LTC3858-1 Datasheet, PDF (3/38 Pages) Linear Technology – Low IQ, Dual 2-Phase Synchronous Step-Down Controller

LTC3858-1
Electrical Characteristics The l denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T_A = 25°C. V_IN = 12V, V_RUN1,2 = 5V, EXTV_CC = 0V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
V_IN
V_FB1,2
Input Supply Operating Voltage Range
Regulated Feedback Voltage
(Note 4) I_TH1,2 = 1.2V
–40°C to 125°C
–40°C to 85°C
4
38
V
l 0.788 0.800 0.812
V
0.792 0.800 0.808
V
I_FB1,2
Feedback Current
(Note 4)
V_REFLNREG Reference Voltage Line Regulation
(Note 4) V_IN = 4.5V to 38V
V_LOADREG Output Voltage Load Regulation
(Note4)
Measured in Servo Loop,
l
∆I_TH Voltage = 1.2V to 0.7V
(Note4)
Measured in Servo Loop,
l
∆I_TH 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
(Both Channels On)
RUN1,2 = 5V, V_FB1,2 = 0.83V (No Load)
±5
±50
nA
0.002 0.02
%/V
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
170
250
µA
300
450
µA
8
20
µA
UVLO
V_OVL
I_SENSE+
I_SENSE–
Undervoltage Lockout
Feedback Overvoltage Protection
SENSE⁺ Pin Current
SENSE^– Pins Current
DF_MAX
I_SS1,2
V_RUN1,2 On
V_RUN1,2 Hyst
V_SS1,2 LA
Maximum Duty Factor
Soft-Start Charge Current
RUN Pin On Threshold Voltage
RUN Pin Hysteresis Voltage
SS Pin Latch-Off Arming Threshold
Voltage
INTV_CC Ramping Up
INTV_CC Ramping Down
l
4.0
4.2
V
l 3.6
3.8
4.0
V
Measured at V_FB1,2, Relative to Regulated V_FB1,2
7
10
13
%
Each Channel
±1
µA
Each Channel
V_OUT1,2 < INTV_CC – 0.5
V_OUT1,2 > INTVCC + 0.5
In Dropout, FREQ = 0V
±1
µA
540
700
µA
98
99.4
%
V_SS1,2 = 0V
V_RUN1, V_RUN2 Rising
0.7
1.0
1.4
µA
l 1.23 1.28 1.33
V
50
mV
V_SS1, V_SS2 Rising from 1V
1.9
2
2.1
V
V_SS1,2 LT
I_DSC1,2 LT
SS Pin Latch-Off Threshold Voltage
SS Discharge Current
V_SENSE(MAX) Maximum Current Sense Threshold
Voltage
V_SS1, V_SS2 Rising from 2V
Short-Circuit Condition V_FB1,2 = 0.5V
V_SS1,2 = 4.5V
V_FB1,2 = 0.7V, V_SENSE1–,₂– = 3.3V
1.3
1.5
1.7
V
7
10
13
µA
l 43
50
57
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
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