Datasheet

2
LT3436
3436fa
PARAMETER CONDITION MIN TYP MAX UNITS
Recommended Operating Voltage ● 325V
Maximum Switch Current Limit ● 346 A
Oscillator Frequency 3.3V < V
IN
< 25V ● 640 800 960 kHz
Switch On Voltage Drop I
SW
= 3A ● 330 550 mV
V
IN
Undervoltage Lockout (Note 3) ● 2.47 2.6 2.73 V
V
IN
Supply Current I
SW
= 0A ● 1 1.3 mA
V
IN
Supply Current/I
SW
I
SW
= 3A 15 mA/A
Shutdown Supply Current V
SHDN
= 0V, V
IN
= 25V, V
SW
= 25V 11 25 µA
● 45 µA
Feedback Voltage 3V < V
IN
< 25V, 0.4V < V
C
< 0.9V 1.182 1.2 1.218 V
● 1.176 1.224 V
FB Input Current ● 0 –0.2 – 0.4 µA
FB to V
C
Voltage Gain 0.4V < V
C
< 0.9V 150 350
FB to V
C
Transconductance ∆I
VC
= ±10µA ● 500 850 1300 µMho
V
C
Pin Source Current V
FB
= 1V ● – 85 – 120 –165 µA
V
C
Pin Sink Current V
FB
= 1.4V ● 70 110 165 µA
V
C
Pin to Switch Current Transconductance 4.8 A/V
V
C
Pin Minimum Switching Threshold Duty Cycle = 0% 0.3 V
V
C
Pin 3A I
SW
Threshold 0.9 V
Maximum Switch Duty Cycle V
C
= 1.2V, I
SW
= 350mA 85 90 %
V
C
= 1.2V, I
SW
= 1A ● 80 %
SHDN Threshold Voltage ● 1.28 1.35 1.42 V
SHDN Input Current (Shutting Down) SHDN = 60mV Above Threshold ● –7 –10 –13 µA
SHDN Threshold Current Hysteresis SHDN = 100mV Below Threshold 4 7 10 µA
SYNC Threshold Voltage 1.5 2.2 V
SYNC Input Frequency 1 1.4 MHz
SYNC Pin Resistance I
SYNC
= 1mA 20 kΩ
ABSOLUTE MAXIMUM RATINGS
W
WW
U
ELECTRICAL CHARACTERISTICS
PACKAGE/ORDER INFORMATION
W
U
U
Input Voltage .......................................................... 25V
Switch Voltage ......................................................... 35V
SHDN Pin ............................................................... 25V
FB Pin Current ....................................................... 1mA
SYNC Pin Current .................................................. 1mA
Operating Junction Temperature Range (Note 2)
LT3436E .......................................... – 40°C to 125°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
ORDER PART NUMBER
(Note 1)
T
JMAX
= 125°C, θ
JA
= 45°C/W,
θ
JC(PAD)
= 10°C/W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
3436EFE
FE PART MARKING
LT3436EFE
The ● denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
C
= 0.8V, SHDN, SYNC and switch open unless otherwise noted.
FE PACKAGE
16-LEAD PLASTIC TSSOP
EXPOSED PAD IS GND (PIN 17),
MUST BE SOLDERED TO PCB
1
2
3
4
5
6
7
8
TOP VIEW
16
15
14
13
12
11
10
9
GND
V
IN
SW
SW
GND
GND
NC
GND
GND
NC
SYNC
V
C
FB
SHDN
NC
GND
17