lt1766efe-trpbf Linear Technology Corporation, lt1766efe-trpbf Datasheet - Page 4

• Manufacturer Part Number: lt1766efe-trpbf
• Description: High Voltage 1.5a, 200khz Step-down Switching Regulators
• Manufacturer: Linear Technology Corporation

LT1766/LT1766-5
ELECTRICAL CHARACTERISTICS
The
V
PARAMETER
V
V
Switch Current Limit
Switch On Resistance
Maximum Switch Duty Cycle
Switch Frequency
f
f
Minimum Input Voltage
Minimum Boost Voltage
Boost Current (Note 5)
Input Supply Current (I
Bias Supply Current (I
Shutdown Supply Current
Lockout Threshold
Shutdown Thresholds
Minimum SYNC Amplitude
SYNC Frequency Range
SYNC Input Resistance
Note 1: Absolute Maximum Ratings are those values beyond which the life of a
device may be impaired.
Note 2: Gain is measured with a V
level to 200mV below the upper clamp level.
Note 3: Minimum input voltage is not measured directly, but is guaranteed by
other tests. It is defined as the voltage where internal bias lines are still regulated
so that the reference voltage and oscillator remain constant. Actual minimum
input voltage to maintain a regulated output will depend upon output voltage and
load current. See Applications Information.
Note 4: This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the internal power switch.
Note 5: Boost current is the current flowing into the BOOST pin with the pin held
5V above input voltage. It flows only during switch on time.
Note 6: Input supply current is the quiescent current drawn by the input pin when
the BIAS pin is held at 5V with switching disabled. Bias supply current is the
current drawn by the BIAS pin when the BIAS pin is held at 5V. Total input
referred supply current is calculated by summing input supply current (I
a fraction of bias supply current (I
With V
Note 7: Switch on resistance is calculated by dividing V
4
SW
SW
C
C
IN
Switching Threshold
High Clamp
I
= 15V, V
Line Regulation
Frequency Shifting Threshold
TOTAL
●
IN
denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
= 15V, V
= I
VIN
C
+ (I
= 1.5V, SHDN = 1V, BOOST open circuit, SW open circuit, unless otherwise noted.
OUT
BIAS
= 5V, I
BIAS
)(V
VIN
OUT
VIN
)
)
/V
= 1.4mA, I
IN
BIAS
C
)
swing equal to 200mV above the low clamp
):
BIAS
= 2.9mA, I
IN
TOTAL
to SW voltage by the
CONDITIONS
Duty Cycle = 0
SHDN = 1V
V
I
FB = 1V or V
V
5.5V ≤ V
Df = 10kHz
(Note 3)
(Note 4) I
Boost = V
Boost = V
(Note 6) V
(Note 6) V
SHDN = 0V, V
V
V
V
SW
C
C
C
C
C
Open, Boost = V
Set to Give DC = 50%
Open
Open, Shutting Down
Open, Starting Up
= 2.4mA.
= 0.75A, Boost = V
IN
SW
IN
IN
BIAS
BIAS
≤ 60V
VIN
+ 5V, I
+ 5V, I
(LT1766H GRADE)
SENSE
≤ 0.75A
IN
) with
= 5V
= 5V
≤ 60V, SW = 0V, V
= 4.1V
SW
SW
IN
+ 5V, FB = 1V or V
= 0.5A
= 0.75A
IN
+ 5V (Note 7)
forced current. See Typical Performance Characteristics for the graph of switch
voltage at other currents.
Note 8: The LT1766EGN, LT1766EGN-5, LT1766EFE and LT1766EFE-5 are
guaranteed to meet performance specifications from 0°C to 125°C junction
temperature. Specifications over the –40°C to 125°C operating junction
temperature range are assured by design, characterization and correlation with
statistical process controls. The LT1766IGN, LT1766IGN-5, LT1766IFE and
LT1766IFE-5 are guaranteed over the full
–40°C to 125°C operating junction temperature range. The LT1766HGN and
LT1766HFE are guaranteed over the full –40°C to 140°C operating junction
temperature range.
Note 9: Transconductance and voltage gain refer to the internal amplifier exclusive
of the voltage divider. To calculate gain and transconductance, refer to the SENSE
pin on fixed voltage parts. Divide the values shown by the ratio V
Note 10: This IC includes overtemperature protection that is intended to protect
the device during momentary overload conditions. Junction temperature will
exceed 140°C when overtemperature protection is active. Continuous operation
above the specified maximum operating junction temperature may impair device
reliability.
Note 11: High junction temperatures degrade operating lifetimes. Operating
lifetime at junction temperatures between 125°C and 140°C is derated to 1000
hours.
C
Open
SENSE
= 4.1V
●
●
●
●
●
●
●
●
●
●
●
●
●
●
MIN
0.75
0.15
0.25
184
135
228
2.3
93
90
0.05
2.42
0.37
0.45
TYP
200
200
0.9
2.1
0.2
0.8
4.6
1.8
1.4
2.9
1.5
96
12
45
25
20
2
J
= 25°C.
MAX
0.15
2.68
216
228
100
120
500
700
0.3
0.8
5.5
2.2
4.2
0.9
0.9
2.2
40
3
3
OUT
/1.219.
UNITS
1766fb
%/V
kHz
kHz
kHz
mA
mA
mA
mA
kΩ
µA
µA
%
%
Ω
Ω
V
V
A
V
V
V
V
V
V
V