Datasheet

LM1577, LM2577
SNOS658D –JUNE 1999–REVISED APRIL 2013 www.ti.com
Electrical Characteristics—LM1577-ADJ, LM2577-ADJ (continued)
Specifications with standard type face are for T
J
= 25°C, and those in bold type face apply over full Operating Temperature
Range. Unless otherwise specified, V
IN
= 5V, V
FEEDBACK
= V
REF
, and I
SWITCH
= 0.
Symbol Parameter Conditions Typical LM1577-ADJ LM2577-ADJ Units
Limit
(1)(2)
Limit
(3)
(Limits)
Error Amp V
FEEDBACK
= 1.0V to 1.5V ±200 μA
Output Current V
COMP
= 1.0V
±130/±90 ±130/±90 μA(min)
±300/±400 ±300/±400 μA(max)
I
SS
Soft Start Current V
FEEDBACK
= 1.0V 5.0 μA
V
COMP
= 0V
2.5/1.5 2.5/1.5 μA(min)
7.5/9.5 7.5/9.5 μA(max)
D Maximum Duty Cycle V
COMP
= 1.5V 95 %
I
SWITCH
= 100 mA
93/90 93/90 %(min)
ΔI
SWITCH
/ΔV
C
Switch 12.5 A/V
OMP
Transconductance
I
L
Switch Leakage V
SWITCH
= 65V 10 μA
Current V
FEEDBACK
= 1.5V (Switch Off)
300/600 300/600 μA(max)
V
SAT
Switch Saturation I
SWITCH
= 2.0A 0.5 V
Voltage V
COMP
= 2.0V (Max Duty Cycle)
0.7/0.9 0.7/0.9 V(max)
NPN Switch V
COMP
= 2.0V 4.3 A
Current Limit
3.7/3.0 3.7/3.0 A(min)
5.3/6.0 5.3/6.0 A(max)
THERMAL PARAMETERS (All Versions)
θ
JA
Thermal Resistance K Package, Junction to Ambient 35
θ
JC
K Package, Junction to Case 1.5
θ
JA
T Package, Junction to Ambient 65
θ
JC
T Package, Junction to Case 2
°C/W
θ
JA
N Package, Junction to Ambient
(6)
85
θ
JA
M Package, Junction to Ambient
(6)
100
θ
JA
S Package, Junction to Ambient
(7)
37
(6) Junction to ambient thermal resistance with approximately 1 square inch of pc board copper surrounding the leads. Additional copper
area will lower thermal resistance further. See thermal model in “Switchers Made Simple” software.
(7) If the DDPAK/TO-263 package is used, the thermal resistance can be reduced by increasing the PC board copper area thermally
connected to the package. Using 0.5 square inches of copper area, θ
JA
is 50°C/W; with 1 square inch of copper area, θ
JA
is 37°C/W;
and with 1.6 or more square inches of copper area, θ
JA
is 32°C/W.
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Product Folder Links: LM1577 LM2577