Linear Technology DC1707 Demo Manual page 2

DEMO MANUAL DC1707
QUICK START PROCEDURE
Demonstration circuit 1707 allows the user to quickly
evaluate the performance of the LTC3617. Refer to Figure 1
for proper measurement equipment setup and follow the
procedure below
1. Place jumpers in the following positions.
JP2 - EXT REF (lower)
JP1 - RUN (lower)
JP3 - V (upper)
IN
2. With both power supplies turned down and switched
off, connect the supplies and digital voltmeters and
ammeters as shown in Figure 1.
3. Switch on the input supply and adjust for approximately
3.3V on V , and set the Reference supply to 1.800V
IN
on V .
DDQIN
4. Verify that the VTTR voltmeter is exactly one-half of
V ±18mV or approximately 900mV.
DDQIN
5. Verify that the VTT voltmeter reading is equal to the
VTTR value ±10mV.
2
6. To evaluate sourcing current from the VTT terminal,
connect one lead of a 0.2Ω 5W load resistor to the
VTT terminal and the other lead to the GND terminal.
Verify that the voltmeter measurements still meet the
specifications shown in the table on page 1.
7. To evaluate sinking current into the VTT terminal, connect
one lead of a 0.5Ω 10 or 20W load resistor to the VTT
terminal and the other lead to the V
that the voltmeter measurements meet the specifications
in the Performance Summary table on the front page.
NOTE. When measuring the input or output voltage ripple,
care must be taken to avoid a long ground lead on the
oscilloscope probe. Measure the input or output voltage
ripple by touching the probe tip directly across the V
V and GND terminals. See Figure 2 for proper scope
OUT
probe technique.
NOTE. Additional pads for are located on the board back-
side for larger compensation components for optimizing
loop compensation.
terminal. Verify
IN
or
IN
dc1707f