LM3481 Datasheet, PDF (3/22 Pages) National Semiconductor (TI) – High Efficiency Low-Side N-Channel Controller for Switching Regulators

Absolute Maximum Ratings (Note 1)
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V_IN pin Voltage
FB Pin Voltage
FA/SYNC/SD Pin Voltage
COMP Pin Voltage
UVLO Pin Voltage
V_CC Pin Voltage
DR Pin Voltage
I_SEN Pin Voltage
Peak Driver Output Current
Power Dissipation
-0.4V to 50V
-0.4V to 6V
-0.4V to 6V
-0.4V to 6V
-0.4V to 6V
-0.4V to 6V
-0.4V to 6V
–0.4V to 600 mV
1.0A
Internally Limited
Storage Temperature Range
Junction Temperature
ESD Susceptibilty
 Human Body Model (Note 2)
Lead Temperature
MM Package
Vapor Phase (60 sec.)
Infared (15 sec.)
−65°C to +150°C
+150°C
2 kV
215°C
220°C
Operating Ratings (Note 1)
Supply Voltage
Junction Temperature Range
Switching Frequency
Range
2.97V to 48V
−40°C to +125°C
100 kHz to 1 MHz
Electrical Characteristics
V_IN=12V, R_FA=40 kΩ unless otherwise indicated under the Conditions column. Typicals and limits appearing in plain type apply
for T_J = 25°C. Limits appearing in boldface type apply over the full Operating Temperature Range (-40°C to 125°C). Datasheet
min/max specification limits are guaranteed by design, test, or statistical analysis. (Notes 3, 4)
Symbol
Parameter
Conditions
Min
Typical
Max
Units
V_FB
ΔV_LINE
Feedback Voltage
Feedback Voltage Line
Regulation
V_COMP = 1.4V,
2.97 ≤ V_IN ≤ 48V
2.97 ≤ V_IN ≤ 48V
1.256
1.275
1.294
V
0.003
%/V
ΔV_LOAD
Output Voltage Load
Regulation
I_EAO Source/Sink
±0.5
%/V
V_UVLOSEN
Undervoltage Lockout
Reference Voltage
V_UVLO Ramping Down
1.345
1.430
1.517
V
I_UVLO
V_UVLOSD
I_COMP
V_COMP
f_nom
UVLO Source Current
UVLO Shutdown Voltage
COMP pin Current Sink
Nominal Switching
Frequency
Enabled
V_FB = 0V
V_FB = 1.275V
R_FA = 40 kΩ
3
5
6
µA
0.7
V
640
µA
1
V
406
475
550
kHz
Threshold for
V_sync-HI
Synchronization on
Synchronization Voltage
Rising
1.4
V
FA/SYNC/SD pin
V_sync-LOW
Threshold for
Synchronization on
FA/SYNC/SD pin
Synchronization Voltage
Falling
0.7
V
R_{DS1 (ON)}
Driver Switch On
Resistance (top)
I_DR = 0.2A, V_IN= 5V
4
Ω
R_{DS2 (ON)}
Driver Switch On
Resistance (bottom)
I_DR = 0.2A
2
Ω
V_{DR (max)}
D_max
t_min (on)
I_SUPPLY
I_Q
Maximum Drive Voltage
Swing(Note 6)
Maximum Duty Cycle
V_IN < 6V
V_IN ≥ 6V
Minimum On Time
Supply Current (switching) (Note 8)
Quiescent Current in
Shutdown Mode
V_FA/SYNC/SD = 3V(Note 9),
V_IN = 12V
V_FA/SYNC/SD = 3V(Note 9),
V_IN = 5V
V_IN
V
6
85
%
250
ns
3.7
5.0
mA
9
15
µA
5
10
3
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