ltc3851-1 Linear Technology Corporation, ltc3851-1 Datasheet - Page 3

• Manufacturer Part Number: ltc3851-1
• Description: Synchronous Step-down Switching Regulator Controller
• Manufacturer: Linear Technology Corporation

ELECTRICAL CHARACTERISTICS
junction temperature range, otherwise specifi cations are at T
SYMBOL
Main Control Loops
V
V
I
V
V
g
g
I
UVLO
UVLO Hys
V
I
I
V
V
V
TG R
TG R
BG R
BG R
TG t
TG t
BG tr
BG tf
TG/BG t
BG/TG t
t
INTV
V
V
FB
Q
SENSE
TK/SS
ON(MIN)
m
m
IN
FB
REFLNREG
LOADREG
OVL
RUN
RUNHYS
SENSE(MAX)
INTVCC
LDO
GBW
r
f
CC
UP
DOWN
UP
DOWN
INT
Linear Regulator
1D
2D
PARAMETER
Input Operating Voltage Range
Regulated Feedback Voltage
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
Transconductance Amplifi er g
Transconductance Amp Gain Bandwidth
Input DC Supply Current
Undervoltage Lockout on INTV
UVLO Hysteresis
Feedback Overvoltage Lockout
SENSE Pins Total Current
Soft-Start Charge Current
RUN Pin On Threshold
RUN Pin On Hysteresis
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
BG Transition 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
Normal Mode
Shutdown
Rise Time
Fall Time
Rise Time
Fall Time
CC
Load Regulation
CC
Voltage
m
CC
CONDITIONS
I
(Note 4)
V
(Note 4)
Measured in Servo Loop,
ΔI
(Note 4)
Measured in Servo Loop,
ΔI
I
I
(Note 5)
V
V
V
Measured at V
V
V
V
TG High
TG Low
BG High
BG Low
(Note 6)
C
C
(Note 6)
C
C
C
C
(Note 7)
6V < V
I
TH
TH
TH
CC
TK/SS
IN
OUT
RUN
INTVCC
RUN
FB
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
TH
TH
= 1.2V (Note 4)
= 1.2V, Sink/Source = 5μA (Note 4)
= 1.2V
= 0mA to 50mA
= 6V to 38V (Note 4)
= 0.7V, V
= 1.2V to 0.7V
= 1.2V to 1.6V
= 5V
= 0V
Rising
IN
= 3300pF
= 3300pF
= 3300pF
= 3300pF
= 3300pF Each Driver
= 3300pF Each Driver
= 0V
Ramping Down
< 38V
The
A
SENSE
= 25°C. V
l
FB
denotes the specifi cations which apply over the full operating
= 3.3V
IN
= 15V, V
RUN
= 5V unless otherwise noted.
l
l
l
l
l
l
0.792
0.86
1.10
MIN
0.6
4.8
40
4
0.800
0.002
–0.01
LTC3851-1
0.01
3.25
0.88
1.22
TYP
–10
130
0.4
2.6
1.5
2.4
1.1
0.5
20
±1
50
25
25
25
25
30
30
90
2
3
1
1
5
0.808
MAX
0.02
–0.1
0.90
1.35
–50
0.1
5.2
38
35
±2
65
2
UNITS
mmho
38511f
3
MHz
%/V
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