LTC3854_15 Datasheet, PDF (3/28 Pages) Linear Technology – Small Footprint, Wide VIN Range Synchronous Step-Down DC/DC Controller

LTC3854
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 15V, V_RUN = 5V, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
Main Control Loop
V_IN
Operating Input Voltage Range
4.5
38
V_FB
I_FB
V_REFLNREG
V_LOADREG
Regulated Feedback Voltage
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
gm
Transconductance Amplifier gm
(Note 4); ITH Voltage = 1.2V
(Note 4)
V_IN = 6V to 38V (Note 4)
(Note 4) Measured in Servo Loop;
∆_ITH Voltage = 0.7V to 1.2V
Measured in Servo Loop;
∆_ITH Voltage = 1.2V to 2V
ITH = 1.2V; Sink/Source = 5µA (Note 4)
l 0.792
l
l
0.8
±5
0.002
0.1
–0.1
0.808
±50
0.02
0.5
–0.5
2.0
gm_GBW
I_Q
Transconductance Amplifier GBW
Input DC Supply Current
Normal Mode
Shutdown
ITH = 1.2V; (Guaranteed by Design)
(Note 5)
RUN = 0V
3
2
3
10
25
UVLO
UVLO_HYST
V_OVL
I_SENSE
Undervoltage Lockout
Undervoltage Lockout Hysteresis
Feedback Overvoltage Lockout
Sense Pins Source Current
V_IN Ramping Down; Measured at INTV_CC
l 3.0
3.5
V_IN Ramping Down then Up; Measured at INTV_CC
350
Measured at FB
l 0.86 0.88 0.90
V_SENSE– = V_SENSE+ = 3.3V
±0.5
±1
DF_MAX
Maximum Duty Factor
In Dropout
97
98
I_RUN/SS
V_{RUN/SS_SD}
Soft-Start Charge Current
Shutdown Threshold
RUN/SS = 0V
RUN/SS Pin Must be Taken Below this Value to
Reset Part (or Put into Shutdown Mode)
0.6
1.25
2.0
0.4
V_{RUN/SS_ON}
V_SENSE(MAX)
TG R_UP
TG R_DOWN
Soft-Start Threshold
Maximum Current Sense Threshold
TG Driver Pull-Up On Resistance
TG Driver Pull-Down On Resistance
Soft-Start Mode
FB = 0.7V, V_SENSE– = 3.3V, V_IN = 6V
TG High
TG Low
1.2
40
50
65
2.5
2.1
BG R_UP
BG Driver Pull-Up On Resistance
BG High
2.5
BG R_DOWN
BG Driver Pull-down On Resistance
BG Low
1.2
TG Transition Time:
(Note 6)
TG t_r
Rise Time
C_LOAD = 3300pF
25
TG t_f
Fall Time
C_LOAD = 3300pF
25
BG Transition Time:
(Note 6)
BG t_r
Rise Time
C_LOAD = 3300pF
25
BG t_f
Fall Time
C_LOAD = 3300pF
25
TG/BG t_1D
Top Gate Off to Bottom Gate On Delay C_LOAD = 3300pF Each Driver
30
Synchronous Switch-On Delay Time
BG/TG t_2D
Bottom Gate Off to Top Gate On Delay C_LOAD = 3300pF Each Driver
30
Top Switch-On Delay Time
t_ON(MIN)
Minimum On-Time
(Note 7)
75
INTV_CC Linear Regulator
V_INTVCC
Internal V_CC Voltage
6V < V_IN < 38V
4.8
5.0
5.2
V_LDO INT
Oscillator
INTV_CC Load Regulation
I_CC = 0 to 20mA
0.2
1.0
f_SW
Switching Frequency
360
400
440
UNITS
V
V
nA
%/V
%
%
mmho
MHz
mA
µA
V
mV
V
µA
%
µA
V
V
mV
Ω
Ω
Ω
Ω
ns
ns
ns
ns
ns
ns
ns
V
%
kHz
3854fb
3