19-4504; Rev 4; 6/11
1.8A Step-Down Regulator with
Remote Sense in 2mm x 2mm WLP
The MAX8649/MAX8649A high-efficiency DC-to-DC step-
down switching regulators deliver up to 1.8A of output cur-
rent. The device operates from a 2.5V to 5.5V input
voltage range, making it future proof for next-generation
battery technologies. The output voltage is I2C program-
mable from 0.75V to 1.38V. Remote sense ensures pre-
cise DC regulation at the load. Total output error is less
than 2% over load, line, and temperature.
The ICs operate at a 3.25MHz fixed frequency. The high
operating frequency minimizes the size of external com-
ponents. The switching frequency of the converter can be
synchronized to the master clock of the application. When
synchronizing to an external clock, the ICs measure the
frequency of the external clock to ensure that the clock is
stable before changing the switching frequency to the
external clock frequency.
An on-board DAC allows adjustment of the output volt-
age in 10mV steps. The output voltage can be pro-
grammed directly through the I2C interface, or by
preloading a set of on-board registers and using the
two VID logic signals to select the appropriate register.
Other features include internal soft-start control circuitry
to reduce inrush current, output overvoltage, overcur-
rent, and overtemperature protection.
The ICs feature different I2C addresses so that devices
may be used in a system. For a 2.5A version of this
device, refer to the MAX8952 data sheet.
Cell Phones and Smartphones
PDAs and MP3 Players
(BUMPS ON BOTTOM)
o 1.8A Guaranteed Output Current
o I2C Programmable VOUT (750mV to 1.38V in 10mV
o Operates from 2.5V to 5.5V Input Supply
o On-Chip FET and Synchronous Rectifier
o Fixed 3.25MHz PWM Switching Frequency
o Synchronizes to 13MHz, 19.2MHz, or 26MHz
System Clock when Available
o Small 1.0µH Inductor
o Initial Accuracy 0.5% at 1.25V Output
o 2% Output Accuracy Over Load, Line, and
o Power-Save Mode Increases Light Load Efficiency
o Overvoltage and Overcurrent Protection
o Thermal Shutdown Protection
o 400kHz I2C Interface
o < 1µA Shutdown Current
o 16-Bump, 2mm x 2mm WLP Package
MAX8649EWE+T 16 WLP (0.5mm pitch)
MAX8649AEWE+T 16 WLP (0.5mm pitch)
+Denotes a lead(Pb)-free/RoHS-compliant package.
Note: All devices operate over the -40°C to +85°C temperature
Typical Operating Circuit
WLP 0.5mm PITCH
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.