LM2674
LM2674-ADJ
Symbol
η
Parameter
Efficiency
(Continued)
Conditions
V
IN
= 12V, I
LOAD
= 500 mA
Typ
90
Min
Max
%
Units
All Output Voltage Versions
Specifications with standard type face are for T
J
= 25˚C, and those with
bold type face
apply over
full Operating Tempera-
ture Range.
Unless otherwise specified, V
IN
= 12V for the 3.3V, 5V, and Adjustable versions and V
IN
= 24V for the 12V ver-
sion, and I
LOAD
= 100 mA.
Symbol
I
Q
Parameters
Quiescent Current
Conditions
V
FEEDBACK
= 8V
For 3.3V, 5.0V, and ADJ Versions
V
FEEDBACK
= 15V
For 12V Versions
I
STBY
I
CL
I
L
Standby Quiescent
Current
Current Limit
Output Leakage Current
V
IN
= 40V, ON/OFF Pin = 0V
V
SWITCH
= 0V
V
SWITCH
= −1V, ON/OFF Pin = 0V
R
DS(ON)
f
O
D
I
BIAS
V
S/D
I
S/D
θ
JA
Switch On-Resistance
Oscillator Frequency
Maximum Duty Cycle
Minimum Duty Cycle
Feedback Bias
Current
ON/OFF Pin
Voltage Thesholds
ON/OFF Pin Current
Thermal Resistance
ON/OFF Pin = 0V
N Package, Junction to Ambient (Note 6)
M Package, Junction to Ambient (Note 6)
V
FEEDBACK
= 1.3V
ADJ Version Only
I
SWITCH
= 500 mA
Measured at Switch Pin
ON/OFF Pin = 0V
50
0.8
1
6
0.25
260
95
0
85
1.4
20
95
105
0.8
7
2.0
37
225
0.62/0.575
100/150
1.2/1.25
25
15
0.40/0.60
275
µA
A
µA
mA
Ω
kHz
%
%
nA
V
µA
˚C/W
2.5
mA
Typ
2.5
Min
Max
3.6
Units
mA
DEVICE PARAMETERS
Note 1:
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. 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:
The human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin.
Note 3:
External components such as the catch diode, inductor, input and output capacitors, and voltage programming resistors can affect switching regulator
performance. When the LM2674 is used as shown in
Figures 2, 3
test circuits, system performance will be as specified by the system parameters section of the
Electrical Characteristics.
Note 4:
Typical numbers are at 25˚C and represent the most likely norm.
Note 5:
All limits guaranteed at room temperature (standard type face) and at
temperature extremes (bold type face).
All room temperature limits are 100%
production tested. All limits at
temperature extremes
are guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used
to calculate Average Outgoing Quality Level (AOQL).
Note 6:
Junction to ambient thermal resistance with approximately 1 square inch of printed circuit board copper surrounding the leads. Additional copper area will
lower thermal resistance further. See Application Information section in the application note accompanying this datasheet and the thermal model in
LM267X Made
Simple
(version 6.0) software. The value
θ
J−A
for the LLP (LD) package is specifically dependent on PCB trace area, trace material, and the number of layers and
thermal vias. For improved thermal resistance and power dissipation for the LLP package, refer to Application Note AN-1187.
www.national.com
4
NSC [ NATIONAL SEMICONDUCTOR ]
