Datasheet

LTC3862-1
4
38621f
ELECTRICAL CHARACTERISTICS
(Notes 2, 3) The l denotes the specifi cations which apply over the full
operating temperature range, otherwise specifi cations are at T
A
= 25°C. V
IN
= 12V, RUN = 2V and SS = open, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
RUN/Soft-Start
I
RUN
RUN Source Current V
RUN
= 0V
V
RUN
= 1.5V
–0.5
–5
µA
µA
V
RUN
High Level RUN Channel Enable Threshold 1.22 V
V
RUNHYS
RUN Threshold Hysteresis 80 mV
I
SS
SS Pull-Up Current V
SS
= 0V –5 µA
R
SS
SS Pull-Down Resistance V
RUN
= 0V 10 k
Oscillator
f
OSC
Oscillator Frequency R
FREQ
= 45.6k
R
FREQ
= 45.6k
l
280
260
300
300
320
340
kHz
kHz
Oscillator Frequency Range
l
75 500 kHz
V
FREQ
Nominal FREQ Pin Voltage R
FREQ
= 45.6k 1.223 V
f
SYNC
SYNC Minimum Input Frequency V
SYNC
= External Clock
l
50 kHz
SYNC Maximum Input Frequency V
SYNC
= External Clock
l
650 kHz
V
SYNC
SYNC Input Threshold Rising Threshold 1.5 V
I
PLLFLTR
Phase Detector Sourcing Output Current f
SYNC
> f
OSC
–15 µA
Phase Detector Sinking Output Current f
SYNC
< f
OSC
15 µA
CH1-CH2 Channel 1 to Channel 2 Phase Relationship V
PHASEMODE
= 0V
V
PHASEMODE
= Float
V
PHASEMODE
= 3V8
180
180
120
Deg
Deg
Deg
CH1-CLKOUT Channel 1 to CLKOUT Phase Relationship V
PHASEMODE
= 0V
V
PHASEMODE
= Float
V
PHASEMODE
= 3V8
90
60
240
Deg
Deg
Deg
D
MAX
Maximum Duty Cycle V
DMAX
= 0V
V
DMAX
= Float
V
DMAX
= 3V8
96
84
75
%
%
%
t
ON(MIN)1
Minimum On-Time V
BLANK
= 0V (Note 8) 210 ns
t
ON(MIN)2
Minimum On-Time V
BLANK
= Float (Note 8) 290 ns
t
ON(MIN)3
Minimum On-Time V
BLANK
= 3V8 (Note 8) 375 ns
Gate Driver
R
DS(ON)
Driver Pull-Up R
DS(ON)
3
Driver Pull-Down R
DS(ON)
0.9 
Overvoltage
V
FB(OV)
V
FB
, Overvoltage Lockout Threshold V
FB(OV)
– V
FB(NOM)
in Percent 8 10 12 %
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: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specifi ed.
Note 3: The LTC3862E-1 is guaranted to meet performance specifi cations
from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3862I-1 is guaranteed over the
full –40°C to 125°C operating temperature range and the LTC3862H-1 is
guaranteed over the full –40°C to 150°C operating temperature range.
High junction temperatures degrade operating lifetimes. Operating lifetime
is derated at junction temperatures greater than 125°C.
Note 4: This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. Continuous
operation above the specifi ed maximum operating junction temperature
may impair device reliability.
Note 5: Supply current in normal operation is dominated by the current
needed to charge the external MOSFET gates. This current will vary with
supply voltage and the external MOSFETs used.
Note 6: The IC is tested in a feedback loop that adjusts V
FB
to achieve a
specifi ed error amplifi er output voltage.
Note 7: Guaranteed by design, not subject to test.
Note 8: The minimum on-time condition is specifi ed for an inductor peak-
to-peak ripple current = 30% (see Minimum On-Time Considerations in the
Applications Information section).