MAX17009GTL+ Maxim Integrated Products, MAX17009GTL+ Datasheet - Page 22

• Manufacturer Part Number: MAX17009GTL+
• Description: IC CTLR VIDEO SERIAL DUAL 40TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX17009GTL+

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX17009 interleaves both phases—resulting in
180° out-of-phase operation that minimizes the input and
output filtering requirements, reduces electromagnetic
interference (EMI), and improves efficiency. The high-
side MOSFETs do not turn on simultaneously during nor-
mal operation. The instantaneous input current is
effectively reduced by the number of active phases,
resulting in reduced input-voltage ripple, ESR power loss,
and RMS ripple current (see the Input-Capacitor
Selection section). Therefore, the controller achieves high
performance while minimizing the component count,
which reduces cost, saves board space, and lowers
component power requirements, making the MAX17009
ideal for high-power, cost-sensitive applications.
When a transient occurs, the output-voltage deviation
depends on the controller’s ability to quickly detect the
transient and slew the inductor current. A fixed-fre-
quency controller typically responds only when a clock
edge occurs, resulting in a delayed transient response.
To minimize this delay time, the MAX17009 includes
enhanced transient detection and transient- phase-
repeat capabilities. If the controller detects that the out-
put voltage has dropped by 25mV, the transient-
detection comparator immediately retriggers the phase
that completed its on-time last. The controller triggers
the subsequent phases as normal on the appropriate
oscillator edges. This effectively triggers a phase a full
cycle early, increasing the total inductor-current slew
rate and providing an immediate transient response.
The OPTION pin setting enables or disables the tran-
sient phase-repeat feature. Keep OPTION OPEN or
connected to GND to enable transient-phase repeat.
Connect OPTION to V
phase repeat. See the Offset and Transient-Phase
Repeat (OPTION) section.
Each of the MAX17009 SMPS controllers includes two
transconductance amplifiers—one for steady-state DC
droop, and another for AC droop. The amplifiers’ inputs
are generated by summing their respective current-sense
inputs, which differentially sense the voltage across either
current-sense resistors or the inductor’s DCR.
The DC droop amplifier’s output (FBDC) connects to
the remote-sense point of the output through a resistor
that sets each phase’s DC voltage-positioning gain:
AMD Mobile Serial VID Dual-Phase
Fixed-Frequency Controller
22
______________________________________________________________________________________
Interleaved Multiphase Operation
V
Feedback Adjustment Amplifiers
OUT
=
V
Steady-State Voltage-Positioning
TARGET
CC
or REF to disable transient-
−
Transient-Phase Repeat
R
FBDC FBDC
Amplifier (DC Droop)
I
where the target voltage (V
Nominal Output-Voltage Selection section, and the
FBDC amplifier’s output current (I
by each phase’s current-sense voltage:
where V
sense voltage, and G
defined in the Electrical Characteristics table.
DC droop is typically used together with the +12.5mV
offset feature to keep within the DC tolerance window of
the application. See the Offset and Transient-Phase
Repeat ( OPTION) section. The ripple voltage on FBDC
must be less than the 18mV (min) transient phase
repeat threshold:
where ΔI
effective output ESR at the remote sense point, R
the current-sense element, and G
(max) as defined in the Electrical Characteristics table.
The worst-case inductor ripple occurs at the maximum
input voltage and the minimum output-voltage conditions:
To disable voltage positioning, set R
The AC droop amplifier’s output (FBAC) connects to
the remote-sense point of the output through a resistor
that sets each phase’s AC voltage-positioning gain:
where the target voltage (V
Nominal Output-Voltage Selection section, and the
FBAC amplifier’s output current (I
by each phase’s current-sense voltage:
where V
sense voltage, and G
defined in the Electrical Characteristics table.
AC droop is required for stable operation of the
MAX17009. A minimum of 1mV/A is recommended. AC
droop must not be disabled.
Transient Voltage-Positioning Amplifier (AC Droop)
Δ
R
ΔI
I R
L SENSE m FBDC FBDC
FBDC
L MAX
CS
CS
(
L
is the inductor ripple current, R
= V
= V
V
≤
OUT
)
⎛
⎜
⎝
=
CSP
CSP
18
G
I
V
FBDC
I
Δ
FBAC
OUT MIN
=
mV
I
L
(
V
- V
- V
TARGET
(
−
=
=
CSN
CSN
M(FBAC)
R
M(FBDC)
G
)
G
ESR
R
V
m FBDC CS
)
m FBAC CS
(
IN MAX OSC
(
V
(
TARGET
is the differential current-
IN MAX
TARGET
is the differential current-
(
⎞
⎟ −
⎠
−
(
R
R
FBAC FBAC
+
)
SENSE m FBDC
is 1.03mS (max), as
)
)
V
is typically 1mS as
Δ
f
V
FBDC
FBAC
)
I R
m(FBDC)
FBDC
L ESR
) is defined in the
) is defined in the
−
I
V
L
OUT MIN
G
) is determined
) is determined
to zero.
≤18
(
(
ESR
is 1.03mS
mV
SENSE
)
)
)
is the
is