2
dc2268abfa
DEMO MANUAL DC2268A-B
Quick start proceDure
Demonstration circuit DC2268A-B is easy to set up to
evaluate the performance of the LTM4620A. It can be
easily inserted to an edge connector (SAMTEC MEC2-
20-01-L-DV--TR) for testing and debugging. Please refer
to Figure 2 for proper measurement setup and follow the
procedure below:
1. Pull up the RUN1 (J1 pin 22) and RUN2 (J1 pin 24)
between 1.4V to 5V or leave them floating.
2. With power off, connect the input power supply, load
and meters as shown in Figure 1. Preset the load to 0A
and V
IN
supply to 12V.
3. Turn on the power supply at the input. The output volt-
age in channel 1 should be 3.3V ± 1.5% (3.2505V ~
3.3495V) and the output voltage in channel 2 should
be 5V ± 1.5% (4.925V ~ 5.075V),
4. Once the proper output voltage is established, adjust the
load within the operating range and observe the output
voltage regulation, output voltage ripple, efficiency and
other parameters. Output ripple should be measured
at Co3 and Co4.
5. (Optional) LTM4620A can be synchronized to an exter-
nal clock signal. Remove R2 and apply a clock signal
(0~5V, square wave) to MODE-PLLIN pin.
6. (Optional) LTM4620A can be configured for a 2-phase
single output at up to 36A on DC2268A-B. Install 0Ω
resistors on R26, R27, R28, R29, R32, and remove
R14, R18, R30. Output voltage is set by R7 based on
equation V
OUT
= 0.6V(1 + 60.4k/R7).
PARAMETER
CONDITIONS
VALUE
Input Voltage Range
5.5V ~ 16V
Output Voltage V
OUT1
V
IN
= 4.5V ~ 15V, I
OUT1
= 0A ~ 13A
3.3V ±1.5%
Output Voltage V
OUT2
V
IN
= 4.5V ~ 15V, I
OUT2
= 0A ~ 13A
1.5V ±1.5%
Per-Channel Maximum Continuous Output Current
Derating Is Necessary for Certain V
IN
, V
OUT
and Thermal
Conditions.
13A
Default Operating Frequency
750kHz
Resistor Programmable Frequency Range
250kHz to 780kHz
External Clock Sync. Frequency Range
400kHz to 780kHz
Efficiency of Channel 1
V
IN
= 12V, V
OUT2
= 3.3V, I
OUT2
= 13A, f
SW
= 750kHz
91.8% See Figure 3
Efficiency of Channel 2
V
IN
= 12V, V
OUT1
= 5V, I
OUT1
= 13A, f
SW
= 750kHz
93.9% See Figure 4
Load Transient of Channel 1
V
IN
= 12V, V
OUT2
= 3.3V, I
STEP
= 6.5A ~ 13A
See Figure 5
Load Transient of Channel 2
V
IN
= 12V, V
OUT1
= 5V, I
STEP
= 6.5A ~ 13A
See Figure 6
performance summary
Specifications are at T
A
= 25°C
