LTC3854 LINER [Linear Technology], LTC3854 Datasheet - Page 3

• Manufacturer Part Number: LTC3854
• Description: Small Footprint, Wide VIN Range Synchronous Step-Down DC/DC Controller
• Manufacturer: LINER [Linear Technology]

elecTrical characTerisTics
temperature range, otherwise specifications are at T
SYMBOL
Main Control Loop
V
V
I
V
V
gm
gm
I
UVLO
UVLO
V
I
DF
I
V
V
V
TG R
TG R
BG R
BG R
TG t
TG t
BG t
BG t
TG/BG t
BG/TG t
t
INTV
V
V
Oscillator
f
FB
Q
SENSE
RUN/SS
ON(MIN)
SW
IN
FB
REFLNREG
LOADREG
OVL
RUN/SS_SD
RUN/SS_ON
SENSE(MAX)
INTVCC
LDO
MAX
GBW
r
f
r
f
CC
UP
DOWN
UP
DOWN
INT
HYST
Linear Regulator
1D
2D
PARAMETER
Operating Input Voltage Range
Regulated Feedback Voltage
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
Transconductance Amplifier gm
Transconductance Amplifier GBW
Input DC Supply Current
Normal Mode
Shutdown
Undervoltage Lockout
Undervoltage Lockout Hysteresis
Feedback Overvoltage Lockout
Sense Pins Source Current
Maximum Duty Factor
Soft-Start Charge Current
Shutdown Threshold
Soft-Start Threshold
Maximum Current Sense Threshold
TG Driver Pull-Up On Resistance
TG Driver Pull-Down On Resistance
BG Driver Pull-Up On Resistance
BG Driver Pull-down On Resistance
TG Transition Time:
Rise Time
Fall Time
BG Transition Time:
Rise Time
Fall Time
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
Minimum On-Time
Internal V
INTV
Switching Frequency
CC
Load Regulation
CC
Voltage
CONDITIONS
(Note 4); ITH Voltage = 1.2V
(Note 4)
V
(Note 4) Measured in Servo Loop;
∆
Measured in Servo Loop;
∆
ITH = 1.2V; Sink/Source = 5µA (Note 4)
ITH = 1.2V; (Guaranteed by Design)
(Note 5)
RUN = 0V
V
V
Measured at FB
V
In Dropout
RUN/SS = 0V
RUN/SS Pin Must be Taken Below this Value to
Reset Part (or Put into Shutdown Mode)
Soft-Start Mode
FB = 0.7V, V
TG High
TG Low
BG High
BG Low
(Note 6)
C
C
(Note 6)
C
C
C
C
(Note 7)
6V < V
I
CC
A
IN
IN
IN
SENSE
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
ITH
ITH
= 25°C. V
= 0 to 20mA
= 6V to 38V (Note 4)
Ramping Down; Measured at INTV
Ramping Down then Up; Measured at INTV
Voltage = 0.7V to 1.2V
Voltage = 1.2V to 2V
= 3300pF
= 3300pF
= 3300pF
= 3300pF
= 3300pF Each Driver
= 3300pF Each Driver
IN
– = V
The
< 38V
SENSE
SENSE
l
IN
denotes the specifications which apply over the full operating
= 15V, V
– = 3.3V, V
+ = 3.3V
RUN
IN
= 5V, unless otherwise noted.
= 6V
CC
CC
l
l
l
l
l
0.792
0.86
MIN
360
4.5
3.0
0.6
4.8
97
40
0.002
–0.1
0.88
1.25
TYP
350
±0.5
400
0.8
0.1
2.0
3.5
0.4
1.2
2.5
1.2
2.5
2.1
5.0
0.2
±5
10
98
50
25
25
25
25
30
30
75
3
2
LTC3854
0.808
MAX
0.02
–0.5
0.90
±50
440
0.5
2.0
5.2
1.0
38
25
±1
65
3
UNITS
mmho
3854fa

MHz
%/V
kHz
mA
mV
mV
nA
µA
µA
µA
ns
ns
ns
ns
ns
ns
ns
%
%
%
%
Ω
Ω
Ω
Ω
V
V
V
V
V
V
V