Performance Summary; Quick Start Procedure - Linear Technology DC2455A-C Demo Manual

DEMO MANUAL DC2455A-C

performance summary

PARAMETER
Input Voltage Range
Output Voltage V
OUT
Maximum Continuous Output Current
Default Operating Frequency
Resistor Programmable Frequency Range
External Clock Sync. Frequency Range
Efficiency
Load Transient

Quick start proceDure

Demonstration circuit DC2455A-C is easy to set up to
evaluate the performance of PolyPhase operation of the
LTM4650EY-1. Due to the high input/output current, user
should select the proper input supply/load/cable which
can sustain the full load operation. It's recommended to
pull load current from J2 and J4. The load current pulled
from J5 and J6 shouldn't exceed 25A. Please refer to
Figure 2 for proper measurement setup and follow the
procedure below:
1. Place jumpers in the following positions for a typical
1.0V application:
OUT
JP1
CLK
INT
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. Place JP2 to ON
position. The output voltage between "V
should be 1.0V ± 1.5% (0.985V~1.015V).
4. Once the proper output voltage is established, adjust the
load within the operating range and observe the output
2
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Specifications are at T
CONDITIONS / NOTES
V = 4.5V to 15V, I
IN
De-rating is necessary for certain V
conditions, see data sheet for detail.
V = 12V, V
IN OUT
V = 12V, V
IN OUT
JP2 JP4~JP8
RUN V SELECT
OUT
OFF ON JP5 / 1.0V
+
" and "V
O
= 25°C
A
= 0A to 200A, JP5: 1.0V
OUT
, V and thermal
IN OUT
= 1.0V, I = 200A, f = 500kHz
OUT SW
= 1.0V, I = 100A to 150A
STEP
voltage regulation, output voltage ripple, efficiency
and other parameters. Output voltage ripple should be
measured at J11 with BNC cables. 50Ω termination
should be set on the oscilloscope or BNC cables.
5. (Optional) For optional load transient test, apply an
adjustable pulse signal between "IOSTEP CLK" and
"GND" test point. Pulse amplitude (3V~3.5V) sets the
load step current amplitude. The output transient current
can be monitored at the BNC connector J12 (5mV/A).
The pulse signal should be very small duty cycle (<10%)
to limit the thermal stress on the transient load circuit.
6. (Optional) LTM4650-1 can be synchronized to an
external clock signal. Place the JP1 jumper on EXT
and apply a clock signal (0V~5V, square wave) on the
"EXT_CLK" test point.
7. (Optional) The outputs of LTM4650-1 can track another
supply. The output voltage tracks the voltage on TRACK
when a valid signal is applied on the test point.
8. (Optional) DC2455A-C can be configured to a dual
outputs configuration with V
–
"
O
and V at 25A load current. Stuff 0Ω resistor on R61
O2
and 0.1µF on C14. Remove R22, R23, R24, R26, R27,
R28, R32, R33, R35. Output voltage V
based on the equation V
VALUE
4.5V ~ 15V
1.0V ± 1.5% (0.985V ~ 1.015V)
200A
500kHz
400kHz – 780kHz
400kHz – 780kHz
86.1% See Figure 3
< 53mV, See Figure 4
at 175A load current
O
is set by R37
O2
= 0.6V(1+60.4k /R37).
O2
dc2455acf