The MAX8643A high-efficiency switching regulator
delivers up to 3A load current at output voltages from
0.6V to (0.9 x VIN).The IC operates from 2.35V to 3.6V,
making it ideal for on-board point-of-load and postregulation
applications. Total output error is less than ±1%
over load, line, and temperature.
The MAX8643A features fixed-frequency PWM mode
operation with a switching frequency range of 500kHz
to 2MHz set by an external resistor. High-frequency
operation allows for an all-ceramic capacitor design.
The high operating frequency also allows for small-size
external components.
The low-resistance on-chip nMOS switches ensure high
efficiency at heavy loads while minimizing critical inductances,
making the layout a much simpler task with
respect to discrete solutions. Following a simple layout
and footprint ensures first-pass success in new designs.
The MAX8643A comes with a high-bandwidth (> 14MHz)
voltage-error amplifier. The voltage-mode control architecture
and the voltage-error amplifier permit a type III
compensation scheme to be utilized to achieve maximum
loop bandwidth, up to 20% of the switching frequency.
High loop bandwidth provides fast transient
response, resulting in less required output capacitance
and allowing for all-ceramic capacitor designs.
The MAX8643A provides two tri-state logic inputs to
select one of nine preset output voltages. The preset
output voltages allow customers to achieve ±1% output-voltage accuracy without using expensive 0.1% resistors. In addition, the output voltage can be set to any customer value by either using two external resistors
at the feedback with 0.6V internal reference or
applying an external reference voltage to the REFIN
input. The MAX8643A offers programmable soft-start
time using one capacitor to reduce input inrush current.
The MAX8643A is available in a lead-free, 24-pin, 4mm x 4mm thin QFN package.
Key Features
Applications/Uses
Internal 37mΩ RDSON MOSFETs
Continuous 3A Output Current
±1% Output Accuracy Over Load, Line, and Temperature
Operates from 2.35V to 3.6V Supply
Adjustable Output from 0.6V to (0.9 x VIN)
Soft-Start Reduces Inrush Supply Current
500kHz to 2MHz Adjustable Switching Frequency
Compatible with Ceramic, Polymer, and Electrolytic Output Capacitors
VID-Selectable Output Voltages
0.6, 0.7, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, and 2.5V
Fully Protected Against Overcurrent and Overtemperature
* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.
Devices:
1-2
of
2
MAX8643A
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Package:
TYPE PINS FOOTPRINT
DRAWING CODE/VAR *
Temp
RoHS/Lead-Free? Materials Analysis
MAX8643AETG+
THIN QFN;24 pin;17 mm²
Dwg: 21-0139H (PDF)
Use pkgcode/variation: T2444+4*
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