MAX8760ETL+T Maxim Integrated Products, MAX8760ETL+T Datasheet - Page 24

• Manufacturer Part Number: MAX8760ETL+T
• Description: IC CNTRLR QUICK PWM 40-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8760ETL+T

• Applications: Controller, 6-bit VID AMD Mobile Turion™
• Voltage - Input: 4 ~ 28 V
• Number Of Outputs: 2
• Voltage - Output: 0.38 ~ 1.55 V
• Operating Temperature: 0°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 40-TQFN Exposed Pad
• Output Voltage: 0.375 V to 1.55 V
• Output Current: 4000 mA
• Mounting Style: SMD/SMT
• Switching Frequency: 550 KHz
• Maximum Operating Temperature: + 100 C
• Minimum Operating Temperature: - 40 C
• Synchronous Pin: No
• Topology: Buck
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The Quick-PWM controller requires an external 5V bias
supply in addition to the battery. Typically, this 5V bias
supply is the notebook’s 95%-efficient 5V system sup-
ply. Keeping the bias supply external to the IC
improves efficiency and eliminates the cost associated
with the 5V linear regulator that would otherwise be
needed to supply the PWM circuit and gate drivers. If
stand-alone capability is needed, the 5V bias supply
can be generated with an external linear regulator.
The 5V bias supply must provide V
and V
drawn is:
where I
table, f
Q
specification limits at V
V+ and V
power source is a fixed 4.5V to 5.5V supply. If the 5V
bias supply is powered up prior to the battery supply,
Dual-Phase, Quick-PWM Controller for AMD
Mobile Turion 64 CPU Core Power Supplies
Table 5. Suspend Mode DAC Codes
*Connect the tri-level SUS input to a 2.7V or greater supply (3.3V or V
24
G(HIGH)
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
HIGH
SUS
______________________________________________________________________________________
DD
SW
CC
I
BIAS
are the MOSFET data sheet’s total gate-charge
(gate-drive power), so the maximum current
DD
is the switching frequency, and Q
is provided in the Electrical Characteristics
= I
can be connected together if the input
OPEN
OPEN
OPEN
OPEN
LOWER SUSPEND CODES
CC
GND
GND
GND
GND
REF
REF
REF
REF
V
V
V
V
S1
5V Bias Supply (V
CC
CC
CC
CC
Multiphase Quick-PWM
+ f
SW
GS
(Q
= 5V.
G(LOW)
OPEN
OPEN
OPEN
OPEN
GND
GND
GND
GND
REF
V
REF
V
REF
V
REF
V
S0
CC
CC
CC
CC
+ Q
CC
(PWM controller)
G(HIGH)
VOLTAGE (V)
CC
OUTPUT
0.800
0.775
0.750
0.725
0.700
0.675
0.650
0.625
0.600
0.575
0.550
0.525
0.500
0.475
0.450
0.425
and V
G(LOW)
)
DD
and
)
CC
the enable signal (SHDN going from low to high) must
be delayed until the battery voltage is present to ensure
startup.
The Quick-PWM control architecture is a pseudofixed-
frequency, constant-on-time, current-mode regulator with
input voltage feed-forward (Figure 5). This architecture
relies on the output filter capacitor’s ESR to act as the
current-sense resistor, so the output ripple voltage pro-
vides the PWM ramp signal. The control algorithm is sim-
ple: the high-side switch on-time is determined solely by
a one-shot with a period inversely proportional to input
voltage, and directly proportional to output voltage or the
difference between the main and secondary inductor
currents (see the On-Time One-Shot (TON) section).
Another one-shot sets a minimum off-time. The on-time
one-shot triggers when the error comparator goes low,
the inductor current of the selected phase is below the
valley current-limit threshold, and the minimum off-time
one-shot times out. The controller maintains 180° out-of-
phase operation by alternately triggering the main and
secondary phases after the error comparator drops
below the output voltage set point.
) for an input logic level high.
SUS
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
Free-Running, Constant-On-Time PWM
Controller with Input Feed-Forward
OPEN
OPEN
OPEN
OPEN
UPPER SUSPEND CODES
GND
GND
GND
GND
V
V
V
V
REF
REF
REF
REF
S1
CC
CC
CC
CC
OPEN
OPEN
OPEN
OPEN
GND
GND
GND
GND
REF
V
REF
V
REF
V
REF
V
S0
CC
CC
CC
CC
VOLTAGE (V)
OUTPUT
1.200
1.175
1.150
1.125
1.100
1.075
1.050
1.025
1.000
0.975
0.950
0.925
0.900
0.875
0.850
0.825