The MAX8632 integrates a synchronous-buck PWM controller
to generate VDDQ, a sourcing and sinking LDO linear
regulator to generate VTT, and a 10mA reference
output buffer to generate VTTR. The buck controller drives
two external n-channel MOSFETs to generate output voltages
down to 0.7V from a 2V to 28V input with output currents
up to 15A. The LDO can sink or source up to 1.5A
continuous and 3A peak current. Both the LDO output
and the 10mA reference buffer output can be made to
track the REFIN voltage. These features make the
MAX8632 ideally suited for DDR memory applications in
desktops, notebooks, and graphic cards.
The PWM controller in the MAX8632 utilizes Maxim's
proprietary Quick-PWM™ architecture with programmable
switching frequencies of up to 600kHz. This control
scheme handles wide input/output voltage ratios with
ease and provides 100ns response to load transients
while maintaining high efficiency and a relatively constant
switching frequency. The MAX8632 offers fully programmable
UVP/OVP and skip-mode options ideal in
portable applications. Skip mode allows for improved
efficiency at lighter loads.
The VTT and VTTR outputs track to within 1% of VREFIN / 2.
The high bandwidth of this LDO regulator allows excellent
transient response without the need for bulk capacitors,
thus reducing cost and size.
The buck controller and LDO regulators are provided with
independent current limits. Adjustable lossless foldback
current limit for the buck regulator is achieved by monitoring
the drain-to-source voltage drop of the low-side
MOSFET. Additionally, overvoltage and undervoltage protection
mechanisms are built in. Once the overcurrent
condition is removed, the regulator is allowed to enter
soft-start again. This helps minimize power dissipation
during a short-circuit condition. The MAX8632 allows flexible
sequencing and standby power management using
the SHDN-bar and STBY-bar inputs, which support all DDR
operating states.
The MAX8632 is available in a small 5mm x 5mm, 28-pin thin QFN package.
Key Features
Applications/Uses
Buck Controller
Quick-PWM with 100ns Load-Step Response
Up to 95% Efficiency
2V to 28V Input Voltage Range
1.8V/2.5V Fixed or 0.7V to 5.5V Adjustable Output
Up to 600kHz Selectable Switching Frequency
Programmable Current Limit with Foldback
Capability
* 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
MAX8632
Free Sample
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Package:
TYPE PINS FOOTPRINT
DRAWING CODE/VAR *
Temp
RoHS/Lead-Free? Materials Analysis
MAX8632ETI+
THIN QFN;28 pin;
Dwg: 21-0140 (PDF)
Use pkgcode/variation: T2855+6*
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