 English |
|
|
|
|
|
|
|
| LTC3704_15 Datasheet, PDF (3/28 Pages) Linear Technology – Wide Input Range, No RSENSE Positive-to-Negative DC/DC Controller | |||
| |||
| ◁ |
LTC3704
ELECTRICAL CHARACTERISTICS
The â denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VIN = VINTVCC = 5V, VRUN = 1.5V, RFREQ = 80k, VMODE/SYNC = 0V, unless otherwise specified.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX
Oscillator
fOSC
Oscillator Frequency
RFREQ = 80k
250
300
350
Oscillator Frequency Range
50
1000
DMAX
Maximum Duty Cycle
87
92
97
fSYNC/fOSC Recommended Maximum Synchronized
Frequency Ratio
fOSC = 300kHz (Note 6)
1.25 1.30
tSYNC(MIN) MODE/SYNC Minimum Input Pulse Width
VSYNC = 0V to 5V
25
tSYNC(MAX)
VIL(MODE)
VIH(MODE)
MODE/SYNC Maximum Input Pulse Width
Low Level MODE/SYNC Input Voltage
High Level MODE/SYNC Input Voltage
VSYNC = 0V to 5V
0.8/fOSC
0.3
1.2
RMODE/SYNC MODE/SYNC Input Pull-Down Resistance
50
VFREQ
Nominal FREQ Pin Voltage
0.62
Low Dropout Regulator
VINTVCC
ÎVINTVCC
ÎVIN1
ÎVINTVCC
ÎVIN2
VLDO(LOAD)
INTVCC Regulator Output Voltage
INTVCC Regulator Line Regulation
INTVCC Regulator Line Regulation
INTVCC Load Regulation
VIN = 7.5V
7.5V ⤠VIN ⤠15V
15V ⤠VIN ⤠30V
VIN = 7.5V, 0 ⤠IINTVCC ⤠20mA
5.0
5.2
5.4
8
25
70
200
â 2 â 0.2
VDROPOUT INTVCC Regulator Dropout Voltage
VINTVCC = Open, INTVCC Load = 20mA
280
IINTVCC
Bootstrap Mode INTVCC Supply
Current in Shutdown
RUN = 0V, SENSE = 5V
10
20
GATE Driver
tr
GATE Driver Output Rise Time
tf
GATE Driver Output Fall Time
CL = 3300pF (Note 7)
CL = 3300pF (Note 7)
17
100
8
100
UNITS
kHz
kHz
%
ns
ns
V
V
kΩ
V
V
mV
mV
%
mV
μA
ns
ns
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliabilty and lifetime.
Note 2: The LTC3704E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the â 40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3704I is guaranteed over the full
â40°C to 125°C operating temperature range.
Note 3: TJ is calculated from the ambient temperature TA and power
dissipation PD according to the following formula:
TJ = TA + (PD ⢠120°C/W)
Note 4: The dynamic input supply current is higher due to power MOSFET
gate charging (QG ⢠fOSC). See Applications Information.
Note 5: The LTC3704 is tested in a feedback loop that servos VNFB to the
reference voltage with the ITH pin forced to a voltage between 0V and 1.4V
(the no load to full load operating voltage range for the ITH pin is 0.3V to
1.23V).
Note 6: In a synchronized application, the internal slope compensation
gain is increased by 25%. Synchronizing to a significantly higher ratio will
reduce the effective amount of slope compensation, which could result in
subharmonic oscillation for duty cycles greater than 50%.
Note 7: Rise and fall times are measured at 10% and 90% levels.
3704fb
3
|
▷ |
German
Russian
Spanish
Italian
Polish
Chinese
Japanese
Korean
French
Portuguese