Linear Technology DC2268A-1 Demo Manual page 2

DEMO MANUAL DC2268A-I
PERFORMANCE SUMMARY
Table 1.
PARAMETER
Input Voltage Range
Output Voltage V
OUT1
Output Voltage V
OUT2
Per-Channel Maximum Continuous Output Current
Default Operating Frequency
External Clock Sync. Frequency Range
Efficiency of Channel 1
Efficiency of Channel 2
Load Transient of Channel 1
Load Transient of Channel 2
QUICK START PROCEDURE
DC2268A-I is easy to set up to evaluate the performance
of the LTM4650A-1. 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 mea-
surement 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 2. Preset the load to 0A
and V supply to 12V.
IN
3. Turn on the power supply at the input. The output
voltage in channel 1 should be 3.3V ± 1.5% (3.25V ~
3.35V) and the output voltage in channel 2 should be
1.5V ± 1.5% (1.478V ~ 1.523V),
Table 2. DC2268A Demo Circuit
DEMO BOARD NUMBER
DC2268A-A
DC2268A-B
DC2268A-C
DC2268A-D
DC2268A-E
DC2268A-F
DC2268A-G
DC2268A-H
DC2268A-I
2
Specifications are at T
CONDITIONS
V = 4.5~16V, I = 0A ~25A
IN OUT1
V = 4.5~16V, I = 0A ~25A
IN OUT2
De-rating is necessary for certain V
V = 12V, V = 3.3V, I
IN OUT1 OUT1
V = 12V, V = 1.5V, I
IN OUT2 OUT2
V = 12V, V = 3.3V, I
IN OUT1 STEP
V = 12V, V = 1.5V, I
IN OUT2 STEP
4. Once the proper output voltage is established, adjust
5. (Optional) LTM4650A-1 can be synchronized to an
6. (Optional) LTM4650A-1 can be configured for a 2-phase
µModule REGULATOR ON THE BOARD
LTM4620
LTM4620A
LTM4628
LTM4630
LTM4630-1
LTM4630A
LTM4631
LTM4650-1
LTM4650A-1
= 25°C
A
, V and thermal conditions
IN OUT
= 25A, f = 600kHz
SW
= 25A, f = 600kHz
SW
= 12.5A ~ 18.75A
= 12.5A ~ 18.75A
NOTE: Due to very small PCB size of the DC2268A
board, the LTM43650A-1 module can be quite hot at
heavy load. Cooling air is required. See Figures 7 and 8
the load within the operating range and observe the
output voltage regulation, output voltage ripple, effi-
ciency and other parameters. Output ripple should be
measured at C and C
o3 o4
external clock signal. Remove R2 and apply a clock
signal (0V~5V, square wave) to MODE-PLLIN pin.
single output at up to 36A on DC2268A-I. Install 0Ω
resistors on R26, R27, R28, R29, R32, and remove
R14, R18 R30. Output voltage is set by R7 based on
equation V = 0.6V (1 + 60.4k/R7).
OUT
OUTPUT CURRENT
13A,13A
13A,13A
8A, 8A
18A,18A
18A,18A
18A, 18A
10A, 10A
25A, 25A
25A, 25A
VALUE
4.5V ~ 16V
3.3V ± 1.5%
1.5V ± 1.5%
25A (per channel)
600kHz
400kHz to 780kHz
94.4%, see Figure 3
90.0%, see Figure 4
V = 157mV, see Figure 5
OPP
V = 127mV, see Figure 6
OPP
.
dc2268aif