LTC3855 LINER [Linear Technology], LTC3855 Datasheet - Page 4

• Manufacturer Part Number: LTC3855
• Description: Dual, Fast, Accurate Step-Down DC/DC Controller
• Manufacturer: LINER [Linear Technology]

LTC3838
ELECTRICAL CHARACTERISTICS
SYMBOL
Current Sensing
V
V
I
I
Start-Up and Shutdown
V
I
UVLO
I
Frequency and Clock Synchronization
V
V
R
Gate Drivers
R
R
R
R
t
t
4
junction temperature range, otherwise specifications are at T
SENSE1,2
SENSE1,2
RUN1,2
TRACK/SS1,2
D(TG/BG)1,2
D(BG/TG)1,2
SENSE(MAX)1,2
SENSE(MIN)1,2
RUN1,2
PLLIN(H)
PLLIN(L)
MODE/PLLIN
TG(UP)1,2
TG(DOWN)1,2
BG(UP)1,2
BG(DOWN)1,2
+
–
PARAMETER
Maximum Valley Current Sense Threshold
(V
Minimum Valley Current Sense Threshold
(V
(Forced Continuous Mode)
SENSE1,2
SENSE1,2
(Internal 500k Resistor to SGND)
RUN Pin On Threshold
RUN Pin On Hysteresis
RUN Pin Pull-Up Current when Off
RUN Pin Pull-Up Current Hysteresis
INTV
Soft-Start Pull-Up Current
Clock Output Frequency
(Steady-State Switching Frequency)
Channel 2 Phase (Relative to Channel 1)
CLKOUT Phase (Relative to Channel 1)
Clock Input High Level Into MODE/PLLIN
Clock Input Low Level Into MODE/PLLIN
MODE/PLLIN Input DC Resistance
TG Driver Pull-Up On Resistance
TG Driver Pull-Down On Resistance
BG Driver Pull-Up On Resistance
BG Driver Pull-Down On Resistance
Top Gate Off to Bottom Gate On Delay Time (Note 6)
Bottom Gate Off to Top Gate On Delay Time (Note 6)
SENSE1,2
SENSE1,2
CC
Undervoltage Lockout
+
–
+
+
Pins Input Bias Current
Pins Input Bias Current
– V
– V
SENSE1,2
SENSE1,2
–
–
)
)
CONDITIONS
V
V
V
V
V
V
V
V
V
V
V
V
RUN1,2 = SGND
I
INTV
INTV
0V < TRACK/SS1,2 < 0.6V
R
R
R
PHASMD = SGND
PHASMD = Floating
PHASMD = INTV
PHASMD = SGND
PHASMD = Floating
PHASMD = INTV
With Respect to SGND
TG High
TG Low
BG High
BG Low
RUN1,2(HYS)
RNG
RNG
RNG
RNG
RNG
RNG
SENSE
SENSE
SENSE
SENSE
RUN1,2
RUN1,2
T
T
T
= 205k
= 80.6k
= 18.2k
The
CC
CC
= 2V, V
= 0V, V
= INTV
= 2V, V
= 0V, V
= INTV
+
+
–
–
A
Falling
Rising
Rising
Falling from On Threshold
= 0.6V
= 5V
= 0.6V
= 5V
l
= 25°C. V
denotes the specifications which apply over the specified operating
= I
FB
FB
CC
FB
FB
CC
, V
, V
RUN1,2(ON)
= 0.57V, V
= 0.57V, V
= 0.63V, V
= 0.63V, V
CC
CC
FB
FB
= 0.57V, V
= 0.63V, V
IN
= 15V unless otherwise noted (Note 3).
SENSE
SENSE
SENSE
SENSE
– I
RUN1,2(OFF)
SENSE
SENSE
–
–
–
–
= 2.5V
= 2.5V
= 2.5V
= 2.5V
–
–
= 2.5V
= 2.5V
l
l
l
l
l
l
MIN
450
1.1
3.3
80
21
39
2
2000
TYP
100
–50
–15
–25
100
200
500
180
180
240
120
600
1.2
1.2
1.2
3.7
4.2
2.5
1.2
2.5
0.8
30
50
±5
10
60
90
20
15
1
5
1
MAX
120
±50
550
1.3
4.5
0.5
40
61
±2
UNITS
3838fa
Deg
Deg
Deg
Deg
Deg
Deg
kHz
kHz
kHz
mV
mV
mV
mV
mV
mV
mV
kΩ
nA
μA
μA
μA
μA
μA
μA
ns
ns
Ω
Ω
Ω
Ω
V
V
V
V
V