Datasheet LT3463, LT3463A (Analog Devices) - 3

LT3463/LT3463A
W U TYPICAL PERFOR A CE CHARACTERISTICS VCESAT and VDIODE Voltage VREF and VFB1 Voltage VFB2 Voltage
900 1.27 10 FOR BOTH SWITCHERS 800 700 I 1.26 8 DIODE = 150mA 600 VOLTAGE (V) 1.25 VREF 6 500 VOLTAGE (V) DIODE V 400 FB1 FB1 1.24 VOLTAGE (mV) 4 300 AND V AND V FB2V 200 REFV CESAT 1.23 2 V 100 ISWITCH = 150mA 0 1.22 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 3463 G01 3463 G02 3463 G03
Switch Off Time Switch Current Limit Quiescent Current
400 450 60 350 400 LT3463A SW2 50 350 300 µA) 300 40 250 250 200 LT3463 SW1, SW2 30 200 LT3463A SW1 150 150 20 SWITCH OFF TIME (ns) 100 100 QUIESCENT CURRENT ( SWITCH CURRENT LIMIT (mA) 10 NOT SWITCHING 50 50 VFB1 = 1.3V VFB2 = –0.1V 0 0 0 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) 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
D2 (Pin 5):
Diode for Switcher 2. This is the anode of an cathode of an internal Schottky diode whose anode is internal Schottky diode whose cathode connected to the connected to the SW1 pin. GND pin.
SW1 (Pin 2):
Switch Pin for Switcher 1. This is the
FB2 (Pin 6):
Feedback Pin for Switcher 2. Set the output collector of the internal NPN switch. Minimize the metal voltage by selecting values for R3 and R4. trace area connected to this pin to minimize EMI.
VREF (Pin 7):
Voltage Reference Pin (1.25V). This pin is
VIN (Pin 3):
Input Supply Pin. Bypass this pin with a used along with FB2 to set the negative output voltage for capacitor as close to the device as possible. Switcher 2.
SW2 (Pin 4):
Switch Pin for Switcher 2. This is the
SHDN2 (Pin 8):
Shutdown Pin for Switcher 2. Pull this pin collector of the internal NPN switch. Minimize the metal above 1.5V to enable Switcher 2. Pull below 0.3V to turn trace area connected to this pin to minimize EMI. it off. Do not leave this pin floating. 3463f 3