LM2585SX-ADJ National Semiconductor, LM2585SX-ADJ Datasheet - Page 5

• Manufacturer Part Number: LM2585SX-ADJ
• Description: IC,SMPS CONTROLLER,CURRENT-MODE,BIPOLAR,SIP,5PIN,PLASTIC
• Manufacturer: National Semiconductor

Specifications of LM2585SX-ADJ

• Rohs Compliant: NO

Electrical Characteristics (All Versions)
Note 3: The junction temperature of the device (T
dissipation of the device (P
(MAX)
allowable power dissipation, derate the maximum junction temperature — this ensures a margin of safety in the thermal design.
Note 4: External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM2585 is used as
shown in Figures Figure 2 and Figure 3 , system performance will be as specified by the system parameters.
Note 5: All room temperature limits are 100% production tested, and all limits at temperature extremes are guaranteed via correlation using standard Statistical Qual-
ity Control (SQC) methods.
Note 6: A 1.0 M
Note 7: To measure this parameter, the feedback voltage is set to a low value, depending on the output version of the device, to force the error amplifier output high.
Adj: V
Note 8: To measure this parameter, the feedback voltage is set to a high value, depending on the output version of the device, to force the error amplifier output low.
Adj: V
Note 9: To measure the worst-case error amplifier output current, the LM2585 is tested with the feedback voltage set to its low value (specified in (Note 7) and at
its high value (specified in (Note 8) .
Note 10: Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with
board with minimum copper area.
Note 11: Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with
containing approximately 4 square inches of (1oz.) copper area surrounding the leads.
Note 12: Junction to ambient thermal resistance for the 5 lead TO-263 mounted horizontally against a PC board area of 0.136 square inches (the same size as the
TO-263 package) of 1 oz. (0.0014 in. thick) copper.
Note 13: Junction to ambient thermal resistance for the 5 lead TO-263 mounted horizontally against a PC board area of 0.4896 square inches (3.6 times the area
of the TO-263 package) of 1 oz. (0.0014 in. thick) copper.
Note 14: Junction to ambient thermal resistance for the 5 lead TO-263 mounted horizontally against a PC board copper area of 1.0064 square inches (7.4 times the
area of the TO-263 package) of 1 oz. (0.0014 in. thick) copper. Additional copper area will reduce thermal resistance further. See the thermal model in Switchers Made
Simple software.
Typical Performance Characteristics
Supply Current
vs Temperature
Supply Current
vs Switch Current
. For a safe thermal design, check that the maximum power dissipated by the device is less than: P
FB
FB
= 1.05V; 3.3V: V
= 1.41V; 3.3V: V
resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring A
FB
FB
D
). A thermal shutdown will occur if the temperature exceeds the maximum junction temperature of the device: P
= 2.81V; 5.0V: V
= 3.80V; 5.0V: V
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FB
FB
= 4.25V; 12V: V
= 5.75V; 12V: V
J
) is a function of the ambient temperature (T
Reference Voltage
vs Temperature
Current Limit
vs Temperature
FB
FB
= 10.20V.
= 13.80V.
5
(Continued)
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A
), the junction-to-ambient thermal resistance (
D
[T
J(MAX)
vs Supply Voltage
Feedback Pin Bias
Current vs Temperature
Reference Voltage
− T
A(MAX)
)]/
1
1
⁄
⁄
2
2
JA
inch leads soldered to a PC board
inch leads in a socket, or on a PC
. When calculating the maximum
VOL
D
.
x
JA
JA
), and the power
+ T
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A(MAX)
T
J -