Analog Devices Linear 2815A Demo Manual page 2

DEMO MANUAL DC2815A
QUICK START PROCEDURE
Using short twisted pair leads for any power connections
and with all loads and power supplies off, refer to Figure 1
for the proper measurement and equipment setup. The
Power Supply (PS1) should not be connected to the cir-
cuit until told to do so in the procedure below.
When measuring the input or output voltage ripple, care
must be taken to avoid a long ground lead on the oscil-
loscope probe. Measure the input or output voltage ripple
by touching the probe tip directly across the VIN or VOUT
and GND terminals, or by using an oscilloscope probe
tip jack.
1. Jumper and PS1 settings to start:
PS1 = OFF
LOAD = OFF
JP1 (EN) = ON
JP2 (MPPC) = OFF
JP3 (MODE) = FIXED FREQ
JP4 (PROG) = OFF
2. With power OFF connect the power supply (PS1) as
shown in Figure 1. If accurate current measurements
are desired (for efficiency calculations for example)
connect an ammeter in series with the supply as shown.
The ammeter is not required however.
3. Turn on PS1 and slowly increase voltage until the volt-
age at VIN is 12V.
2
4. Verify VOUT is ~5V.
5. Connect a 5A load to VOUT as shown in Figure 1 (1Ω
for VOUT = 5V). Connect an ammeter if accurate cur-
rent measurement or monitoring is desired.
6. VIN can now be varied between 2.5V and 26V. IOUT
needs to be reduced for VIN < VOUT to ensure VOUT
remains in regulation.
7. Load current (IOUT) can also be varied. The maximum
IOUT is a function of VIN and the current limit. Consult
the data sheet for more information on IOUT vs VIN.
For VIN > VOUT, IOUT can be increased to 6.5A. For
VIN < 5V, maximum IOUT is reduced. This reduction
is due to IIN increasing as VIN decreases. Once the
input current limit is reached, VOUT will drop out of
regulation.
NOTE: If VOUT drops out of regulation, check to be
sure the maximum load has not been exceeded, or
that VIN is not below the minimum value (2.5V).
8. For operation in BURST Mode move Jumper JP3 to
BURST. See the data sheet for more information.
9. For programmable output current limit feature move
JP4 to ILIM. Output current IOUT will now be limited
to 4A. See the data sheet for information on adjusting
the limit.
Rev. 0