells Battery-Powered Devices
Media Center and Gaming Notebooks
GPU and I/O Power Supplies
Tracking Output Power Supplies
Features
o Dual-Output, Fixed-Frequency, Current-Mode
Control
o Combinable Output for Higher Currents
o Dynamic Output Voltages with Automatic Fault
Blanking and Transition Control
o True Out-of-Phase Operation
o True Differential Current Sense for Accurate
Current Limit and Current Balance
o 4V to 26V Input Range
o 100kHz to 600kHz Switching Frequency
o 0.5V to 2.5V Adjustable Outputs
o Internal Integrator for High Output Accuracy
o Stable with Low-ESR Output Capacitors
o Independent Selectable PWM and Skip-Mode
Operation
o Independent Power-Good Outputs
o Soft-Start and Soft-Stop
o 2.5V Precision Reference
o < 1µA Typical Shutdown Current
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
PKG
CODE
MAX8775ETJ+ -40°C to +85°C ^{32 Thin QFN}
5mm x 5mm
+Denotes lead-free package.
T3255-5
Pin Configuration
TOP VIEW
24 23 22 21 20 19 18 17
DH1 25
16 DH2
ON1 26
15 ON2
CSL1 27
14 CSL2
CSH1 28
SKIP1 29
MAX8775
13 CSH2
12 SKIP2
PGOOD1 30
11 PGOOD2
DTRANS 31
10 CCI2
SLEW1 32
9 SLEW2
1 2345678
THIN QFN
5mm x 5mm
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.