DESCRIPTION
DEMO MANUAL DC2341A
LTC7130EY
20V 20A Monolithic Buck Converter
with Ultra-Low DCR Sensing
Demonstration circuit 2341A is a high efficiency synchronous buck DC/DC converter with 4.5V to 20V input
range. It can supply 20A maximum load current at 1.5V
®
output. The demo board features the LT C
7130 regulator.
No external MOSFETs are required. It employs an LTC
proprietary current sensing, current mode architecture,
allowing the use of a very low DC resistance (DCR) power
inductor to maximize efficiency in high current applica
tions. Differential output voltage sensing along with a
precision internal reference combine to offer accurate
output regulation. The LTC7130 is housed in a 6.25mm
or forced continuous mode (CCM) operation. The converter
can also be externally synchronized through the MODE/
PLLIN pin (MODE/PLLIN terminal on the board; JP2: no
jumper or BURST position). To shut down the converter,
one simple way is to force the RUN pin below 1.1V (JP1:
OFF). The power good output (PGOOD terminal) is low
when the output voltage is outside of the ±10% regula
-
tion window.
The LTC7130 data sheet gives a complete description of
the operation and application information. The data sheet
must be read in conjunction with this demo manual.
× 7.5mm × 2.22mm 63-pin BGA package.
Design files for this circuit board are available at
The light load operation mode of the converter is deter
mined with the MODE/PLLIN pin. Use the JP2 jumper to
®
select pulse-skipping mode (P.S.), Burst Mode
PERFORMANCE SUMMARY
PARAMETER CONDITIONS MIN TYP MAX UNITS
Input Voltage Range 4.5 20 V
Output Voltage V
Maximum Output Current V
Typical Switching Frequency 530 kHz
Typical Efficiency V
Typical Output Voltage Ripple V
(BURST)
Specifications are at TA = 25°C
-
= 4.5V to 20V, I
IN
= 4.5V to 20V, V
IN
= 12V, I
IN
IN
= 12V, I
OUT
OUT
http://www.linear.com/demo/DC2341A
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
= 0A to 20A 1.5 ±2% V
OUT
= 1.5V 20 A
OUT
= 20A 89.2 %
= 20A 25 mV
P-P
-
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1
DEMO MANUAL DC2341A
QUICK START PROCEDURE
Demonstration circuit 2341A is easy to set up to evaluate
the performance of the LTC7130. Refer to Figure 1 for
the proper measurement equipment setup and follow the
procedure below:
1. With power off, connect the input power supply to V
(4.5V to 20V) and GND (input return).
2. Connect the 1.5V output load between V
(Initial load: no load).
3. Connect the DVMs to the input and outputs.
4. Turn on the input power supply and check for the proper
output voltages. V
should be 1.5V ±2%.
OUT
and GND
OUT
IN
5. Once the proper output voltages are established, adjust
the loads within the operating range and observe the
output voltage regulation, ripple voltage and other
parameters.
NOTE: When measuring the output or input voltage ripple,
do not use the long ground lead on the oscilloscope probe.
See Figure 2 for the proper scope probe technique. Short,
stiff leads need to be soldered to the (+) and (–) terminals
of an output capacitor. The probe’s ground ring needs to
touch the (–) lead and the probe tip needs to touch the
(+) lead.
2
Figure 1. Proper Measurement Equipment Setup
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