LM3551 Datasheet, PDF (3/15 Pages) National Semiconductor (TI) – 1A White LED Driver with Flash Timeout Protection

Absolute Maximum Ratings (Notes 1, 2)
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V_IN pin: Voltage to GND
SW pin: Voltage to GND
7.5V
21V
FB pin: Voltage to GND
7V
V_C pin: Voltage to GND
SD,T/F pins: Voltage to GND
1.26V ± 0.3V
7.5V
FET-T, FET-F: Voltage to GND
6V
Continuous Power Dissipation (Note 3) Internally Limited
Junction Temperature (T_{J-MAX )}
Storage Temperature Range
150˚C
-65˚C to +150
Maximum Lead Temperature
(Soldering)
(Note 4)
ESD Rating(Note 5)
Human Body Model
2.0kV
Operating Ratings(Notes 1, 2)
Input Voltage Range
SW Voltage Max. (Note 6)
Junction Temperature (T_J)
Range
Ambient Temperature (T_A)
Range (Note 7)
2.7V to 5.5V
20V
-40˚C to +110˚C
-40˚C to +85˚C
Thermal Properties
Junction-to-Ambient Thermal
Resistance (θ_JA), SDA14B
Package (Note 8)
37.3˚C/W
ESD Caution Notice National Semiconductor recommends that all integrated circuits be handled with appropri-
ate ESD precautions. Failure to observe proper ESD handling techniques can result in damage to the device.
Electrical Characteristics(Notes 2, 9)
Limits in standard typeface are for T_J = +25˚ C. Limits in boldface type apply over the full operating junction temperature range
(-40˚C ≤ T_J ≤ +110˚C). Unless otherwise noted, specifications apply to the LM3551 and LM3552 Typical Application Circuit (pg.
1) with: V_IN = 3.6V, V(SD) = 0V for LM3551 and V(EN) = V_IN for LM3552, I_LOAD = 0A (Note 10)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
I_Q
Quiescent Current
I_SD
Shutdown Current
FB = V_IN (Not Switching)
V(SD) = V_IN
LM3551
V(EN) = 0V
LM3552
1.47
2.0
mA
2.55
5.0
µA
0.1
2.3
I_{CL(Note 11)}
V_FB
I_{FB(Note 13)}
g_m
Switch Current Limit
Feedback Voltage
Feedback Pin Bias Current
Error Amp
Transconductance
V_IN = 3.0V(Note 12)
∆I = 5µA
1.2285
2.1
1.265
50
135
1.2915
A
V
nA
µmho
A_V
D_MAX
f_sw
I_SDPIN
Error Amp Voltage Gain
Maximum Duty Cycle
Switching Frequency
Shutdown Pin Current
(LM3551)
V_SD = 0V
135
V/V
92.5
%
0.9
1.25
1.6
MHz
3.0
6
µA
I_ENPIN
Enable Pin Current
(LM3552)
V_EN = 3.6V
3.0
6
µA
I_T/FPIN
I_L-SW
R_DSON-SW
I_L-T
R_DSON-T
I_L-F
R_DSON-F
Th_SD/EN
T/F Pin Current
SW Pin Leakage Current
SW Pin R_DSON
FET-T Leakage Current
FET-T R_DSON
FET-F Leakage Current
FET-F R_DSON
Shutdown/Enable Pin
Threshold
V_T/F = 0V
V_T/F = V_IN
V_L-SW = 20V
I_SW = 0.5A
Output High
Output Low
26
nA
22
0.07
8
µA
0.165
Ω
0.1
µA
0.98
Ω
0.1
µA
0.36
Ω
1.2
V
0.3
3
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