Texas Instruments Evaluation Board for the LM5015 LM5015ISOEVAL/NOPB LM5015ISOEVAL/NOPB 데이터 시트
제품 코드
LM5015ISOEVAL/NOPB
Isolated Two-Switch Forward DC-DC Regulator
The evaluation board can be synchronized to an external clock of faster than the board's native oscillator
frequency, which is twice the switching frequency F
frequency, which is twice the switching frequency F
SW
. Note that the LM5015 oscillator uses a divide-by-2
circuit and the actually switching frequency is half the oscillator frequency set by R2. Since the evaluation
board's switching frequency is 300 kHz, the external clock should be faster than 600 kHz. The external
clock signal should feed into the plated via hole of the SYNC port, referenced to the AGND node. Refer to
the LM5015 datasheet for the requirement of the external clock signal for successful synchronization.
board's switching frequency is 300 kHz, the external clock should be faster than 600 kHz. The external
clock signal should feed into the plated via hole of the SYNC port, referenced to the AGND node. Refer to
the LM5015 datasheet for the requirement of the external clock signal for successful synchronization.
The evaluation board can be remote controlled for enabling and disabling. The control port on the PC
board is the plated via hole dedicated to EN node. The remote control signal should be referenced to the
AGND node. Refer to the LM5015 datasheet for detailed information of remote control.
board is the plated via hole dedicated to EN node. The remote control signal should be referenced to the
AGND node. Refer to the LM5015 datasheet for detailed information of remote control.
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Isolated Two-Switch Forward DC-DC Regulator
shows the schematic of the evaluation board in a default configuration of a Two-Switch Forward
DC-DC regulator. The two MOSFET switches are integrated in the LM5015, and the regulator is
implemented without using any discrete power MOSFET. A transformer winding between pins 4 and 5 of
T1 is used to produce 10V Vcc for the LM5015, thus blocking the internal LDO regulator during normal
operation and improving efficiency. Refer to
implemented without using any discrete power MOSFET. A transformer winding between pins 4 and 5 of
T1 is used to produce 10V Vcc for the LM5015, thus blocking the internal LDO regulator during normal
operation and improving efficiency. Refer to
for the schematic of optional Isolated Two-Switch
Flyback DC-DC Regulator.
Figure 2. Schematic of Isolated Two Forward DC-DC Regulator (Factory Default)
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Board Layout and Probing
The following should be kept in mind when the board is powered:
•
The LM5015, and the diodes D3 and D4 will be hot to the touch when operating at high input voltage
and/or high load current.
and/or high load current.
•
Use CAUTION when probing the circuit at high input voltages. 72 volts is enough to produce shocks
and sparks.
and sparks.
•
At maximum load current (3A), the wire size and length used to connect the load become important.
Ensure there is not a significant voltage drop along the wires.
Ensure there is not a significant voltage drop along the wires.
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SNVA291A – October 2007 – Revised April 2013
AN-1724 LM5015 Isolated Two-Switch DC-DC Regulator Evaluation Board
Copyright © 2007–2013, Texas Instruments Incorporated