LT1615/LT1615-1
TYPICAL PERFOR A CE CHARACTERISTICS
Switch Saturation Voltage
(V
CESAT
)
0.60
0.55
QUIESCENT CURRENT (µA)
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
1.20
–50
–25
0
25
50
TEMPERATURE (°C)
75
0
100
15
–50
–25
0
25
50
TEMPERATURE (°C)
75
100
FEEDBACK VOLTAGE (V)
SWITCH VOLTAGE (V)
I
SWITCH
= 500mA
I
SWITCH
= 300mA
Switch Off Time
550
500
400
350
SWITCH OFF TIME (ns)
450
400
350
300
250
–50
V
IN
= 1.2V
V
IN
= 12V
PEAK CURRENT (mA)
300
250
200
150
LT1615
V
IN
= 1.2V
SHUTDOWN PIN CURRENT (µA)
–25
0
25
50
TEMPERATURE (°C)
PI FU CTIO S
SW (Pin 1):
Switch Pin. This is the collector of the internal
NPN power switch. Minimize the metal trace area con-
nected to this pin to minimize EMI.
GND (Pin 2):
Ground. Tie this pin directly to the local
ground plane.
FB (Pin 3):
Feedback Pin. Set the output voltage by
selecting values for R1 and R2 (see Figure 1):
SHDN (Pin 4):
Shutdown Pin. Tie this pin to 0.9V or higher
to enable the device. Tie below 0.25V to turn off the device.
V
IN
(Pin 5):
Input Supply Pin. Bypass this pin with a
capacitor as close to the device as possible.
V
OUT
R1
=
R2
−
1
1.23
U W
75
Feedback Pin Voltage and
Bias Current
1.25
50
25
Quiescent Current
V
FB
= 1.23V
NOT SWITCHING
1.24
VOLTAGE
1.23
40
BIAS CURRENT (nA)
23
30
21
V
IN
= 12V
19
V
IN
= 1.2V
17
1.22
CURRENT
20
1.21
10
1615/-1 G01
1615/-1 G02
1615/-1 G03
Switch Current Limit
V
IN
= 12V
25
Shutdown Pin Current
20
15
25°C
10
100°C
5
LT1615-1
100
V
IN
= 12V
V
IN
= 1.2V
50
100
0
–50
0
–25
0
25
50
TEMPERATURE (°C)
75
100
0
5
10
SHUTDOWN PIN VOLTAGE (V)
15
1615/-1 G03
1615/-1 G04
1615/-1 G05
U
U
U
3
LINER [ LINEAR TECHNOLOGY ]
