LTC3890 Datasheet, PDF (3/36 Pages) Linear Technology – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller

LTC3890
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T_J = 25°C. V_IN = 12V, V_RUN1,2 = 5V, EXTV_CC = 0V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
V_LOADREG Output Voltage Load Regulation
(Note4)
Measured in Servo Loop,
l
Δ_ITH Voltage = 1.2V to 0.7V
(Note4)
Measured in Servo Loop,
l
Δ_ITH Voltage = 1.2V to 2V
g_m1,2
Transconductance Amplifier g_m
(Note 4) I_TH1,2 = 1.2V, Sink/Source = 5μA
I_Q
Input DC Supply Current
(Note 5)
Pulse Skip or Forced Continuous Mode RUN1 = 5V and RUN2 = 0V or
(One Channel On)
RUN1 = 0V and RUN2 = 5V,
V_FB1 = 0.83V (No Load)
Pulse Skip or Forced Continuous Mode RUN1,2 = 5V, V_FB1,2 = 0.83V (No Load)
(Both Channels On)
0.01
0.1
%
–0.01
2
–0.1
%
mmho
1.3
mA
2
mA
Sleep Mode (One Channel On)
Sleep Mode (Both Channels On)
Shutdown
RUN1 = 5V and RUN2 = 0V or
RUN1 = 0V and RUN2 = 5V,
V_FB1 = 0.83V (No Load)
RUN1,2 = 5V, V_FB1,2 = 0.83V (No Load)
RUN1,2 = 0V
50
75
μA
60
100
μA
14
25
μA
UVLO
Undervoltage Lockout
INTV_CC Ramping Up
INTV_CC Ramping Down
l
4.0
4.2
V
l 3.6
3.8
4.0
V
V_OVL
I_SENSE+
I_SENSE–
Feedback Overvoltage Protection
SENSE⁺ Pin Current
SENSE^– Pins Current
Measured at V_FB1,2, Relative to Regulated V_FB1,2
Each Channel
Each Channel
V_SENSE– < INTV_CC – 0.5V
V_SENSE– > INTV_CC + 0.5V
7
10
13
%
±1
μA
±1
μA
700
μA
DF_MAX
Maximum Duty Factor
In Dropout
98
99
%
I_TRACK/SS1,2 Soft-Start Charge Current
V_TRACK1,2 = 0V
0.7
1.0
1.4
μA
V_RUN1 On
V_RUN2 On
RUN1 Pin On Threshold
RUN2 Pin On Threshold
V_RUN1 Rising
V_RUN2 Rising
l 1.15 1.21
1.27
V
l 1.20 1.25
1.30
V
V_RUN1,2 Hyst RUN Pin Hysteresis
50
mV
V_SENSE(MAX) Maximum Current Sense Threshold
V_FB1,2 = 0.7V, V_SENSE1–,₂– = 3.3V, I_LIM = 0
l 22
30
36
mV
V_FB1,2 = 0.7V, V_SENSE1–,₂– = 3.3V, I_LIM = INTV_CC l 43
50
57
mV
V_FB1,2 = 0.7V, V_SENSE1–,₂– = 3.3V, I_LIM = FLOAT l 64
75
85
mV
Gate Driver
TG1,2
Pull-Up On-Resistance
Pull-Down On-Resistance
2.5
Ω
1.5
Ω
BG1,2
Pull-Up On-Resistance
Pull-Down On-Resistance
2.4
Ω
1.1
Ω
TG1,2 t_r
TG1,2 t_f
BG1,2 t_r
BG1,2 t_f
TG/BG t_1D
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
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
C_LOAD = 3300pF Each Driver
25
ns
16
ns
28
ns
13
ns
30
ns
BG/TG t_1D Bottom Gate Off to Top Gate On Delay C_LOAD = 3300pF Each Driver
Top Switch-On Delay Time
30
ns
t_ON(MIN)
Minimum On-Time
(Note 7)
95
ns
3890f
3