2
DEMO MANUAL DC236
DESIGN-READY SWITCHERS
Frequency
FREQSET Pin Tied to INTV
CC
Pin
300kHz
Line Regulation
V
IN
= 7V to 20V; 3.3V and 5V Outputs
±
1mV
Load Regulation
I
O
= 0 to 3A; 3.3V and 5V Outputs
– 20mV
Supply Current
V
IN
= 15V, 5V and 3.3V On, EXTV
CC
= V
OUT1
390
µ
A
Shutdown Current
V
IN
= 15V, STBYMD = 0V
20
µ
A
Standby Current
5V INTV
CC
and 3.3V LDO On; V
IN
= 15V, RUN/SS1 and RUN/SS2 = 0V, 1M
Ω
STBYMD to V
IN
125
µ
A
Efficiency
V
IN
= 15V, 5V at 3A and 3.3V at 3A
94%
Operating Temperature Range: 0
°
C to 50
°
C (continued from Page 1)
QUICK START GUIDE
This demonstration board is easily set up to evaluate the
performance of the LTC1628. Please follow the proce-
dure outlined below for proper operation.
1. Refer to Figure 1 for board orientation and proper
measurement equipment setup.
2. Place the jumpers as shown in the diagram. Tempo-
rarily leave off the STBYMD and FCB jumpers.
3. Connect the desired loads between V
OUT1
, V
OUT2
and
their closest PGND terminals on the board. The loads
can be up to 4A for V
OUT1
and 4A for V
OUT2
. Soldered
wires should be used when the load current exceeds
1A in order to achieve optimum performance.
4. Connect the input power supply to the V
IN
and GND
terminals on the right, center of the board. Do
not
increase V
IN
over 30V or the
MOSFETs may be dam-
aged. The recommended V
IN
to start is < 7V.
5. Switch on the desired channel(s) by removing the
RUN/SS1 or RUN/SS2 jumper.
6. Measure V
OUT1
and V
OUT2
to verify output voltages of
5V
±
0.1V and 3.3V
±
0.067V, respectively, at load
currents of up to 3A each.
7. Active loads can cause confusing results. Refer to
the active load discussion in the Operation section.
The circuit shown in Figure 2 provides fixed voltages of 5V
and 3.3V at currents of up to 4A. Figure 1 illustrates the
correct measurement setup in order to verify the typical
numbers found in the Performance Summary table. Small
spring clip leads are very convenient for small-signal
bench testing but should not be used at the current and
impedance levels associated with this switching regulator.
Soldered wire connections are required to properly ascer-
tain the performance of this demonstration PC board. Do
not tie the grounds together off the test board.
The six jumpers on the left side of the board are settable
as follows: the center pin is connected to ground when the
jumper is in the rightmost position. The center pin is
connected to a positive bias source when the jumper is in
the leftmost position.
A
LOAD
LOAD
5V
V
OUT1
V
OUT2
V
V
A
A
V
V
IN
1
RUN/SS1
FLTCPL
FREQ
STBYMD
FCB
RUN/SS2
0
GND
5V
GND
GND
LTC1628
MULTI-PHASE SYSTEM POWER
DEMO CIRCUIT DC236
V
IN
3.3V
3.3V
DC236 F01
L1
L2
+
Figure 1. Proper Measurement Setup
PERFOR A CE SU ARY
U
W
WW
EASURE E T SETUP
U
W
W
