MAX15112EVKIT# Maxim Integrated, MAX15112EVKIT# Datasheet - Page 12

• Manufacturer Part Number: MAX15112EVKIT#
• Description: Power Management IC Development Tools MAX15112 Eval Kit
• Manufacturer: Maxim Integrated
• Type: Power Switchesr
• Series: MAX15112r

Specifications of MAX15112EVKIT#

• Rohs: yes
• Product: Evaluation Kits
• Tool Is For Evaluation Of: MAX15112
• Input Voltage: 2.7 V to 5.5 V
• Output Voltage: 0.6 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Output Current: 12 A
• For Use With: MAX15112

The MAX15112 high-efficiency, current-mode switching
regulator delivers up to 12A of output current. The regu-
lator provides output voltages from 0.6V up to 0.94 x V
from 2.7V to 5.5V input supplies, making the device ideal
for on-board point-of-load applications.
The MAX15112 delivers current-mode control architec-
ture using a high-gain transconductance error amplifier.
The current-mode control architecture facilitates easy
compensation design and ensures cycle-by-cycle cur-
rent limit with fast response to line and load transients.
The regulator features a 1MHz fixed switching frequen cy,
allowing for all-ceramic capacitor designs and fast tran-
sient responses. The high operating frequency mini mizes
the size of external components.
The regulator offers a selectable skip mode functional ity
to reduce current consumption and achieve a higher
efficiency at light output loads. Integrat ed switches
ensure high efficiency at heavy loads while minimizing
critical inductances.
The MAX15112 features PWM current-mode control,
allowing for an all-ceramic capacitor solution. The regu-
lator offers capacitor-programmable soft-start to reduce
input inrush current. The device safely starts up into a
prebiased output. The MAX15112 includes an enable
input and open-drain PGOOD output for sequencing with
other devices.
The controller logic block is the central processor that
determines the duty cycle of the high-side MOSFET
under different line, load, and temperature conditions.
Under normal operation, where the current-limit and
temperature protection are not triggered, the controller
logic block takes the output from the PWM comparator
and generates the driver signals for both high-side and
low-side MOSFETs. The control logic block controls the
break-before-make logic and all the necessary timing.
The high-side MOSFET turns on at the beginning of the
oscillator cycle and turns off when the COMP volt age
crosses the internal current-mode ramp waveform. The
internal ramp is the sum of the compensation ramp and
the current-mode ramp derived from the inductor current
(current-sense block). The high-side MOSFET also turns
off if either the maximum duty cycle (94%, typ) or the cur-
rent limit is reached. The low-side MOSFET turns on for
the remain der of the oscillation cycle.
High-Efficiency, 12A, Current-Mode Synchronous
Step-Down Regulator with Integrated Switches
Controller Function—PWM Logic
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Detailed Description
IN
The MAX15112 can soft-start into a prebiased output
without discharging the output capacitor. In safe pre-
biased startup, both low-side and high-side MOSFETs
remain off to avoid discharging the prebiased output.
PWM operation starts when the voltage on SS/REFIN
crosses the voltage on FB.
The MAX15112 can start into a prebiased voltage higher
than the nominal set point without abruptly discharg-
ing the output. Forced PWM operation starts when the
SS/REFIN voltage reaches 0.58V (typ), forcing the con-
verter to start. The low-side current limit is increased over
350µs to the maximum from the first LX pulse. When the
low-side sink current-limit threshold of 18A is reached,
the low-side switch turns off before the end of the clock
period and the high-side switch turns on until one of the
following conditions is satisfied:
U High-side source current hits the reduced high-side
U The clock period ends.
Reduced high-side current limit is activated to recirculate
the current into the high-side power switch rather than
into the internal high-side body diode.
Low-side sink current limit is provided to protect the
low-side switch from excessive reverse current dur ing
prebiased operation.
The MAX15112 features independent enable control and a
power-good signal that allows for flexible power sequenc-
ing. Drive the enable input (EN) high to enable the regula-
tor, or connect EN to IN for always-on operation.
Power good (PGOOD) is an open-drain output that
asserts when V
low if V
The MAX15112 utilizes a soft-start feature to slowly
ramp up the regulated output voltage to reduce input
inrush current during startup. Connect a capacitor from
SS/REFIN to GND to set the startup time (see the
the Soft-Start Time
current limit (18A, typ); in this case, the high-side
switch is turned off for the remaining time of the clock
period.
FB
Programmable Soft-Start (SS/REFIN)
is below 529mV (typ).
Starting into a Prebiased Output
FB
section for capacitor selection details).
Enable Input and Power-Good
is above 554mV (typ) and deasserts
MAX15112
(PGOOD) Output
Setting