LM2673
All Output Voltage Versions
Electrical Characteristics
Limits appearing in
bold type face
apply over the entire junction temperature range of operation, −40˚C to 125˚C. Specifica-
tions appearing in normal type apply for T
A
= T
J
= 25˚C. Unless otherwise specified, R
ADJ
= 8.2KΩ, V
IN
=12V for the 3.3V, 5V
and Adjustable versions and V
IN
=24V for the 12V version.
Symbol
I
Q
Parameter
Quiescent
Current
V
FEEDBACK
= 8V
For 3.3V, 5.0V, and ADJ Versions
V
FEEDBACK
= 15V
For 12V Versions
V
ADJ
I
CL
I
L
Current Limit
Adjust Voltage
Current Limit
Output Leakage
Current
Switch
On-Resistance
Oscillator
Frequency
Duty Cycle
Feedback Bias
Current
Softstart
Threshold
Voltage
Softstart Pin
Current
Thermal
Resistance
Softstart Pin = 0V
T Package, Junction to Ambient
T Package, Junction to Ambient
θ
JC
θ
JA
θ
JA
θ
JA
θ
JC
θ
JA
θ
JA
T Package, Junction to Case
S Package, Junction to Ambient
S Package, Junction to Ambient
S Package, Junction to Ambient
S Package, Junction to Case
SD Package, Junction to Ambient
SD Package, Junction to Ambient
29
2
55
˚C/W
++
26
35
2
56
˚C/W
45
R
ADJ
= 8.2KΩ, (Note 5)
V
IN
= 40V, Softstart Pin = 0V
V
SWITCH
= 0V
V
SWITCH
= −1V
I
SWITCH
= 3A
Measured at Switch Pin
Maximum Duty Cycle
Minimum Duty Cycle
I
BIAS
V
SFST
V
FEEDBACK
= 1.3V
ADJ Version Only
1.21
4.5
1.0
6
0.15
260
91
0
85
225
1.181/1.169
3.8/3.6
1.229/1.246
5.25/5.4
1.5
15
0.17/0.29
280
V
A
mA
mA
Ω
kHz
%
%
nA
Conditions
Typ
4.2
Min
Max
6
Units
mA
DEVICE PARAMETERS
R
DS(ON)
f
O
D
0.63
0.53
0.74
V
I
SFST
θ
JA
θ
JA
3.7
65
6.9
µA
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