Manual

MAX8775
Dual and Combinable Graphics Core
Controller for Notebook Computers
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, V
IN
= 12V, SKIP_ = 0, ON_ = V
CC
= 5V, separate mode, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 6)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
INPUT SUPPLIES
V
IN
426
Input Voltage Range
V
BIAS
V
CC
, V
DD
4.5 5.5
V
V
CC
Undervoltage Lockout
V
UVLO
Rising edge, 200mV typical hysteresis 4.1 4.5 V
Quiescent Supply Current (V
CC
)I
CC
CSL_ forced above their regulation points 2.5 mA
Quiescent Supply Current (V
DD
)I
DD
CSL_ forced above their regulation points 5 µA
Shutdown Supply Current (V
CC
) ON1 = ON2 = GND 5 µA
Shutdown Supply Current (V
DD
) ON1 = ON2 = GND 5 µA
MAIN SMPS CONTROLLERS
PWM_ Output Voltage
V
REFIN_
-
V
CSL_
With respect to REFIN_,
REFIN_ = 0.5V to 2.5V,
SKIP_ = V
CC
or GND (Note 1)
-7.5 +7.5 mV
Output Voltage Adjust Range V
CSL_
Either SMPS (Note 2) 0.5 2.5 V
REFIN Operating Voltage Adjust
Range
V
REFIN_
Either SMPS (Note 2) 0.5 2.5 V
Combined Mode Enabled V
REFIN2
3V
R
OSC
= 143kΩ (f
OSC
= 300kHz nominal) -15 +15
Switching Frequency Accuracy
(Note 2)
f
OSC
R
OSC
= 71.5kΩ (f
OSC
= 600kHz nominal) to
432kΩ (f
OSC
= 99kHz nominal)
-20 +20
%
Maximum Duty Factor D
MAX
90 %
I
SLEW_
During transition 3.75 5.50
Slew-Rate Current
I
SLEWSS_
Startup and shutdown 0.7 1.2
µA
CURRENT LIMIT
Current-Limit Threshold V
LIMIT
V
CSH
_ - V
CSL
_2535mV
REFERENCE (REF)
Reference Voltage V
REF
V
CC
= 4.5V to 5.5V, I
REF
= 0 2.462 2.538 V
Refer ence S our ce Load Reg ul ati on ΔV
REF
I
REF
= 0µA to 250µA 2 mV
Reference Sink Load Regulation I
REF
= -50µA 10 mV
CURRENT BALANCE
Current-Balance Amplifier (GMI)
Offset
[V(CSH1,CSL1) - V(CSH2,CSL2)] at I
CCI
= 0 -3 +3 mV