LTC3634EUFD Demo Board (QFN) | VIN= 3.6V to 15V, VOUT1 =1.5V/1.8V/2.5V@±3A, VOUT2 = 0.5VIN (VTT)@±3A, VOUT3 = 0.5VIN (VTTR)@±10mA
LTC3634EUFD Demo Board (QFN) | VIN= 3.6V to 15V, VOUT1 =1.5V/1.8V/2.5V@±3A, VOUT2 = 0.5VIN (VTT)@±3A, VOUT3 = 0.5VIN (VTTR)@±10mA
Product Detail
Demonstration circuit DC1708A is a dual-output regulator
focused specifically for DDR memory power applications.
It is built based on the LTC3634, a high voltage dualchannel,
controlled on-time monolithic synchronous buck
regulator. The DC1708A has an input voltage range of 3.6V
to 15V. The output voltage of the first channel, VDDQ, of
the DC1708A has three fixed voltage settings: 1.5V, 1.8V
and 2.5V, and is capable of delivering up to 3A of output
current. The second channel, VTT, is set to regulate to half
the voltage on the VDDQIN pin, which can be either the
channel 1 output or an external reference voltage. It can
source or sink a maximum of 3A of output current. The
LTC3634 also provides a 10mA buffered output of half
VDDQIN – VTTR, which is used to provide the reference
voltage needed for DDR applications. With the use of a
timing resistor, the DC1708A can have its operating frequency
programmed from 500kHz to 4MHz. Additionally
the DC1708A can be easily synchronized to an external
clock, due to an internal phase-locked loop, within this
same frequency range. The DC1708A VDDQ output can operate in either Burst Mode® operation or forced continuous
mode. In Burst Mode operation, which is the preferred
mode of low load current operation, the DC supply current
is typically only 1.3mA (both channels) at no load (sleep
mode), and less than 15µA in shutdown. In Burst Mode
operation or continuous mode operation, the DC1708A
is a very efficient circuit at high load currents: over 80%
for either channel. The LTC3634 is also capable of 90° or
180° out-of-phase operation, and can allow its output to
track an external voltage, either coincidentally or ratiometrically.
The LTC3634 comes in a 28-pin QFN package,
featuring an exposed pad on the bottom-side of the IC for
better thermal performance. All of these features make
the DC1708A an ideal circuit for powering DDR memory
applications.