LTC3802
4
3802f
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC3802 is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified.
Note 4: To ensure proper operation, PV
CC
and BV
CC
(V
BOOST
– V
SW
) must
be greater than V
GS(ON)
of the external MOSFETs.
Note 5: Supply current in normal operation is dominated by the current
needed to charge and discharge the external MOSFET gates. This current
will vary with supply voltage and the external MOSFETs used.
Note 6: Supply current in shutdown is dominated by external MOSFET
leakage and may be significantly higher than the quiescent current drawn
by the LTC3802, especially at elevated temperature.
Note 7: Guaranteed by design, not subject to test.
Note 8: Rise and fall times are measured using 10% and 90% levels. Delay
and nonoverlap times are measured using 50% levels.
Note 9: If V
CMPIN
is less than 90% of its nominal value, BG minimum
pulse width is limited to 400ns.
Note 10: The LTC3802 leading edge modulation architecture does not
have a minimum TG pulse width requirement. The TG minimum pulse
width is limited by the rise and fall times.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range. (Note 3) V
CC
= PV
CC
= BOOST = 5V, unless otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Switcher Switching Characteristics
f
OSC
Oscillator Frequency PLLIN Open or V
PLLIN
= 0V 490 550 610 kHz
V
PLLLPF
= 1.2V 550 kHz
V
PLLLPF
= 0V 250 330 400 kHz
V
PLLLPF
= 2.4V 650 750 850 kHz
R
PLLIN
PLLIN Pull-Down Current Source 5 µA
I
PLLLPF
Phase Detector Output Current
Sourcing Capability f
PLLIN
> f
OSC
–15 µA
Sinking Capability f
PLLIN
< f
OSC
15 µA
Phase TG1↓ vs PLLIN↓ PHASEMD Floats 0 Deg
TG1↓ vs PLLIN↓ V
PHASEMD
= 5V 90 Deg
TG2↓ vs PLLIN↓ PHASEMD Floats 180 Deg
TG2↓ vs PLLIN↓ V
PHASEMD
= 5V 270 Deg
V
PHASEMD
Shutdown Threshold ● 1.2 1.7 V
Floating 2.0 V
90° Phase Threshold ● 3.5 4.0 4.5 V
DC
MIN
Minimum TG Duty Cycle V
PLLIN
= 0V ● 0%
DC
MAX
Maximum TG Duty Cycle V
PLLIN
= 0V, V
CMPIN
= 0.6V (Note 9) ● 86 89 92 %
t
ON(MIN)
TG Minimum Pulse Width (Notes 7, 10) 50 ns
BG Minimum Pulse Width V
CMPIN
= 0V (Note 9) 400 ns
t
NOV
Driver Nonoverlap No Load 10 30 80 ns
R
DS(ON)
TG High R
DS(ON)
I
OUT
= 100mA (Note 7) 1.6 2.20 Ω
TG Low R
DS(ON)
1.3 1.80 Ω
BG High R
DS(ON)
1.8 2.50 Ω
BG Low R
DS(ON)
0.7 1.00 Ω
