LT1507
ELECTRICAL CHARACTERISTICS
T = 25°C, V = 5V, V = 1.5V, boost open, switch open unless otherwise specified.
J
IN
C
PARAMETER
Switch Frequency
CONDITIONS
V Set to Give 50% Duty Cycle
MIN
TYP
500
MAX
UNITS
460
440
440
540
560
570
kHz
kHz
kHz
C
–25°C ≤ T ≤ 125°C
J
T ≤ –25°C
J
Switch Frequency Line Regulation
Frequency Shifting Threshold on F Pin
Minimum Input Voltage (Note 2)
Minimum Boost Voltage (Note 3)
Boost Current (Note 4)
4.3V ≤ V ≤ 15V
∆f = 10kHz
●
●
●
●
0.05
1.0
4
3
12
0.15
1.3
4.3
3.5
22
25
35
40
%/V
V
IN
0.8
B
V
V
mA
mA
mA
mA
I
≤ 1.5A
SW
V
= V + 5V
I
I
= 500mA, –25°C ≤ T ≤ 125°C
BOOST
IN
SW
SW
J
T ≤ –25°C
J
= 1.5A, –25°C ≤ T ≤ 125°C
25
J
T ≤ –25°C
J
Input Supply Current (Note 5)
Shutdown Supply Current
●
3.8
15
5.4
50
75
mA
µA
µA
V
V
= 0V, V ≤ 12V
SHDN
IN
= 0V, V Open
●
●
SW
C
Lockout Threshold
V Open
C
2.3
2.38
2.46
V
Shutdown Threshold
V Open
C
Device Shutting Down
Device Starting Up
●
●
0.15
0.25
0.37
0.45
0.70
0.70
V
V
Minimum Synchronizing Amplitude
●
1.5
2.2
V
Synchronizing Frequency Range (Note 7)
580
1000
kHz
The
range.
●
denotes specifications which apply over the operating temperature
Note 5: Input supply current is the bias current drawn by the V pin when
the SHDN pin is held at 1V (switching disabled).
IN
Note 1: Gain is measured with a V swing equal to 200mV above the low
clamp level to 200mV below the upper clamp level.
Note 6: Switch ON resistance is calculated by dividing V to V voltage
IN SW
by the forced current (1.5A). See Typical Performance Characteristics for
the graph of switch voltage at other currents.
Note 7: For synchronizing frequency above 700kHz, with duty cycles
above 50%, external slope compensation may be needed. See Applications
Information.
Note 8: Transconductance and voltage gain refer to the internal amplifier
exclusive of the voltage divider. To calculate gain and transconductance
refer to SENSE pin on fixed voltage parts. Divide values shown by the ratio
C
Note 2: 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 frequency remain
constant. Actual minimum input voltage to maintain a regulated output will
depend on output voltage and load current. See Applications Information.
Note 3: This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the internal power switch.
V
/2.42.
OUT
Note 4: 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.
W
U
TYPICAL PERFORMANCE CHARACTERISTICS
VC Pin Shutdown Threshold
Switch Peak Current Limit
Feedback Pin Voltage and Current
2.44
2.43
2.42
2.41
2.40
2.0
1.5
1.0
0.5
0
100
90
80
70
60
50
1.4
1.2
1.0
0.8
0.6
0.4
V
IN
V
OUT
= 5V
= 3.3V
VOLTAGE
CURRENT
–25
0
25
50
75
125
–50
100
0
0.25
0.50
0.75
1.00
1.25
–25
0
25
50
75
125
–50
100
JUNCTION TEMPERATURE (°C)
LOAD CURRENT (A)
JUNCTION TEMPERATURE (°C)
LT1507 • TPC03
LT1507 • TA02
LT1507 • TPC01
3
Linear [ Linear ]
