EVALUATION KIT AVAILABLE
MAX77756
24V Input, 500mA Buck Regulator
with Dual-Input Power MUX
General Description
Benefits and Features
The MAX77756 is a synchronous 500mA step-down
DC-DC converter with integrated dual-input power multi-
plexer (MUX). The converter operates on an input supply
as low as 3.0V and as high as 24V. Default output volt-
age is factory-programmed to either 1.8V, 3.3V, or 5.0V.
Output voltage is further adjustable through external
● Wide Input Power Supply
• 3V to 24V Supply Voltage
• 500mA (max) Output Current
• 1.8V, 3.3V, or 5.0V Factory-Set V
2
with
OUT
Optional I C Control: 1.5V to 7.5V in 50mV Steps
• External Feedback Resistor V
Option (1V to
OUT
2
resistors or an I C serial interface.
99% V
)
SUP
• Hardware or Software Enable
The dual-input power MUX selects the higher voltage
from two different input sources to power the step-down
converter. Control circuitry ensures that only one channel
of the MUX is on at a time to prevent cross-conduction
between input sources. For single-input applications, the
MUX can be bypassed and the step-down converter can
be powered directly from the SUP pin.
● Dual-Input Power MUX Replaces Common-Cathode
Diode Arrays
• Automatic Ideal-Diode ORing Voltage Selector
• 250mΩ MOSFETs Minimize Power Consumption,
BOM, and Solution Size
● Low I Enables Always-On Rails
Q
The MAX77756 is available in a small 2.33mm x 1.42mm
(0.7mm max height), 15-bump wafer-level package
(WLP). For a similar buck converter without a power
MUX, refer to the MAX77596.
• 1.5μA Quiescent Current (Only SUP Powered)
• 19μA Quiescent Current (IN1/IN2 Powered)
• 88% Peak Efficiency (12V
, 3.3V
)
SUP
OUT
● Safe and Easy to Use
• Short-Circuit Hiccup Mode and Thermal Protection
• 8ms Soft-Start
• Software-Enabled Spread Spectrum
• Pin-Programmable Inductor Peak Current Level
Applications
● USB Type-C Power Delivery Accessories and
Devices
● Notebook and Tablet Computers
● Home Automation, Low I Smart Hubs
● Battery-Powered Systems, Backup Battery,
Uninterruptible Rails
Ordering Information appears at end of data sheet.
● Small Size
Q
• 2.33mm x 1.42mm (0.7mm max height)
Wafer-Level Package (WLP)
• 15-Bump, 0.4mm Pitch, 3 x 5 Array
Simplified Block Diagram
POWER MUX
3V TO 24V DC SOURCE 1
IN1
- MAIN BATTERY
- USB PD PROVIDER
SUP
BST
IDEAL
IN2
3V TO 24V DC SOURCE 2
- BACKUP BATTERY
- SOLAR CELL ARRAY
10µH
LX
V
IO
V
OUT
BUCK
1.5V TO 7.5V
1.8V, 3.3V, 5.0V DEFAULTS
500mA MAX
SDA
SCL
EN
CONVERTER
HARDWARE OR
SOFTWARE
ENABLE
OUT/ FB
POK
DIGITAL
CONTROL
POWER OK
PGND
AGND, ILIM, BIAS
PINS NOT DRAWN
24V, 500mA DC-DC BUCK CONVERTER WITH IDEAL-DIODE “ORING” MUX
19-8710; Rev 1; 10/17