LTC3851A-1_15 Datasheet, PDF (3/30 Pages) Linear Technology – Synchronous Step-Down Switching Regulator Controller

LTC3851A-1
Electrical Characteristics The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C (Note 2). V_IN = 15V, V_RUN = 5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Main Control Loops
V_IN
Input Operating Voltage Range
V_FB
Regulated Feedback Voltage
I_TH = 1.2V (Note 4) 0°C to 85°C
I_TH = 1.2V (Note 4) –40°C to 125°C
I_TH = 1.2V (Note 4) –40°C to 150°C
I_TH = 1.2V (Note 4) –55°C to 150°C
4
38
V
l 0.792 0.800 0.808
V
l 0.788
0.812
V
l 0.788
0.812
V
l 0.788
0.812
V
I_FB
Feedback Current
(Note 4)
V_REFLNREG Reference Voltage Line Regulation
V_IN = 6V to 38V (Note 4)
V_LOADREG Output Voltage Load Regulation
(Note 4) Measured in Servo Loop,
∆I_TH = 1.2V to 0.7V
l
(Note 4) Measured in Servo Loop,
∆I_TH = 1.2V to 0.7V (H-Grade, MP-Grade)
l
–10
–50
nA
0.002 0.02
%/V
0.01
0.1
%
0.2
%
(Note 4) Measured in Servo Loop,
∆I_TH = 1.2V to 1.6V
l
(Note 4) Measured in Servo Loop,
∆I_TH = 1.2V to 1.6V (H-Grade, MP-Grade)
l
g_m
Transconductance Amplifier g_m
I_TH = 1.2V, Sink/Source = 5µA (Note 4)
g_m GBW
Transconductance Amp Gain Bandwidth I_TH = 1.2V (Note 8)
–0.01 –0.1
–0.2
2
3
%
%
mmho
MHz
I_Q
UVLO
UVLO Hys
Input DC Supply Current
Normal Mode
Shutdown
Undervoltage Lockout on INTV_CC
UVLO Hysteresis
(Note 5)
V_RUN = 5V
V_RUN = 0V
V_INTVCC Ramping Down
1
mA
25
50
µA
3.25
V
0.4
V
I_SENSE
SENSE Pins Current
±1
±2
µA
I_TK/SS
Soft-Start Charge Current
V_TK/SS = 0V
0.6
1
2
µA
V_RUN
RUN Pin On—Threshold
V_RUN Rising
l 1.10 1.22 1.35
V
V_RUNHYS
RUN Pin On—Hysteresis
120
mV
V_SENSE(MAX) Maximum Current Sense Threshold
V_FB = 0.7V, V_SENSE = 3.3V
l 40
53
65
mV
V_FB = 0.7V, V_SENSE = 3.3V (H-Grade, MP-Grade) l 35
70
mV
TG R_UP
TG Driver Pull-Up On-Resistance
TG High
2.2
Ω
TG R_DOWN TG Driver Pull-Down On-Resistance
TG Low
1.2
Ω
BG R_UP
BG Driver Pull-Up On-Resistance
BG High
2.1
Ω
BG R_DOWN
TG t_r
TG t_f
BG Driver Pull-Down On-Resistance
TG Transition Time
Rise Time
Fall Time
BG Low
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
1.1
Ω
25
ns
25
ns
BG tr
BG tf
TG/BG t_1D
BG Transition Time
Rise Time
Fall Time
Top Gate Off to Bottom Gate On Delay
Bottom Switch-On Delay Time
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
C_LOAD = 3300pF Each Driver
(Note 6)
25
ns
25
ns
30
ns
BG/TG t_2D
Bottom Gate Off to Top Gate On Delay C_LOAD = 3300pF Each Driver
Top Switch-On Delay Time
(Note 6)
30
ns
t_ON(MIN)
Minimum On-Time
(Note 7)
90
ns
INTV_CC Linear Regulator
V_INTVCC
Internal V_CC Voltage
6V < V_IN < 38V
4.8
5
5.2
V
V_LDO INT
INTV_CC Load Regulation
I_CC = 0mA to 50mA
0.5
%
3851a1fa
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