MAX15039_11 Datasheet, PDF (11/19 Pages) Maxim Integrated Products – 6A, 2MHz Step-Down Regulator with Integrated Switches Open-Drain, Power-Good Output

6A, 2MHz Step-Down Regulator
with Integrated Switches
INPUT
2.9V TO 5.5V
C6
C7
22μF
0.1μF
C5
2.2μF
R4
49.9kΩ
IN
BST
MAX15039
LX
V_DD
OUT
CTL2
CTL1
EN
FREQ
REFIN
SS
C4
0.022μF
PGND
FB
COMP
MODE
PWRGD
GND
2.2Ω
C10
0.1μF
L1
0.47μH
OPTIONAL
C15
1000pF
OUTPUT
1.8V, 6A
C3
560pF
R3
158Ω
C8
C9
22μF
0.01μF
C2
1500pF
R2
2.67kΩ
C1
33pF
V_DD
R1
20kΩ
Figure 1. Typical Application Circuit: 1MHz, All-Ceramic-Capacitor Design with V_IN = 2.9V to 5.5V and V_OUT = 1.8V
Detailed Description
The MAX15039 high-efficiency, voltage-mode switching
regulator delivers up to 6A of output current. The
MAX15039 provides output voltages from 0.6V to 0.9 x
V_IN from 2.9V to 5.5V input supplies, making it ideal for
on-board point-of-load applications. The output-voltage
accuracy is better than ±1% over load, line, and tem-
perature.
The MAX15039 features a wide switching frequency
range, allowing the user to achieve all-ceramic-capaci-
tor designs and fast transient responses (see Figure 1).
The high operating frequency minimizes the size of
external components. The MAX15039 is available in a
small (4mm x 4mm), lead-free, 24-pin thin QFN pack-
age. The REFIN function makes the MAX15039 an ideal
candidate for DDR and tracking power supplies. Using
internal low-R_DS(ON) (20mΩ for the low-side n-channel
MOSFET and 26mΩ for the high-side n-channel
MOSFET) maintains high efficiency at both heavy-load
and high-switching frequencies.
The MAX15039 employs voltage-mode control architec-
ture with a high bandwidth (28MHz) error amplifier. The
voltage-mode control architecture allows up to 2MHz
switching frequency, reducing board area. The op amp
voltage-error amplifier works with type III compensation
to fully utilize the bandwidth of the high-frequency
switching to obtain fast transient response. Adjustable
soft-start time provides flexibilities to minimize input
startup inrush current. An open-drain, power-good
(PWRGD) output goes high when V_FB reaches 92.5% of
V_REFIN and V_REFIN is greater than 0.54V.
The MAX15039 provides an option for three modes of
operation: regular PWM, PWM mode with monotonic
startup into prebiased output, or skip mode with monot-
onic startup into prebiased output.
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