LTM460
7EV
1
DESCRIPTION
Demonstration circuit DC1601A is a poly-phase power
supply featuring the LTM4607 Power module, a complete
high efficiency switching mode buck-boost power supply.
The DC1601A input voltage range is from 6V to 36V and
is capable of delivering high power through paralleled
LTM4607 modules. The demo circuit can deliver up to
10A of output current for 2 paralleled modules
(DC1601A-A), 15A for 3 paralleled modules (DC1601A-B)
and up to 20A for 4 paralleled modules (DC1601A-C). The
DC1601A demonstrates that paralleling modules is easy
and reliable.
The output voltage for the board is 12V. The rated load
current per module is 5A, however current de-rating may
be necessary under certain V
IN
, V
OUT
, frequency, and
thermal conditions. An on-board external clock is pro-
vided for synchronization and interleaving of phases to
minimize input and output ripple. An internal phase-
locked loop allows the LTM4607 to be synchronized to an
external clock within the range of 200 kHz to 400 kHz.
The LTM4607 default switching frequency on the
DC1601A is set to 300 kHz through the on-board
LTC6902 clock generator which interleaves the paralleled
phases. The frequency and phase separation set by the
LTC6902 are resistor programmable.
These features, including the availability of the LTM4607
in a compact thermally enhanced 15mmx15mmx2.8mm
LGA package make the demonstration circuit ideal for use
in high-density point of load regulation applications.
Design files for this circuit board are available. Call
the LTC Factory.
, LTC, LT and LTM are registered trademarks of Linear Technology Corporation.
Table 1.
Performance Summary
PARAMETER CONDITIONS / NOTES VALUE
Maximum Input Voltage 36V
Minimum Input Voltage 6V
Output Voltage V
OUT
Programmed by R22 12V
Maximum Continuous Output Current I
OUT
MAX
Current de-rating may be ne-
cessary for certain V
IN
, V
OUT
, fre-
quency and thermal conditions.
10A
DC
(DC1601A-A)
15A
DC
(DC1601A-B)
20A
DC
(DC1601A-C)
Default Operating Frequency 300kHz
External Clock Sync. frequency range 200kHz – 400kHz
Output voltage ripple (typical) V
OUT
= 12V
300kHz (20MHz BW)
V
IN
= 9V, I
OUT
= 10A (DC1601A-A), See Fig. 5a
V
IN
= 12V, I
OUT
= 15A (DC1601A-B), See
Fig. 5b
V
IN
=32V, I
OUT
=20A (DC1601A-B), See Fig. 5c
Efficiency V
IN
= 9V, V
OUT
= 12V 300kHz
95.7% @ I
OUT
= 10A (DC1601A-A), See Fig. 2a
94.8% @ I
OUT
= 15A (DC1601A-B), See Fig. 2b
94.8% @ I
OUT
= 20A (DC1601A-C), See Fig. 2c
Load Transient V
OUT
= 12V
300kHz (20MHz BW)
V
IN
= 9V, I
OUT
= 10A (DC1601A-
A), See Fig. 4a
V
IN
= 12V, I
OUT
= 15A (DC1601A-
B), See Fig. 4b
V
IN
=32V, I
OUT
=20A (DC1601A-B), See Fig. 4c
DEMO
CIRCUIT
1
601
A
QUICK START GUIDE
LTM
®
46
0
7
E
V
High Efficiency Poly-Phase Buck-
Boost
Power Supply
LTM460
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QUICK START PROCEDURE
Demonstration circuit DC1601A is easy to set up to eva-
luate the performance of paralleled LTM4607 modules.
Please refer to Figure 1 for proper measurement equip-
ment setup and follow the procedure below:
1. With power off, connect the input power sup-
ply, load, and meters as shown in Figure 1.
Preset the load to 0A and V
IN
supply to be 0V.
Place jumpers in the following positions for a
typical 12V
OUT
application:
JP2 JP1
JP3
MODE
RUN START
CCM OFF SSO
2. Turn on the power at the input. Increase V
IN
to
18V (Do not hot-plug the input supply or apply
more than the rated maximum voltage of 36V
to the board or the modules may be dam-
aged).
3. Set the run pin jumper (JP1) to the ON posi-
tion. The output voltage should be regulated.
The output voltage meter should read 12V
±
2%
(11.76V-12.24V).
4. Vary the input voltage from 6V-36V and adjust
the load current from 0-10A (for DC1601A-A),
0-15A (for DC1601A-B), 0-20A (for DC1601A-
C). V
OUT
should remain regulated at 12V
±
2%
(11.76V-12.24V). Observe the load regulation,
efficiency and other parameters.
5. Set the load current to 0A. Set the RUN pin
jumper (JP1) to the OFF position. Turn off in-
put supply before disconnecting the circuit.
Figure 1.
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Figure 2a: Measured Efficiency at 12V
OUT
, 300 kHz (DC1601A-A)
Figure 2c: Measured Efficiency at 12V
OUT
, 300 kHz (DC1601A-C)
Figure 2b: Measured Efficiency at 12V
OUT
, 300 kHz (DC1601A-B) Figure 3b: Thermal capture at 12V
IN
, 12V
OUT,
, 15A, 300kHz (DC1601A-B)
No Forced Airflow (Convection)
Figure 3a: Thermal capture at 6V
IN
, 12V
OUT,
, 10A, 300kHz (DC1601A-A)
No Forced Airflow (Convection)
Figure 3c: Thermal capture at 32V
IN
, 12V
OUT,
, 20A, 300kHz (DC1601A-C)
No Forced Airflow (Convection)
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DC1601A-A: V
IN
= 9V, V
OUT
= 12V, I
OUT
DC = 5A,
I
OUT
Step = 5A, f
SW
= 300 kHz
Figure 4a. Measured Load Step Response (DC1601A-A)
I
OUT
Step (5A/div)
V
OUT
(50mV/div)
Figure 4b. Measured Load Step Response (DC1601A-B)
V
OUT
(20mV/div)
I
OUT
Step (5A/div)
Figure 4c. Measured Load Step Response (DC1601A-C)
I
OUT
Step (20A/div)
V
OUT
(200mV/div)
DC1601A-A: V
IN
= 9V, V
OUT
= 12V, I
OUT
= 10A,
f
SW
= 300 kHz
Figure 5a: Measured Output Voltage Ripple (DC1601A-A)
Figure 5b: Measured Output Voltage Ripple (DC1601A-B)
Figure 5c: Measured Output Voltage Ripple (DC1601A-C)
V
OUT
(20mV/div)
V
OUT
(20mV/div)
V
OUT
(20mV/div)
DC1601A-B: V
IN
= 12V, V
OUT
= 12V, I
OUT
DC = 7.5A,
I
OUT
Step = 7.5A, f
SW
= 300 kHz
DC1601A-C: V
IN
= 32V, V
OUT
= 12V, I
OUT
DC = 10A,
I
OUT
Step = 7.5A, f
SW
= 300 kHz
DC1601A-A: V
IN
= 12V, V
OUT
= 12V, I
OUT
= 15A,
f
SW
= 300 kHz
DC1601A-C: V
IN
= 32V, V
OUT
= 12V, I
OUT
= 20A,
f
SW
= 300 kHz
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