LT3463/LT3463A
U W
TYPICAL PERFOR A CE CHARACTERISTICS
VCESAT and VDIODE Voltage
VREF and VFB1 Voltage
VFB2 Voltage
900
800
700
600
500
400
300
200
100
0
1.27
1.26
1.25
1.24
1.23
1.22
10
FOR BOTH SWITCHERS
8
6
4
2
0
I
= 150mA
DIODE
V
REF
V
FB1
I
= 150mA
SWITCH
–25
0
25
50
75
125
–50
100
–25
0
25
50
75
125
–50
25
50
75
100 125
–50
100
–25
0
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
3463 G01
3463 G02
3463 G03
Quiescent Current
Switch Off Time
Switch Current Limit
400
350
300
250
200
150
100
50
450
400
350
300
250
200
150
100
50
60
50
40
30
20
10
0
LT3463A SW2
LT3463 SW1, SW2
LT3463A SW1
NOT SWITCHING
V
FB1
V
FB2
= 1.3V
= –0.1V
0
–50
0
–25
0
25
50
75
125
–25
0
25
50
75
125
100
–50
100
50
0
TEMPERATURE (°C)
100 125
–50 –25
25
75
TEMPERATURE (°C)
TEMPERATURE (°C)
3463 G04
3463 G05
3463 G06
U
U
U
PI FU CTIO S
VOUT1 (Pin 1): Output Voltage Switcher 1. This is the
cathode of an internal Schottky diode whose anode is
connected to the SW1 pin.
D2 (Pin 5): Diode for Switcher 2. This is the anode of an
internal Schottky diode whose cathode connected to the
GND pin.
SW1 (Pin 2): Switch Pin for Switcher 1. This is the
collector of the internal NPN switch. Minimize the metal
trace area connected to this pin to minimize EMI.
FB2 (Pin 6): Feedback Pin for Switcher 2. Set the output
voltage by selecting values for R3 and R4.
VREF (Pin 7): Voltage Reference Pin (1.25V). This pin is
used along with FB2 to set the negative output voltage for
Switcher 2.
VIN (Pin 3): Input Supply Pin. Bypass this pin with a
capacitor as close to the device as possible.
SW2 (Pin 4): Switch Pin for Switcher 2. This is the
collector of the internal NPN switch. Minimize the metal
trace area connected to this pin to minimize EMI.
SHDN2 (Pin 8): Shutdown Pin for Switcher 2. Pull this pin
above 1.5V to enable Switcher 2. Pull below 0.3V to turn
it off. Do not leave this pin floating.
3463f
3
Linear Systems [ Linear Systems ]
