Datasheet

LT3476
3
3476fb
PARAMETER CONDITIONS MIN TYP MAX UNITS
REF Line Regulation 2.8V ≤ V
IN
≤ 16V 0.003 %/V
Quiescent Current in Shutdown SHDN = 0V
0.1 10 µA
Quiescent Current Idle PWM1-4 = 0V 5.5 mA
Quiescent Current Active (Not Switching) VC1-4 = 0V 22 30 mA
Switching Frequency R
T
= 8.25k
R
T
= 21k
R
T
= 140k
1700
850
160
2000
1000
200
2300
1150
240
kHz
kHz
kHz
Nominal RT Pin Voltage 1.26 V
Maximum Duty Cycle R
T
= 8.25k (2MHz)
R
T
= 21k (1MHz)
R
T
= 140k (200kHz)
84
76
90
98
%
%
%
V
ADJ1-4
Input Bias Current Current Out of Pin –10 20 100 nA
VC1-4 Idle Input Bias Current PWM1-4 = 0V –20 0 20 nA
EAMP GM (∆I
VC
/∆V
CAP-LED
) 210 µS
VC Output Impedance 3 MΩ
SW1-4 Current Limit Static Test 1.5 2 2.5 A
SW1-4 V
CESAT
I
SW
= 1.3A to GND 350 mV
SW1-4 Leakage Current SHDN = 0V 0.1 5 µA
CAP1-4 Overvoltage Protect Threshold 33.5 35 V
CAP1-4/LED1-4 Idle Input Bias Current PWM1-4 < 0.4V, CAP = LED = 5V 100 nA
CAP1-4/LED1-4 Input Bias Current CAP = LED = 5V 70 µA
SHDN Input Low Voltage
l
0.4 V
SHDN Input High Voltage
l
1.5 V
SHDN Pin Current 16 30 µA
PWM1-4 Input Low Voltage
l
0.4 V
PWM1-4 Input High Voltage
l
1.5 V
PWM1-4 Pin Current 50 100 µA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 3: The LT3476E is guaranteed to meet specifications from 0°Cto
85°C junction temperature. Specifications over the –40°Cto85°C
operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT3476I is guaranteed to meet performance specifications over the –40°C
to 125°C operating junction temperature range.
electricAl chArActeristics
The l denotes the specifications which apply over the full operating
temperature range, (Note 3) otherwise specifications are at T
A
= 25°C. SW1-4 = 5V, V
IN
= 3.3V, SHDN = 3.3V, R
T
= 21k to GND,
PWM1-4 = 3.3V, V
ADJ1-4
= REF, CAP1-4 = 5V, unless otherwise noted.