DEMO MANUAL DC2016A
LTM8054
36V
IN
, 5.4A Buck-Boost
μModule Regulator
Description
Demonstration circuit 2016A features the
LTM8054,
a
synchronous buck-boost μModule regulator that accepts
input voltages lower, higher or the same as the output,
but is also highly efficient due to its four-switch archi-
tecture. The output for DC2016A is 12V and the input
voltage range is 6V to 35V – see the LTM8054 data sheet
for application circuits with input voltages up to 36V.
The maximum output current of DC2016A is 3A and the
switching frequency is 600kHz.
DC2016A supports the adjustable and controllable features
of the LTM8054 including output voltage and current
regulation, switching frequency, RUN threshold, soft-
start period, synchronization and reverse inductor current
inhibit. In most cases, adjustment is made by modifying
the appropriate resistor or capacitor component(s).
DC2016A provides output current monitoring and a clock
output. Input current monitoring and regulation requires
the installation of a current sense resistor. The SV
IN
input
for controller power can be made a diode-OR of power
V
IN
and the output voltage to extend the operating range
of power V
IN
to lower voltages. There are places to mount
optional components that add an LC input filter and also a
unity gain buffer to operate multiple DC2016As in parallel.
The LTM8054 data sheet must be read in conjunction with
this demo manual to properly use or modify DC2016A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2016A
L,
LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
BoarD photo
dc2016af
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DEMO MANUAL DC2016A
performance summary
PARAMETER
Minimum Input Voltage, V
IN
Maximum Input Voltage, V
IN
Maximum Output Current, I
OUT
Input Turn-On Voltage, V
IN
Input Turn-Off Voltage, V
IN
Output Voltage, V
OUT
Efficiency
Switching Frequency
Output Current Limit
12V < V
IN
< 35V, CTL = OPEN
V
IN
= 6V, CTL = OPEN
R10 = 332k, R11 = 121k, V
IN
Rising
R10 = 332k, R11 = 121k, V
IN
Falling
100mA < I
OUT
< 3A (See Figure 2), R2 = 11k
1%, R3 = 100k 1%, R4 = 0.015Ω
V
IN
= 24V, I
OUT
= 3A
R1 = 36.5k
R4 = 0.015Ω
11.7
92
600
3.6
35
3
1.8
5.5
4.5
12.5
Specifications are at T
A
= 25°C
CONDITIONS
MIN
TYP
MAX
6
UNITS
V
V
A
A
V
V
V
%
kHz
A
2
dc2016af
DEMO MANUAL DC2016A
Quick start proceDure
To use DC2016A to evaluate the performance of the
LTM8054, refer to Figure 1 for the proper measurement
equipment setup, Figure 2 for the maximum output current
versus input voltage and then follow the procedure below:
NOTE: Do not hot-plug the V
IN
terminal at high input volt-
ages. The absolute maximum voltage rating for V
IN
of the
LTM8054 is 40V and hot-plugging a power supply through
wire leads to the demonstration circuit can cause the voltage
on the extremely low ESR ceramic input capacitor to ring
to twice its DC value. In order to protect the LTM8054, an
aluminum electrolytic capacitor with higher ESR is placed
at the input terminals. This may protect against some, but
not all, input transients due to a hot-plugged power supply.
See Application Note 88 for more details.
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 to terminals across
the V
IN
or V
OUT
capacitors. See Figure 3 for proper scope
probe technique. Solder terminals near the input or output
capacitors, if necessary.
1. Connect the RUN terminal to ground with a clip-on lead.
Connect the power supply (with power off), load, and
meters as shown in Figure 1.
2. After all connections are made, turn on the input power
and verify that the input voltage is between 6V and 35V
3. Remove the clip-on lead from RUN. Verify that V
OUT
is
12V.
NOTE: If V
OUT
is too low, temporarily disconnect the load
to make sure that the load is not set too high.
Once the proper output voltage is established, adjust the
input voltage and load within the operating range and
observe the output voltage regulation, ripple voltage, ef-
ficiency and other parameters.
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DEMO MANUAL DC2016A
Quick start proceDure
REMOVABLE CONNECTION
IS OPTIONAL FOR PROPER
START-UP
–
+
OPTIONAL
2V
0V
+
+
–
–
+
–
OPTIONAL WITH
R7 = OPEN
3.3V
0V
0V TO 35VDC
4A
–
+
+
12VDC
0A TO 3A
–
+
–
DC2016 F01
Figure 1. Proper Measurement Equipment Setup
4
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DEMO MANUAL DC2016A
Quick start proceDure
6
MAXIMUM OUTPUT CURRENT (A)
5
R4 = SHORT
4
3
2
1
0
R4 = 0.015
12V
OUT
0
6
12
18
24
INPUT VOLTAGE (V)
30
36
dc2016 F02
Figure 2. Maximum Output Current vs Input Voltage for V
OUT
= 12V
C13
V
OUT
GND
Figure 3. Proper Scope Probe Technique
0
–10
–20
INTENSITY (dBm)
–30
–40
–50
–60
–70
–80
–90
–100
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
FREQUENCY (MHz)
dc2016 F04
Figure 4. Conducted V
OUT
Noise Spectrum Using HP 4395A Spectrum
Analyzer and 41800A Active Probe. V
IN
= 24V and V
OUT
= 12V at 3A
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