LTC3853_15 Datasheet, PDF (3/36 Pages) Linear Technology – Triple Output, Multiphase Synchronous Step-Down Controller

LTC3853
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T_A = 25°C (Note 3), V_IN = 15V, V_RUN1,2,3 = 5V, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Main Control Loops
Output Voltage Range
Channels 1, 2
0.8
5.5
V
Channel 3
0.8
13.5
V
V_FB1,2,3
Regulated Feedback Voltage
Feedback Current
I_TH1,2,3 Voltage = 1.2V, –55°C to 150°C (Note 4)
I_TH1,2,3 Voltage = 1.2V, –40°C to 125°C (Note 4)
I_TH1,2,3 Voltage = 1.2V, 0°C to 85°C (Note 4)
(Note 4)
l 0.790 0.800 0.810
V
l 0.792 0.800 0.808
V
0.794 0.800 0.806
V
–10 –50
nA
I_Q
UVLO
Reference Voltage Line Regulation
Output Voltage Load Regulation
Transconductance Amplifier g_m
Input DC Supply Current
Normal Mode
Shutdown
Undervoltage Lockout on INTV_CC
UVLO Hysteresis
V_IN = 6V to 24V (Note 4)
(Note 4)
Measured in Servo Loop;
DI_TH Voltage = 1.2V to 0.7V
Measured in Servo Loop;
DI_TH Voltage = 1.2V to 1.6V
I_TH1,2,3 = 1.2V, Sink/Source 5µA (Note 4)
(Note 5)
V_IN = 15V
V_RUN1,2,3 = 0V
V_INTVCC Ramping Down
0.002 0.02 %/V
l
0.01 0.1
%
l
–0.01 –0.1
%
2.2
mmho
4.1
mA
42
70
µA
3.35
V
0.5
V
I_SENSE
V_RUN1,2,3
Feedback Overvoltage Lockout
Sense Pin Current
Soft-Start Charge Current
RUN Pin ON Threshold
RUN Pin Hysteresis
Measured at V_FB1,2,3 (H-Grade, MP-Grade)
Measured at V_FB1,2,3
V_SENSE = 3.3V
V_TK/SS1,2,3 = 0V
V_RUN1, V_RUN2, V_RUN3 Rising
l 0.84 0.86 0.89
V
l 0.84 0.86 0.88
V
±1
±2
µA
0.9 1.3 1.7
µA
l 1.1 1.2 1.35
V
80
mV
Maximum Current Sense Threshold I_TH1,2,3 = 1.85V, V_SENSE1,2,3 = 3.3V, I_LIM = 0V
l 22
30
38
mV
I_TH1,2,3 = 1.85V, V_SENSE1,2,3 = 3.3V, I_LIM = 0V (H-, MP- l 21
30
39
mV
Grade)
I_TH1,2,3 = 1.85V, V_SENSE1,2,3 = 3.3V, I_LIM = Float
l 42
50
58
mV
I_TH1,2,3 = 1.85V, V_SENSE1,2,3 = 3.3V, I_LIM = Float (H-, MP- l 41
50
59
mV
Grade)
I_TH1,2,3 = 1.85V, V_SENSE1,2,3 = 3.3V, I_LIM = INTV_CC
l 65
75
85
mV
I_TH1,2,3 = 1.85V, V_SENSE1,2,3 = 3.3V, I_LIM = INTV_CC (H-, l 64
75
86
mV
MP-Grade)
Maximum Duty Factor
In Dropout
97
98
%
TG Driver Pull-Up On-Resistance
TG High
2.6
Ω
TG Driver Pull-Down On-Resistance TG Low
1.5
Ω
BG Driver Pull-Up On-Resistance
BG High
2.4
Ω
BG Driver Pull-Down On-Resistance BG Low
1.1
Ω
TG Transition Time:
Rise Time
Fall Time
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
BG Transition Time:
Rise Time
Fall Time
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
Top Gate Off to Bottom Gate On Delay (Note 6)
Synchronous Switch-On Delay Time C_LOAD = 3300pF Each Driver
25
ns
25
ns
25
ns
25
ns
30
ns
For more information www.linear.com/LTC3853
3853fc
3