LM2598S-ADJ National Semiconductor, LM2598S-ADJ Datasheet - Page 20

• Manufacturer Part Number: LM2598S-ADJ
• Description: SIMPLE SWITCHER Power Converter 150 kHz 1A Step-Down Voltage Regulator/ with Features
• Manufacturer: National Semiconductor

www.national.com
Application Information
the narrow pulses and ramp up in a controlled manner. This
is a very useful feature in some switcher topologies that re-
quire large startup currents (such as the inverting configura-
tion) which can load down the input power supply.
Note: The lower curve shown in Figure 13 shows the Soft-start region from
4. Normal operation. Above 2.8V, the circuit operates as a
standard Pulse Width Modulated switching regulator. The
capacitor will continue to charge up until it reaches the inter-
nal clamp voltage of approximately 7V. If this pin is driven
from a voltage source, the current must be limited to about
1 mA.
0% to 100%. This is not the duty cycle percentage, but the output volt-
age percentage. Also, the Soft-start voltage range has a negative tem-
perature coefficient associated with it. See the Soft-start curve in the
electrical characteristics section.
FIGURE 14. Timing Diagram for 5V Output
(Continued)
20
FIGURE 13. Soft-start, Delay, Error, Output
DS012593-31
DS012593-30