Linear Technology DC1780A-C Demo Manual page 2

DEMO MANUAL DC1780A-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
Output Voltage Ripple
QUICK START PROCEDURE
Table 1. LTM4620 Demo Cards for up to 100A Point-of-Load Regulation
MAXIMUM
OUTPUT CURRENT
13A, 13A
50A
75A
100A
Demonstration circuit DC1780A-C is easy to set up to
evaluate the performance of PolyPhase operation of the
LTM4620EV. Due to the high input/output current, select
a proper input supply/load/cable which can sustain the
full load operation. 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 JP2
CLK RUN
INT_CLK OFF
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
2
Specifications are at T
CONDITIONS/NOTES
V = 4.5V to 16V, I = 0A to 100A, JP4: 1.0V
IN OUT
Derating is necessary for certain V
conditions, see data sheet for detail.
V = 12V, V = 1.0V, I = 100A, f
IN OUT OUT
V = 12V, V = 1.0V, I = 50A to 100A
IN OUT SETP
V = 12V, V = 1.0V, I = 100A, f
IN OUT OUT
NUMBER OF OUTPUT
VOLTAGES
2
1
1
1
JP4-JP8
V SELECT
OUT
ON JP4/1.0V
= 25°C
A
, V and thermal
IN OUT
= 500kHz
SW
= 500kHz
SW
NUMBER OF LTM4620 μMODULE
REGULATORS ON THE BOARD
1
2
3
4
3. Turn on the power supply at the input. Place JP2 to
ON position. The output voltage between V
–
V should be 1.0V ± 1.5% (0.985V to 1.015V).
OUT
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 voltage ripple should
be measured at J7 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. The pulse amplitude (3V to 3.5V) sets the load
step current amplitude. The output transient current can
be monitored at the BNC connector J8 (5mV/A). The
pulse signal should be very small duty cycle (< 10%)
to limit the thermal stress on the transient load circuit.
VALUE
4.5V to 16V
1.0V ± 1.5% (0.985V to 1.015V)
100A
500kHz
400kHz to 780kHz
400kHz to 780kHz
80.5% See Figure 4
<156mV, See Figure 5
<10mV, See Figure 6
DEMO CARD NUMBER
DC1498A
DC1780A-A
DC1780A-B
DC1780A-C
OUT
+
and
dc1780acfa