All Output Voltage Versions
Electrical Characteristics
Limits appearing in
bold type face
apply over the entire junction temperature range of operation, 40C to 125C.
Specifications appearing in normal type apply for T
= T
J
= 25C. Unless otherwise specified V
IN
=12V for the 3.3V, 5V and
Adjustable versions and V
IN
=24V for the 12V version.
Symbol
Parameter
Conditions
DEVICE PARAMETERS
I
Q
Quiescent
Current
For 3.3V, 5.0V, and ADJ Versions
V
FEEDBACK
= 15V
For 12V Versions
V
ADJ
Current Limit
Adjust Voltage
I
CL
Current Limit
R
ADJ
= 5.6K
, (Note 5)
I
L
Output
Leakage
Current
V
SWITCH
= 1V
R
DS(ON)
Switch
On-Resistance
f
O
Oscillator
Frequency
D
Duty Cycle
Maximum Duty Cycle
Minimum Duty Cycle
I
BIAS
Feedback Bias
Current
ADJ Version Only
V
SFST
Softstart
Threshold
Voltage
I
SFST
Softstart Pin
Current
θ
JA
Thermal
Resistance
(Note 6)
θ
JA
T Package, Junction to Ambient
(Note 7)
θ
JC
T Package, Junction to Case
θ
JA
S Package, Junction to Ambient
(Note 8)
θ
JA
S Package, Junction to Ambient
(Note 9)
θ
JA
S Package, Junction to Ambient
(Note 10)
θ
JC
S Package, Junction to Case
Typ
Min
Max
Units
V
FEEDBACK
= 8V
4.2
6
mA
1.21
1.181/
1.169
1.229/
1.246
V
6.3
5.5/
5.3
7.6/
8.1
A
V
IN
= 40V, Softstart Pin = 0V
V
SWITCH
= 0V
1.0
6
0.12
1.5
15
mA
mA
I
SWITCH
= 5A
0.14/
0.225
Measured at Switch Pin
260
225
280
kHz
91
0
85
%
%
nA
V
FEEDBACK
= 1.3V
0.63
0.53
0.74
V
Softstart Pin = 0V
3.7
6.9
μA
T Package, Junction to Ambient
65
45
2
56
C/W
35
26
2
++
Note 1:
Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings indicate conditions under which of the device is
guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test condition, see the electrical Char-
acteristics tables.
Note 2:
ESD was applied using the human-body model, a 100pF capacitor discharged through a 1.5 k
resistor into each pin.
Note 3:
Typical values are determined with T
A
= T
J
= 25C and represent the most likely norm.
Note 4:
All limits are guaranteed at room temperature (standard type face) and at
temperature extremes (bold type face)
. All room temperature limits are 100%
tested during production with T
= T
= 25C. All limits at temperature extremes are guaranteed via correlation using standard standard Quality Control (SQC) meth-
ods. All limits are used to calculate Average Outgoing Quality Level (AOQL).
Note 5:
The peak switch current limit is determined by the following relationship: I
CL
=37,125/ R
ADJ
.
Note 6:
Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with
1
2
inch leads in a socket, or on a PC
board with minimum copper area.
Note 7:
Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with
1
2
inch leads soldered to a PC board
containing approximately 4 square inches of (1 oz.) copper area surrounding the leads.
L
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