LT1374
ELECTRICAL CHARACTERISTICS
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:
V
IN
supply current is the current drawn when the BIAS pin is held
at 5V and switching is disabled. If the BIAS pin is unavailable or open
circuit, the sum of V
IN
and BIAS supply currents will be drawn by the V
IN
pin.
Note 7:
Switch on resistance is calculated by dividing V
IN
to V
SW
voltage
by the forced current (4.5A). See Typical Performance Characteristics for
the graph of switch voltage at other currents.
Note 8:
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 the fixed voltage parts. Divide values shown by
the ratio V
OUT
/2.42.
Note 9:
Slope compensation is the current subtracted from the switch
current limit at 80% duty cycle. See Maximum Output Load Current in the
Applications Information section for further details.
TYPICAL PERFOR A CE CHARACTERISTICS
Switch Voltage Drop
500
450
400
125°C
6.5
6.0
SWITCH PEAK CURRENT (A)
SWITCH VOLTAGE (mV)
350
300
250
200
150
100
50
0
0
1
4
3
SWITCH CURRENT (A)
2
5
1374 G18
5.5
5.0
MINIMUM
4.5
4.0
3.5
3.0
0
20
60
40
DUTY CYCLE (%)
80
100
1374 G02
25°C
FEEDBACK VOLTAGE (V)
Shutdown Pin Bias Current
500
400
300
200
8
4
0
–50 –25
CURRENT REQUIRED TO FORCE SHUTDOWN
(FLOWS OUT OF PIN). AFTER SHUTDOWN,
CURRENT DROPS TO A FEW
µA
2.40
SHUTDOWN PIN VOLTAGE (V)
2.36
INPUT SUPPLY CURRENT (µA)
CURRENT (µA)
AT 2.38V STANDBY THRESHOLD
(CURRENT FLOWS OUT OF PIN)
50
25
75
0
TEMPERATURE (°C)
4
U W
– 40°C
100
1374 G04
Switch Peak Current Limit
2.430
Feedback Pin Voltage
TYPICAL
2.425
2.420
2.415
2.410
– 50
–25
0
25
50
75
100
125
TEMPERATURE (°C)
1374 G03
Standby and Shutdown Thresholds
25
STANDBY
Shutdown Supply Current
V
SHDN
= 0V
20
2.32
15
0.8
START-UP
0.4
SHUTDOWN
10
5
125
0
–50 –25
0
50
100
25
75
0
JUNCTION TEMPERATURE (°C)
125
0
5
10
15
INPUT VOLTAGE (V)
20
25
1374 G06
1374 G05
1374fb
LINER [ LINEAR TECHNOLOGY ]
