DEMO MANUAL DC2367A
LTM4632EV
Ultrathin µModule Regulator for DDR-QDR4
Memory VDDQ, VTT and VREF
DESCRIPTION
Demonstration circuit DC2367A features the
LTM
®
4632EV
µModule
®
regulator, a tiny low-profile high-performance
high efficiency dual step-down regulator for DDR power.
LTM4632 has an operating input voltage range of 3.6V
to 15V. The output voltage of channel 1 (VDDQ) is resis-
tor programmable from 0.6V to 2.5V and is capable of
delivering up to 3A of output current. The output voltage
of channel 2 (VTT) is set to regulate ½ of the voltage on
the VDDQIN pin which can provided by either the channel
1 output or an external reference voltage. It can source or
sink up to 3A of output current. A 10mA buffered output
of VDDQIN/2 is also provided for supplying VREF voltage
for DDR memory. DC2367A also provides the option for
paralleling channels 1 and 2 together for up to 6A capable
VTT rail. LTM4632 is a complete DC/DC DDR dual point
of load regulator in a low-profile thermally enhanced
6.25mm × 6.25mm × 1.82mm LGA package requiring
only a few input and output capacitors. Output voltage
tracking is available through the TRACK/SS pin for supply
rail sequencing. External clock synchronization is avail-
able through the SYNC/MODE pin. For high efficiency at
low load currents the MODE pin jumper (JP4) selects the
Burst Mode
®
option for operation in less noise sensitive
applications. The LTM4632 data sheet must be read in
conjunction with this demo manual for working on or
modifying demo circuit 2367A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2367A
L,
LT, LTC, LTM, Linear Technology, the Linear logo, µModule and Burst Mode are registered
trademarks of Linear Technology Corporation. All other trademarks are the property of their
respective owners.
BOARD PHOTO
dc2367af
1
DEMO MANUAL DC2367A
PERFORMANCE SUMMARY
PARAMETER
Input Voltage Range
Output Voltage V
OUT1
(VDDQ)
Maximum Continuous Output Current I
OUT1
Output Voltage V
OUT2
(VTT)
Maximum Continuous Output Current I
OUT2
Default Operating Frequency
Efficiency
V
IN
= 12V, V
OUT1
= 2.5V, I
OUT
= 3A, f
SW
= 1MHz
V
IN
= 12V, V
OUT2
= 1.25V, I
OUT
= 3A, f
SW
= 1MHz
Resistor Programmable, Jumper Selectable
CONDITIONS
Specifications are at T
A
= 25°C
MIN
3.6
1.5 (±1.5%)
1.8 (±1.5%)
2.5 (±1.5%)
3
0.75
0.9
1.25
±3
1
83.9
(See Figure 2)
72.3
(See Figure 3)
TYP
MAX
15
UNITS
V
V
V
V
A
V
V
V
A
MHz
%
%
Derating Is Necessary for Certain Operating
Conditions. See Data Sheet for Details
V
OUT1
= 1.5V
V
OUT1
= 1.8V
V
OUT1
= 2.5V
Derating Is Necessary for Certain Operating
Conditions. See Data Sheet for Details
QUICK START PROCEDURE
Demonstration circuit DC2367A is an easy way to evaluate
the performance of the LTM4632. Please refer to Figure 1
for test setup connections and follow the procedure below.
1. With power off, place the jumpers in the following
positions for a typical application for 2.5V
OUT1
and
1.25V
OUT2
rails:
JP1
RUN1
ON
JP2
RUN2
ON
JP3
TRACK/SS
SS
JP4
MODE
CCM
JP6
VDDQ SEL
2.5V
3. With power off, connect the loads, input voltage supply
and meters as shown in Figure 1.
4. Turn on the input power supply. The output voltage me-
ters for each output rail should display the programmed
output voltage ±1.5%.
5. Once the proper output voltages are established, ad-
just the load current on each rail within the 0A to 3A
range and observe each output rail’s load regulation,
efficiency, and other parameters.
6. To observe increased light load efficiency place the
mode pin jumper (JP4) in the BURST MODE position.
2. Before powering up the input supply and loads, preset
the input voltage supply to be between 3.6V to 15V.
Preset the load current for each output rail to 0A.
dc2367af
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