Quick Start Procedure - Analog Devices DC3205A Demo Manual

QUICK START PROCEDURE

Refer to Figure 2 for the proper measurement equipment
setup and follow the procedure below:
NOTE: For accurate V , V
IN
ments, measure V at the VIN SNSE and GND SNSN tur-
IN
rets, and measure V at the VOUT SNSE and GND SNSE
OUT
turrets. When measuring the input or output ripple, care
must be taken to avoid a long ground lead on the oscillo-
scope probe. It is recommended to use technique shown
in Figure 3 and Figure 4 for basic ripple measurement.
Prepare for the Test
A. Select a power supply PS1 that can handle 5V of out-
put voltage and 10A of output current, with internal
current meter. If possible, connect PS1 Kelvin Sense
terminals with VIN SNSE and GND SNSE turrets.
B. Select an electronic load LD1 can handle 1.5V of load
voltage and up to 8A of load current in constant cur-
rent mode.
C. Select an oscilloscope with two or more channels and
two voltage probes.
1. Connect PS1, LD1, VM1, VM2 and VM3 as shown in
Figure 2. If the input EMI filter is desired, connect the
input power supply to VIN EMI and GND.
2. Set the JP2 to HI position. Set LD1 to 0A. Slowly
increase PS1 to 1V. If PS1 current reads less than
20mA, increase PS1 to 3.3V until VM1 reads 3.3V
±10mV. VM2 should read between 0.98V to 1.02V.
VM3 should read above 3V.
3. Connect an oscilloscope voltage probe as shown in
Figure 3, between VOUT SNSE and GND SNSE turrets.
Set channel to AC-coupled, voltage scale to 20mV,
and time base to 10µs/div. Check V
Output voltage ripple can also be measured with a low
inductance connector on TP1, as shown in Figure 4.
4. Increase the load by 1A intervals up to 8A and observe
the voltage output regulation, ripple voltage and SW
behavior.
and efficiency measure-
OUT
ripple voltage.
OUT
DEMO MANUAL DC3205A
5. If other operation modes are desired. Turn off PS1, set
LD1 to 0A and set JP1 to FC/SYNC or BURST posi-
tion. Turn on PS1, slowly increase LD1 and observe
the change in PS1 output current, SW behavior and
output ripple.
6. Optional: To change the frequency, remove R5. Install
the desired R resistor in the R8 location. Size the
T
inductor, output capacitors and compensation com-
ponents to provide the desired inductor ripple and a
stable output. Refer to the LTC3314A data sheet and
LTPowerCAD for more information on choosing the
required components.
7. Optional: To SYNC to a specific frequency, set JP1 to
FC/SYNC position. Connect a waveform generator to
MODE/SYNC turret. Please refer to LTC3314A data
sheet for synchronization signal requirements.
8. To test the transient response with a base load, add the
desired resistor to produce a minimum load between
VOUT and RSNS turrets (RL shown on Figure 2).
Note that the total load resistance will be RL plus
R11 (20mΩ). Adjust a signal generator with a 10ms
period, 10% duty cycle and an amplitude from 1V to
2V to start.
9. Measure the R voltage to observe the current,
SNS
V /20mΩ. Adjust the amplitude of the pulse to
RSNS
provide the desired transient. Connect signal generator
SG1 between SG_INPUT and GND turrets. Adjust the
rising and falling edge of the pulse to provide the
desired ramp rate. Refer to the following equation for
output current measurement:
V
RSNS1
I =
OUT
20mΩ
10. When done, turn off SG1, PS1 and Load.
(1)
Rev. 0
3