lm2588sx-adj National Semiconductor Corporation, lm2588sx-adj Datasheet - Page 6

• Manufacturer Part Number: lm2588sx-adj
• Description: Simple Switcher 5a Flyback Regulator With
• Manufacturer: National Semiconductor Corporation

www.national.com
I
V
I
V
I
θ
θ
θ
θ
θ
θ
θ
CL
SYNC
SH
JA
JA
JC
JA
JA
JA
JC
STH
SHTH
Symbol
All Output Voltage Versions Electrical Characteristics
Specifications with standard type face are for T
Range. Unless otherwise specified, V
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. These ratings apply when the current is limited to less than
1.2 mA for pins 1, 2, 3, and 6. Operating ratings indicate conditions for which the device is intended to be functional, but device parameter specifications may not
be guaranteed under these conditions. For guaranteed specifications and test conditions, see the Electrical Characteristics.
Note 2: Note that switch current and output current are not identical in a step-up regulator. Output current cannot be internally limited when the LM2588 is used as
a step-up regulator. To prevent damage to the switch, the output current must be externally limited to 5A. However, output current is internally limited when the
LM2588 is used as a flyback regulator (see the Application Hints section for more information).
Note 3: The junction temperature of the device (T
dissipation of the device (P
T
maximum 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 LM2588 is used as
shown in Figure 1 and Figure 2, 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
Quality Control (SQC) methods.
Note 6: A 1.0 MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring A
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
and the switch on.
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 and the switch off.
Note 9: To measure the worst-case error amplifier output current, the LM2588 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: When testing the minimum value, do not sink current from this pin — isolate it with a diode. If current is drawn from this pin, the frequency adjust circuit
will begin operation (see Figure 41).
Note 11: Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with
PC board with minimum copper area.
Note 12: Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with
containing approximately 4 square inches of (1 oz.) copper area surrounding the leads.
Note 13: Junction to ambient thermal resistance for the 7 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 14: Junction to ambient thermal resistance for the 7 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 15: Junction to ambient thermal resistance for the 7 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
J(MAX)
. For a safe thermal design, check that the maximum power dissipated by the device is less than: P
®
NPN Switch Current
Limit
Synchronization
Threshold Voltage
Synchronization
Pin Current
ON /OFF Pin (Pin 1)
Threshold Voltage
ON /OFF Pin (Pin 1)
Current
Thermal Resistance
software.
Parameters
D
). A thermal shutdown will occur if the temperature exceeds the maximum junction temperature of the device: P
F
V
V
V
V
(Note 10)
V
V
T Package, Junction to Ambient
(Note 11)
T Package, Junction to Ambient
(Note 12)
T Package, Junction to Case
S Package, Junction to Ambient
(Note 13)
S Package, Junction to Ambient
(Note 14)
S Package, Junction to Ambient
(Note 15)
S Package, Junction to Case
SYNC
COMP
IN
COMP
COMP
COMP
SH
IN
= 5V
= V
J
) is a function of the ambient temperature (T
= 5V.
= 200 kHz
= 1V, V
= 1V, V
= 1V
= 1V
SHTH
Conditions
J
= 25˚C, and those in bold type face apply over full Operating Temperature
IN
SYNC
= 5V
= V
STH
6
Typical
0.75
A
100
6.5
1.6
40
65
45
56
35
26
), the junction-to-ambient thermal resistance (θ
2
2
0.625/0.40
D
1.0/0.8
≤ [T
15/10
Min
5.0
(Note 5) (Continued)
J(MAX)
− T
1
⁄
2
A(MAX)
inch leads soldered to a PC board
1
⁄
2
inch leads in a socket, or on a
0.875/1.00
]/θ
2.2/2.4
65/75
JA
VOL
Max
200
9.5
. When calculating the
.
D
JA
x θ
), and the power
JA
+ T
A(MAX)
Units
˚C/W
µA
µA
A
V
V
≥