Datasheet

LT3799
3
3799fa
elecTrical characTerisTics
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: The LT3799E is guaranteed to meet performance specifications
from 0°C to 125°C junction temperature. Specifications over the –40°C
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 18V, unless otherwise noted.
PARAMETER CONDITIONS MIN TYP MAX UNITS
FB Pin Bias Current (Note 3), FB = 1V 100 600 nA
CTRL1/CTRL2/CTRL3 Pin Bias Current CTRL/CTRL2/CTRL3 = 1V ±25 nA
Maximum SENSE Current Limit Threshold 96 100 106 mV
SENSE Input Bias Current Current Out of Pin, SENSE = 0V 15 µA
Current Loop Voltage Gain ∆V
CTRL
/ ∆V
SENSE
, 1000pF Cap from COMP
+
to COMP
–
21 V/V
CT Pin Charge Current 10 µA
CT Pin Discharge Current 200 nA
CT Pin Low Threshold Falling Threshold 240 mV
CT Pin High Threshold Rising Threshold 1.25 V
CT Pin Low Hysteresis 100 mV
FB Pin High Threshold 1.22 1.25 1.29 V
DCM Current Turn-On Threshold Current Out of Pin 45 µA
Maximum Oscillator Frequency COMP
+
= 1.2V, V
IN_SENSE
= 1V 300 kHz
Minimum Oscillator Frequency COMP
+
= 0V, V
IN_SENSE
25 kHz
Back-Up Oscillator Frequency 20 kHz
Linear Regulator
INTV
CC
Regulation Voltage 9.8 10 10.4 V
Dropout (V
IN
– INTV
CC
) INTV
CC
= –10mA; Below V
IN
Turn-Off Voltage 750 1150 mV
Current Limit Below Undervoltage Threshold 15 25 mA
Current Limit Above Undervoltage Threshold 80 120 mA
Gate Driver
t
r
GATE Driver Output Rise Time C
L
= 3300pF, 10% to 90% 20 ns
t
f
GATE Driver Output Fall Time C
L
= 3300pF, 90% to 10% 20 ns
GATE Output Low (V
OL
) 0.05 V
GATE Output High (V
OH
) INTV
CC
– 0.05
V
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT3799I is guaranteed to meet performance specifications from –40°C to
125°C operating junction temperature.
Note 3: Current flows out of the FB pin.