LTC3839 Datasheet, PDF (3/50 Pages) Linear Technology – Fast, Accurate, 2-Phase, Single-Output Step-Down DC/DC Controller

LTC3839
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C. V_IN = 15V unless otherwise noted (Note 3).
SYMBOL
PARAMETER
I_VOUTSENSE+
I_{VOUTSENSE–}
V_OUTSENSE+ Input Bias Current
V_{OUTSENSE–} Input Bias Current
g_m(EA)
Error Amplifier Transconductance
t_ON(MIN)1,2
Minimum Top Gate On-Time
t_OFF(MIN)1,2 Minimum Top Gate Off-Time
Current Sensing
V_{SENSE(MAX)1,2}
Maximum Valley Current Sense Threshold
(V_SENSE1,2+ – V_{SENSE1,2–})
V_{SENSE(MIN)1,2}
I_SENSE1,2+
Minimum Valley Current Sense Threshold
(V_SENSE1,2+ – V_{SENSE1,2–})
(Forced Continuous Mode)
SENSE1,2⁺ Pins Input Bias Current
I_{SENSE1,2–}
SENSE1,2^– Pins Input Bias Current
(Internal 500k Resistor to SGND)
Start-Up and Shutdown
CONDITIONS
V_OUTSENSE+ – V_{OUTSENSE–} = 0.6V
V_OUTSENSE+ – V_{OUTSENSE–} = 0.6V
ITH = 1.2V (Note 5)
V_IN = 38V, V_OUT = 0.6V, R_T = 20k (Note 6)
(Note 6)
V_RNG
V_RNG
=
=
2V,
0V,
V_FB
V_FB
=
=
0.57V,
0.57V,
VV_{SSEENNSSEE––}
=
=
2.5V
2.5V
V_RNG = INTV_CC, V_FB = 0.57V, V_SENSE– = 2.5V
V_RNG
V_RNG
=
=
2V,
0V,
V_FB
V_FB
=
=
0.63V,
0.63V,
VV_{SSEENNSSEE––}
=
=
2.5V
2.5V
V_RNG = INTV_CC, V_FB = 0.63V, V_SENSE– = 2.5V
V_SENSE+ = 0.6V
V_SENSE+ = 5V
VV^{SSEENNSSEE––}
=
=
0.6V
5V
MIN TYP MAX UNITS
±5
±25
nA
–25 –50
μA
1.7
mS
30
ns
90
ns
l 80
100
120
mV
l 21
30
40
mV
l 39
50
61
mV
–50
mV
–15
mV
–25
mV
±5
±50
nA
1
±2
μA
1.2
μA
10
μA
V_RUN
I_RUN
UVLO
RUN Pin On Threshold
RUN Pin On Hysteresis
RUN Pin Pull-Up Current when Off
RUN Pin Pull-Up Current Hysteresis
INTV_CC Undervoltage Lockout
I_TRACK/SS
Soft-Start Pull-Up Current
Frequency and Clock Synchronization
V_RUN Rising
V_RUN Falling from On Threshold
RUN = SGND
(I_RUN(ON) – I_RUN(OFF))
INTV_CC Falling
INTV_CC Rising
0V < TRACK/SS < 0.6V
l 1.1
1.2
1.3
V
100
mV
2.5
μA
10
μA
l 3.3
3.7
V
l
4.2
4.5
V
1
μA
f
V_PLLIN(H)
V_PLLIN(L)
R_MODE/PLLIN
Gate Drivers
Clock Output Frequency
(Steady-State Switching Frequency)
Channel 2 Phase (Relative to Channel 1)
CLKOUT Phase (Relative to Channel 1)
Clock Input High Level Into MODE/PLLIN
Clock Input Low Level Into MODE/PLLIN
MODE/PLLIN Input Resistance
R_T = 205k
R_T = 80.6k
R_T = 18.2k
PHASMD = SGND
PHASMD = Floating
PHASMD = INTV_CC
PHASMD = SGND
PHASMD = Floating
PHASMD = INTV_CC
With Respect to SGND
200
kHz
450 500 550
kHz
2000
kHz
180
Deg
180
Deg
240
Deg
60
Deg
90
Deg
120
Deg
2
V
0.5
V
600
kΩ
R_TG(UP)1,2
R_TG(DOWN)1,2
R_BG(UP)1,2
R_BG(DOWN)1,2
t_D(TG/BG)1,2
t_D(BG/TG)1,2
TG Driver Pull-Up On Resistance
TG High
TG Driver Pull-Down On Resistance
TG Low
BG Driver Pull-Up On Resistance
BG High
BG Driver Pull-Down On Resistance
BG Low
Top Gate Off to Bottom Gate On Delay Time (Note 6)
Bottom Gate Off to Top Gate On Delay Time (Note 6)
2.5
Ω
1.2
Ω
2.5
Ω
0.8
Ω
20
ns
15
ns
3839fa
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