2
LT3433
3433f
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN
Operating Voltage Range ● 460V
V
IN(UVLO)
Undervoltage Lockout Enable Threshold ● 3.4 3.95 V
Undervoltage Lockout Hysteresis 160 mV
V
OUT
Operating Voltage Range ● 3.3 20 V
V
BST
Operating Voltage Range V
BST
< V
SW_H
+ 20V ● 75 V
V
BST
– V
SW_H
● 3.3 20 V
I
VIN
Normal Operation (Notes 2, 3) ● 580 940 µA
Burst Mode Operation V
VC
< 0.6V ● 100 190 µA
Shutdown V
SHDN
< 0.4V ● 10 25 µA
V
BIAS
Internal Supply Output Voltage ● 2.6 2.9 V
Operating Voltage Range ● 20 V
I
VBIAS
Normal Operation ● 660 990 µA
Burst Mode Operation V
VC
< 0.6V 0.1 µA
Shutdown V
SHDN
< 0.4V 0.1 µA
Short-Circuit Current Limit 4.5 mA
R
SWH(ON)
Boost Supply Switch On-Resistance I
SW
= 500mA ● 0.8 1.2 Ω
R
SWL(ON)
Output Supply Switch On-Resistance I
SW
= 500mA ● 0.6 1 Ω
V
SHDN
Shutdown Pin Thresholds Disable ● 0.4 V
Enable
● 1V
I
VBST
/I
SW
Boost Supply Switch Drive Current High Side Switch On, I
SW
= 500mA ● 30 50 mA/A
I
VOUT
/I
SW
Output Supply Switch Drive Current Low Side Switch On, I
SW
= 500mA ● 30 50 mA/A
I
LIM
Switch Current Limit ● 0.5 0.7 0.9 A
Foldback Current Limit V
FB
= 0V 0.35 A
I
SS
Soft-Start Output Current ● 359 µA
(Note 1)
Input Supply (V
IN
) .................................... –0.3V to 60V
Boosted Supply (V
BST
) .............. –0.3V to V
SW_H
+ 30V
(V
BST(MAX)
= 80V)
Internal Supply (V
BIAS
) ............................. –0.3V to 30V
SW_H Switch Voltage.................................. –2V to 60V
SW_L Switch Voltage ............................... –0.3V to 30V
Feedback Voltage (V
FB
)............................... –0.3V to 5V
Burst Enable Pin (V
BURST_EN
) ................... –0.3V to 30V
Shutdown Pin (V
SHDN
) ............................. –0.3V to 60V
Operating Junction Temperature Range (Note 5)
LT3433E (Note 6) ............................ – 40°C to 125°C
LT3433I ........................................... – 40°C to 125°C
Storage Temperature Range ................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ABSOLUTE MAXIMUM RATINGS
W
WW
U
PACKAGE/ORDER INFORMATION
W
U
U
ORDER PART
NUMBER
LT3433EFE
LT3433IFE
FE PART MARKING
3433EFE
3433IFE
T
JMAX
= 125°C, θ
JA
= 40°C/W, θ
JC
= 10°C/W
EXPOSED PAD (PIN 17)
MUST BE SOLDERED TO SGND
The ● denotes specifications that apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
V
IN
= 13.8V, V
FB
= 1.25V, V
OUT
= 5V, V
BURST_EN
= 0V, V
BST
– V
IN
= 5V, unless otherwise noted.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
FE PACKAGE
16-LEAD PLASTIC TSSOP
1
2
3
4
5
6
7
8
TOP VIEW
16
15
14
13
12
11
10
9
SGND
V
BST
SW_H
V
IN
BURST_EN
V
C
V
FB
SGND
SGND
SW_L
PWRGND
V
OUT
V
BIAS
SHDN
SS
SGND
17
