lm5015mhx National Semiconductor Corporation, lm5015mhx Datasheet - Page 21

• Manufacturer Part Number: lm5015mhx
• Description: High Voltage Monolithic Two-switch Forward Dc-dc Regulator
• Manufacturer: National Semiconductor Corporation

DC-DC TRANSFORMER
The DC-DC transformer shown in Figure 15 provides a 1:1
input voltage to output voltage conversion with ground isola-
tion. The circuit operates in open loop manner operating at
the maximum duty cycle limit of the LM5015. The power
transformer primary-secondary turns ratio is 1:2 (primary to
secondary). Therefore, at the maximum duty cycle of 0.5, the
FIGURE 15. DC-DC Transformer
21
output voltage will be approximately equal to the input volt-
age. A Zener diode Z1 is used at the output rail as a simple
means to protect the output against over-voltage under light
and no load conditions. The maximum load of this example
circuit is 0.3A, and the operating voltage range is from 5V to
15V.
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