LM3551 Datasheet, PDF (2/15 Pages) National Semiconductor (TI) – 1A White LED Driver with Flash Timeout Protection

Connection Diagram
14 Pin Dual LLP Package
NS Package Number SDA14B
20151202
Pin Descriptions
Pin
9
13
8
10
3
5
12
11
4
14
2
1,7,DAP
Name
V_IN
T/F
SW
OVP
V_C
SD(LM3551)
EN(LM3552)
FTO
SS
FB
FET-T
FET-F
GND
6
AGND
Function
Input Voltage. Input range: 2.7V to 5.5V.
TORCH/FLASH Pin. Low = Torch Mode, High = Flash Mode
Switch Pin
Over Voltage Protection Pin
Compensation network connection. Connected to the output of the voltage error amplifier.
Shutdown pin logic input. High = Shutdown, Low = Enabled
Enable pin logic input. High = Enabled, Low = Shutdown
Flash Timeout. External capacitor determines max. duration allowed flash pulse
Soft Start Pin
Feedback Pin
Torch FET Drain
Flash FET Drain
Ground
Analog Ground. Connect the ground of the compensation components, C_FTO and soft start
cap to AGND. AGND must be connected to the GND pin through a low impedance
connection.
Ordering Information
Order Number
LM3551SD
LM3551SDX
LM3552SD
LM3552SDX
SD / EN
SD
SD
EN
EN
Package Marking
L3551SD
L3551SD
L3552SD
L3552SD
Supplied As
250 units, Tape-and-Reel
3000 units, Tape-and-Reel
250 units, Tape-and-Reel
3000 units, Tape-and-Reel
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