MAX1544ETL+T Maxim Integrated Products, MAX1544ETL+T Datasheet - Page 25

• Manufacturer Part Number: MAX1544ETL+T
• Description: IC QUICK-PWM DUAL-PHASE 40-TQFN
• Manufacturer: Maxim Integrated Products
• Series: Quick-PWM™r

Specifications of MAX1544ETL+T

• Applications: Controller, AMD Hammer
• Voltage - Input: 2 ~ 28 V
• Number Of Outputs: 1
• Voltage - Output: 0.68 ~ 1.55 V
• Operating Temperature: -40°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: 40-TQFN Exposed Pad
• Output Voltage: 0.675 V to 1.55 V
• Output Current: 40 A
• Input Voltage: 4 V to 28 V
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 100 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

where I
f
Q
specification limits at V
V+ and V
source is a fixed 4.5V to 5.5V supply. If the 5V bias
supply is powered up prior to the battery supply, 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 whose period is 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).
Table 5. Suspend Mode DAC Codes
*Connect the three-level SUS input to a 2.7V or greater supply (3.3V or V
SW
G(HIGH)
SUS*
High
High
High
High
High
High
High
High
High
High
High
High
High
High
High
High
is the switching frequency, and Q
Free-Running, Constant-On-Time PWM
CC
are the MOSFET data sheet’s total gate-charge
DD
Controller with Input Feed Forward
is provided in the Electrical Characteristics,
can be tied together if the input power
LOWER SUSPEND CODES
OPEN
OPEN
OPEN
OPEN
GND
GND
GND
GND
REF
REF
REF
REF
V
V
V
V
S1
CC
CC
CC
CC
______________________________________________________________________________________
AMD Hammer CPU Core Power Supplies
GS
Dual-Phase, Quick-PWM Controller for
= 5V.
OPEN
OPEN
OPEN
OPEN
GND
GND
GND
GND
REF
V
REF
V
REF
V
REF
V
S0
CC
CC
CC
CC
VOLTAGE
OUTPUT
G(LOW)
0.675
0.700
0.725
0.750
0.775
0.800
0.825
0.850
0.875
0.900
0.925
0.950
0.975
1.000
1.025
1.050
(V)
and
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.
The core of each phase contains a fast, low-jitter,
adjustable one-shot that sets the high-side MOSFETs
on-time. The one-shot for the main phase varies the on-
time in response to the input and feedback voltages.
The main high-side switch on-time is inversely propor-
tional to the input voltage as measured by the V+ input,
and proportional to the feedback voltage (V
where K is set by the TON pin-strap connection (Table 6)
and 0.075V is an approximation to accommodate the
expected drop across the low-side MOSFET switch.
CC
SUS*
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
REF
) for an input logic level high.
t
ON MAIN
(
UPPER SUSPEND CODES
OPEN
OPEN
OPEN
OPEN
GND
GND
GND
GND
REF
REF
REF
REF
V
V
V
V
S1
CC
CC
CC
CC
)
=
On-Time One-Shot (TON)
K V
(
FB
OPEN
OPEN
OPEN
OPEN
GND
GND
GND
GND
REF
V
REF
V
REF
V
REF
V
S0
V
+
CC
CC
CC
CC
IN
0 075
.
V
)
VOLTAGE
OUTPUT
FB
1.075
1.100
1.125
1.150
1.175
1.200
1.225
1.250
1.275
1.300
1.325
1.350
1.375
1.400
1.425
1.450
):
(V)
25