LT3430 Linear Technology, LT3430 Datasheet - Page 3

• Manufacturer Part Number: LT3430
• Description: High Voltage/ 3A/ 200kHz Step-Down Switching Regulator
• Manufacturer: Linear Technology

ELECTRICAL CHARACTERISTICS
The
V
PARAMETER
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
clamp 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
IN
= 15V, V
denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
C
= 1.5V, SHDN = 1V, BOOST = Open Circuit, SW = Open Circuit, unless otherwise noted.
BIAS
VIN
)
)
C
swing equal to 200mV above the low
CONDITIONS
(Note 3)
(Note 4) I
Boost = V
Boost = V
(Note 6) V
(Note 6) V
SHDN = 0V, V
V
– 40 C T
25 C T
V
V
C
C
C
Open
Open, Shutting Down
Open, Starting Up
J
SW
IN
IN
BIAS
BIAS
J
< 25 C
+ 5V, I
+ 5V, I
125 C
IN
= 5V
= 5V
3A
60V, SW = 0V, V
SW
SW
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
With V
Note 7: Switch on resistance is calculated by dividing V
the forced current (3A). See Typical Performance Characteristics for the
graph of switch voltage at other currents.
Note 8: The LT3430EFE is 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
LT3430IFE is guaranteed over the full –40 C to 125 C operating junction
temperature range.
Note 9: See Peak Switch Current Limit vs Junction Temperature graph in
the Typical Performance Characteristics section.
= 1A
= 3A
I
TOTAL
IN
= 15V, V
= I
VIN
C
Open
VIN
+ (I
OUT
) with a fraction of bias supply current (I
BIAS
= 5V, I
)(V
OUT
VIN
/V
= 1.4mA, I
IN
)
0.15
0.25
MIN
228
2.2
2.3
BIAS
= 2.9mA, I
2.38
0.37
0.42
TYP
4.6
1.8
1.5
3.1
1.5
25
75
35
20
J
IN
MAX
= 25 C.
2.48
2.48
0.58
0.60
120
100
200
700
5.5
2.2
4.2
50
TOTAL
to SW voltage by
3
LT3430
BIAS
sn3430 3430is
= 2.4mA.
):
UNITS
3
kHz
mA
mA
mA
mA
k
V
V
A
A
V
V
V
V
V