Linear Technology DC2249A Demo Manual

DESCRIPTION
Demonstration Circuit 2249A features the
μModule regulator, a tiny low profile high performance
®
high efficiency dual step-down regulator. The LTM4622
has an operating input voltage range of 3.6V to 20V and
is able to provide an output current of up to 2.5A for each
channel. Each output's voltage is programmable from 0.6V
to 5.5V. The LTM4622 is a complete DC-DC 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.
PERFORMANCE SUMMARY
PARAMETER
Input Voltage Range
Output Voltage V , V
OUT1
Maximum Continuous Output Current Each Phase
Default Operating Frequency
Efficiency
BOARD PHOTO
Arrow.com.
Downloaded from
LTM
CONDITIONS/NOTES
Programmable with FB Pin Resistors
OUT2
Derating is Necessary for Certain Operating
Conditions. See Data Sheet for Details
V
IN
V
IN
DEMO MANUAL DC2249A
Ultrathin Dual 2.5A, Single 5A
Step-Down μModule Regulator
4622EV External clock synchronization is available through the
®
SYNC/MODE pin. For high efficiency, at low load currents,
the MODE pin jumper (JP3) selects the Burst Mode
tion for operation in less noise sensitive applications. The
LTM4622 data sheet must be read in conjunction with
this demo manual for working on or modifying DC2249A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2249A
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.
Specifications are at T = 25°C
A
= 12V, V = 3.3V, I = 2.5A, f
OUT1 OUT
= 12V, V = 1.2V, I = 2.5A, f
OUT2 OUT
LTM4622EV
VALUE
4V – 20V
3.3VDC, 1.2VDC
2.5ADC
1MHz
= 2MHz 87.5%, See Figure 2
SW
= 1MHz 76.7%, See Figure 2
SW
op-
®
dc2249afa
1