LT3798
3
3798fa
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 LT3798E is guaranteed to meet specified performance from
0°C to 125°C junction temperature. Specification over the –40°C and
125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 18V, INTV
CC
= 11V, unless otherwise noted.
LT3798I is guaranteed to meet specified performance from –40°C to 125°C
operating junction temperature range. The LT3798H is guaranteed to meet
performance specifications over the –40°C to 150°C operating junction
temperature range. The LT3798MP is guaranteed to meet performance
specifications over the –55°C to 150°C operating junction temperature
range. High junction temperatures degrade operating lifetimes. Operating
lifetime is derated for junction temperatures greater than 125°C.
Note 3: Current flows out of the FB pin.
PARAMETER CONDITIONS MIN TYP MAX UNITS
SENSE Current Limit Threshold V
IN_SENSE
= 150µA 96 102 107 mV
Minimum SENSE Current Limit Threshold V
IN_SENSE
= 34µA 14 mV
Minimum SENSE Current Limit Threshold V
IN_SENSE
= 21µA 4 mV
SENSE Input Bias Current Current Out of Pin, SENSE = 0V 15 µA
FB Voltage
l
1.22 1.25 1.28 V
FB voltage Line Regulation 10V < V
IN
< 35V 0.01 0.03 %/V
FB Pin Bias Current (Note 3), FB = 1V 4.05 4.25 4.4 µA
FB Error Amplifier Voltage Gain ΔV
VC
/ΔV
FB
, CTRL1=1V, CTRL2=2V, CTRL3=2V 180 V/V
FB Error Amplifier Transconductance ΔI = 5µA 170 UMHOS
Current Error Amplifier Voltage Gain
ΔV
COMP
+/ΔV
COMP
–, CTRL1 = 1V, CTRL2 = 2V, CTRL3 = 2V 100 V/V
Current Error Amplifier Transconductance
ΔI = 5µA 50 UMHOS
Current Loop Voltage Gain ΔV
CTRL
/ΔV
SENSE
,1000pF Cap from COMP
+
to COMP
–
21 V/V
DCM Current Turn-On Threshold Current Out of Pin 80 µA
Maximum Oscillator Frequency COMP
+
= 0.95V, V
IN_SENSE
=
150µA 150 kHz
Minimum Oscillator Frequency COMP
+
= 0V, V
FB
<V
OVP
4 kHz
Minimum Oscillator Frequency COMP
+
= 0V, V
FB
>V
OVP
0.5 kHz
Backup Oscillator Frequency 20 kHz
Linear Regulator
INTV
CC
Regulation Voltage No Load 9.8 10 10.4 V
Dropout (V
IN
-INTV
CC
) I
INTVCC
= –10mA, V
IN
= 10V 500 900 mV
Current Limit Below Undervoltage Threshold 12 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% 18 ns
t
f
GATE Driver Output Fall Time C
L
= 3300pF, 90% to 10% 18 ns
GATE Output Low (V
OL
) 0.01 V
GATE Output High (V
OH
) INTV
CC
-
50mV
V
