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| LTC3834 Datasheet, PDF (3/28 Pages) Linear Technology – 30μA IQ Synchronous Step-Down Controller | |||
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LTC3834
ELECTRICAL CHARACTERISTICS The l denotes the speciï¬cations which apply over the full operating
temperature range, otherwise speciï¬cations are at TA = 25°C. VIN = 12V, VRUN = 5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Main Control Loops
VFB
Regulated Feedback Voltage
(Note 4); ITH Voltage = 1.2V
l 0.792 0.800 0.808
IVFB
Feedback Current
(Note 4)
â5 â50
VREFLNREG Reference Voltage Line Regulation VIN = 4V to 30V (Note 4)
0.002 0.02
VLOADREG Output Voltage Load Regulation
(Note 4)
Measured in Servo Loop; ÎITH Voltage = 1.2V to 0.7V l
Measured in Servo Loop; ÎITH Voltage = 1.2V to 2V l
0.1 0.5
â0.1 â0.5
gm
Transconductance Ampliï¬er gm
ITH = 1.2V; Sink/Source 5μA (Note 4)
0.5
IQ
Input DC Supply Current
Sleep Mode
Shutdown
(Note 5)
RUN = 5V, VFB = 0.83V (No Load)
VRUN = 0V
30
50
4
10
UVLO
Undervoltage Lockout
VIN Ramping Down
l
3.7
4
VOVL
Feedback Overvoltage Lockout
Measured at VFB Relative to Regulated VFB
8
10
12
ISENSE
Sense Pins Total Source Current
VSENSEâ = VSENSE+ = 0V
â220
DFMAX
Maximum Duty Factor
In Dropout
98 99.4
ITRACK/SS Soft-Start Charge Current
VTRACK = 0V
0.85 1.1 1.45
VRUN ON
RUN Pin ON Threshold
VRUN Rising
VSENSE(MAX) Maximum Current Sense Threshold VFB = 0.7V, VSENSEâ = 3.3V
0.5 0.7 0.9
l 85 100 115
TG Transition Time:
TG tr
Rise Time
TG tf
Fall Time
(Note 6)
CLOAD = 3300pF
CLOAD = 3300pF
50
90
50
90
BG Transition Time:
BG tr
Rise Time
BG tf
Fall Time
(Note 6)
CLOAD = 3300pF
CLOAD = 3300pF
40
90
40
80
V
nA
%/V
%
%
mmho
μA
μA
V
%
μA
%
μA
V
mV
ns
ns
ns
ns
TG/BG t1D
Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF
Synchronous Switch-On Delay Time
70
ns
BG/TG t2D
Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF
Top Switch-On Delay Time
70
ns
tON(MIN)
Minimum On-Time
INTVCC Linear Regulator
VINTVCCVIN Internal VCC Voltage
VLDOVIN
INTVCC Load Regulation
VINTVCCEXT Internal VCC Voltage
VLDOEXT
INTVCC Load Regulation
VEXTVCC
EXTVCC Switchover Voltage
VLDOHYS
EXTVCC Hysteresis
Oscillator and Phase-Locked Loop
(Note 7)
8.5V < VIN < 30V, VEXTVCC = 0V
ICC = 0mA to 20mA, VEXTVCC = 0V
VEXTVCC = 8.5V
ICC = 0mA to 20mA, VEXTVCC = 8.5V
EXTVCC Ramping Positive
200
ns
5
5.25 5.5
V
0.2 1.0
%
7.2 7.5 7.8
V
0.2 1.0
%
4.5 4.7
V
0.2
V
fNOM
fLOW
fHIGH
fSYNCMIN
fSYNCMAX
IPLLLPF
Nominal Frequency
Lowest Frequency
Highest Frequency
Minimum Synchronizable Frequency
Maximum Synchronizable Frequency
Phase Detector Output Current
Sinking Capability
Sourcing Capability
VPLLLPF = No Connect
VPLLLPF = 0V
VPLLLPF = INTVCC
PLLIN/MODE = External Clock; VPLLLPF = 0V
PLLIN/MODE = External Clock; VPLLLPF = 2V
fPLLIN/MODE < fOSC
fPLLIN/MODE > fOSC
360 400 440
kHz
220 250 280
kHz
475 530 580
kHz
115 140
kHz
650 800
kHz
â5
μA
5
μA
3834fb
3
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