Datasheet

LTC3862
3
3862fc
For more information www.linear.com/LTC3862
elecTrical characTerisTics
(Notes 2, 3) The l denotes the specifications which apply over the specified
operating junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, RUN = 2V and SS = open, unless
otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Supply Input and INTV
CC
Linear Regulator
V
IN
V
IN
Supply Voltage Range 4 36 V
I
VIN
V
IN
Supply Current
Normal Mode, No Switching
Shutdown
(Note 5)
V
RUN
= 0V
l
l
1.8
30
3.0
80
mA
µA
INTV
CC
LDO Regulator Output Voltage 4.8 5.0 5.2 V
dV
INTVCC(LINE)
Line Regulation 6V < V
IN
< 36V 0.002 0.02 %/V
dV
INTVCC(LOAD)
Load Regulation Load = 0mA to 20mA –2 %
V
UVLO
INTV
CC
UV
+
Voltage Rising INTV
CC
3.3 V
INTV
CC
UV
–
Voltage Falling INTV
CC
2.9 V
3V8 LDO Regulator Output Voltage 3.8 V
Switcher Control Loop
V
FB
Reference Voltage V
ITH
= 0.8V (Note 6) E-Grade (Note 3)
I-Grade and H-Grade (Note 3)
l
l
1.210
1.199
1.223
1.223
1.235
1.248
V
V
dV
FB
/dV
IN
Feedback Voltage V
IN
Line Regulation V
IN
= 4V to 36V (Note 6) ±0.002 0.01 %/V
dV
FB
/dV
ITH
Feedback Voltage Load Regulation V
ITH
= 0.5V to 1.2V (Note 6) 0.01 0.1 %
g
m
Transconductance Amplifier Gain V
ITH
= 0.8V (Note 6), ITH Pin Load = ±5µA 660 µMho
f
0dB
Error Amplifier Unity-Gain Crossover
Frequency
(Note 7) 1.8 MHz
V
ITH
Error Amplifier Maximum Output Voltage
(Internally Clamped)
V
FB
= 1V, No Load 2.7 V
Error Amplifier Minimum Output Voltage V
FB
= 1.5V, No Load 50 mV
I
ITH
Error Amplifier Output Source Current –30 µA
Error Amplifier Output Sink Current 30 µA
I
FB
Error Amplifier Input Bias Currents (Note 6) –50 –200 nA
V
ITH(PSKIP)
Pulse Skip Mode Operation ITH Pin Voltage Rising ITH Voltage (Note 6)
Hysteresis
0.275
25
V
mV
I
SENSE(ON)
SENSE Pin Current 0.01 2 µA
V
SENSE(MAX)
Maximum Current Sense Input Threshold V
SLOPE
= Float, Low Duty Cycle
(Note 3)
l
65
60
75
75
85
90
mV
mV
V
SENSE(MATCH)
CH1 to CH2 Maximum Current Sense
Threshold Matching
V
SLOPE
= Float, Low Duty Cycle (Note 3)
(V
SENSE1
– V
SENSE2
)
l
–10 10 mV
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 kΩ
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