MAX17582GTM+ Maxim Integrated Products, MAX17582GTM+ Datasheet - Page 24

• Manufacturer Part Number: MAX17582GTM+
• Description: IC PWM CTRLR STP-DN DL 48TQFN
• Manufacturer: Maxim Integrated Products
• Series: Quick-PWM™r

Specifications of MAX17582GTM+

• Applications: Controller, Intel IMVP-6.5™
• Voltage - Input: 4.5 ~ 5.5 V
• Number Of Outputs: 1
• Voltage - Output: 0.01 ~ 1.5 V
• Operating Temperature: -40°C ~ 105°C
• Mounting Type: Surface Mount
• Package / Case: 48-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Dual-Phase, Quick-PWM Controller for
IMVP-6.5 CPU Core Power Supplies
The MAX17582 includes differential, remote-sense
inputs to eliminate the effects of voltage drops along the
PCB traces and through the processor’s power pins. The
feedback-sense node connects to the voltage-position-
ing resistor (R
nects to an amplifier that adds an offset directly to the
target voltage, effectively adjusting the output voltage to
counteract the voltage drop in the ground path. Connect
the voltage-positioning resistor (R
(GNDS) input directly to the processor’s remote-sense
outputs, as shown in Figure 1.
An integrator amplifier forces the DC average of the FB
voltage to equal the target voltage. This transconduc-
tance amplifier integrates the feedback voltage and pro-
vides a fine adjustment to the regulation voltage (Figure
2), allowing accurate DC output-voltage regulation
regardless of the output ripple voltage. The integrator
amplifier can shift the output voltage by ±100mV (typ).
The differential input-voltage range is at least ±60mV
total, including DC offset and AC ripple.
The MAX17582 disables the integrator by connecting
the amplifier inputs together at the beginning of all VID
transitions done in pulse-skipping mode (DPRSLPVR =
high). The integrator remains disabled until 20μs after
the transition is completed (the internal target settles)
and the output is in regulation (edge detected on the
error comparator).
When a transient occurs, the response time of the con-
troller depends on how quickly it can slew the inductor
current. Multiphase controllers that remain 180° out-of-
phase when a transient occurs actually respond slower
than an equivalent single-phase controller. To provide
fast-transient response, the MAX17582 supports a
phase-overlap mode, which allows the dual regulators
to operate in-phase when heavy load transients are
detected, effectively reducing the response time. After
either high-side MOSFET turns off, if the output voltage
does not exceed the regulation voltage when the mini-
mum off-time expires, the controller simultaneously
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FB
). The ground-sense (GNDS) input con-
Transient-Overlap Operation
Differential Remote Sense
FB
Integrator Amplifier
) and ground-sense
turns on both high-side MOSFETs during the next on-
time cycle. This maximizes the total inductor current
slew rate. The phases remain overlapped until the out-
put voltage exceeds the regulation voltage after the
minimum off-time expires.
After the phase-overlap mode ends, the controller automat-
ically begins with the opposite phase. For example, if the
secondary phase provided the last on-time pulse before
overlap operation began, the controller starts switching
with the main phase when overlap operation ends. Table 3
is the operating mode truth table.
The nominal no-load output voltage (V
defined by the selected voltage reference (VID DAC)
plus the remote ground-sense adjustment (V
defined in the following equation:
where V
MAX17582 slews the target voltage from ground to the
preset boot voltage.
The digital-to-analog converter (DAC) programs the out-
put voltage using the D0–D6 inputs. D0–D6 are low-
voltage (1.0V) logic inputs, designed to interface directly
with the CPU. Do not leave D0–D6 unconnected.
Changing D0–D6 initiates a transition to a new output-
voltage level. Change D0–D6 together, avoiding greater
than 20ns skew between bits. Otherwise, incorrect DAC
readings might cause a partial transition to the wrong volt-
age level followed by the intended transition to the correct
voltage level, lengthening the overall transition time. The
available DAC codes and resulting output voltages are
compatible with the IMVP-6.5 (Table 4) specifications.
DAC
V
Nominal Output-Voltage Selection
TARGET
is the selected VID voltage. On startup, the
= V
FB
= V
DAC
DAC Inputs (D0–D6)
+ V
GNDS
TARGET
GNDS
) as
) is