LTM8042/LTM8042-1
3
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For more information www.linear.com/LTM8042
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: Absolute maximum voltage at V
CC
, RUN, PWM, TGEN, BSTIN/
BKLED
–
pins is 40V for non-repetitive one second transients and 30V for
continuous operation.
Note 3: The LTM8042E/LTM8042E-1 are guaranteed to meet performance
specifications from 0°C to 125°C ambient. Specifications over the full
–40°C to 125°C internal operating temperature range are assured by
design, characterization and correlation with statistical process controls.
The l denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V, buck mode with 4Ω load.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
CC(MIN)
Minimum Input DC Voltage
l
3 V
I
LED
LTM8042 LED Current
LTM8042-1 LED Current
CTL Open
R
CTL
= 6.81k
CTL Open
R
CTL
= 6.81k
0.9
0.45
0.34
0.17
0.5
1.05
0.55
0.39
0.20
A
A
A
A
V
CLAMP
Open LED Clamp Voltage Boost Mode, LED
+
Open 36 V
∆I
OUT
/I
OUT
Output Current Line Regulation LTM8042, 6V < BSTOUT/BKIN < 30V
LTM8042-1, 6V < BSTOUT/BKIN < 30V
0.5
0.5
%
%
I
QVCC
V
CC
Supply Current PWM = 0V
RUN = 0V
4.2
0.1
1
mA
µA
f
SW
Switching Frequency RT = 90.9k
RT = 22.1k
RT = 6.04k
0.22
0.68
1.7
0.25
0.8
2
0.27
0.92
2.3
MHz
MHz
MHz
I
SS
Soft-Start Pin Current SS = 0.5V, Out of Pin 6 9 12 µA
f
SYNC
Synchronization Frequency Range 0.3 2.5 MHz
I
SYNC
SYNC Pull-Down Current (Into the Pin) V
SYNC
= 2V 60 µA
V
SYNC(IL)
SYNC Input Low 0.4 V
V
SYNC(IH)
SYNC Input High 1.5 V
I
CTL
CTL Input Bias Current CTL = 0V, Flows Out of Pin 100 µA
V
RUN(IH)
RUN Input Voltage High 1.5 V
V
RUN(IL)
RUN Input Voltage Low 0.4 V
I
RUN
RUN Pin Bias Current 60 100 µA
V
PWM(IH)
PWM Input Voltage High 1.5 V
V
PWM(IL)
PWM Input Voltage Low 0.4 V
I
PWM
PWM Pin Bias Current 60 120 µA
V
TG(OH)
TG Output High Voltage Relative to LED
+
, 100k from LED
+
to TG 0 V
V
TG(OL)
TG Output Low Voltage Relative to LED
+
, 100k from LED
+
to TG –7 V
V
TGEN(IH)
TGEN Input Voltage High PWM = 0V 1.5 V
V
TGEN(IL)
TGEN Input Voltage Low 0.4 V
I
TGEN
TGEN Pin Bias Current 100 200 µA
The LTM8042I/LTM8042I-1 are guaranteed to meet specifications over
the full –40°C to 125°C internal operating temperature range. Note that
the maximum internal temperature is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
resistance and other environmental factors.
Note 4: This device includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed the maximum internal operating temperature
when overtemperature protection is active. Continuous operation above
the specified maximum operating junction temperature may impair device
reliability.
