LT3434IFE#PBF Linear Technology, LT3434IFE#PBF Datasheet - Page 6

• Manufacturer Part Number: LT3434IFE#PBF
• Description: IC REG SW BUCK 3A 200KHZ 16TSSOP
• Manufacturer: Linear Technology
• Type: Step-Down (Buck)r

Specifications of LT3434IFE#PBF

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.25 ~ 54 V
• Current - Output: 3A
• Frequency - Switching: 200kHz
• Voltage - Input: 3.3 ~ 60 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP Exposed Pad, 16-eTSSOP, 16-HTSSOP
• Primary Input Voltage: 60V
• No. Of Outputs: 1
• Output Voltage: 54V
• Output Current: 6.5A
• No. Of Pins: 16
• Operating Temperature Range: -40°C To +125°C
• Msl: MSL 1 - Unlimited
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

LT3434
TYPICAL PERFOR A CE CHARACTERISTICS
500mA/DIV
PI FU CTIO S
NC (Pin 1): No Connection.
SW (Pins 2, 5): The SW pin is the emitter of the on-chip
power NPN switch. This pin is driven up to the input pin
voltage during switch on time. Inductor current drives the
SW pin negative during switch off time. Negative voltage
is clamped with the external catch diode. Maximum nega-
tive switch voltage allowed is –0.8V.
V
NPN switch. V
a voltage on the BIAS pin is not present. High dI/dt edges
occur on this pin during switch turn on and off. Keep the
path short from the V
capacitor, through the catch diode back to SW. All trace
6
50mV/DIV
IN
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
U
0
V
(Pins 3, 4): This is the collector of the on-chip power
I
OUT
OUT
0
3.3V Dropout Operation
V
BOOST DIODE = DIODES INC B1100
OUT
0.5
Burst Mode Operation
V
V
I
Q
IN
OUT
LOAD CURRENT
= 100µA
= 3.3V
= 12V
U
1
= 3.3V
1.5
IN
INPUT VOLTAGE (V)
0.25A
powers the internal control circuitry when
2
2.5
5µs/DIV
U
3
LOAD CURRENT
2.5A
IN
3.5
pin through the input bypass
W
4
4.5
3434 G24
U
3434 G15
5
50mV/DIV
1A/DIV
6
5
2
0
4
3
1
V
I
0
OUT
OUT
5V Dropout Operation
V
BOOST DIODE = DIODES INC B1100
OUT
No Load 2A Step Response
V
V
C
IN
OUT
OUT
1
= 5V
= 12V
LOAD CURRENT
= 3.3V
= 100µF
INPUT VOLTAGE (V)
2
0.25A
3
500µs/DIV
inductance on this path will create a voltage spike at switch
off, adding to the V
BOOST (Pin 6): The BOOST pin is used to provide a drive
voltage, higher than the input voltage, to the internal
bipolar NPN power switch. Without this added voltage, the
typical switch voltage loss would be about 1.5V. The
additional BOOST voltage allows the switch to saturate
and its voltage loss approximates that of a 0.1Ω FET
structure.
C
of delay time between the PGFB pin exceeding its thresh-
old (V
When the PGFB pin rises above V
T
4
(Pin 7): A capacitor on the C
LOAD CURRENT
2.5A
PGFB
5
3434 G25
) and the PG pin set to a high impedance state.
6
3434 G17
500mA/DIV
CE
50mV/DIV
50mV/DIV
1A/DIV
voltage across the internal NPN.
V
V
I
I
OUT
OUT
OUT
OUT
Step Response
V
V
C
I
Burst Mode Operation
V
V
I
LOAD(DC)
Q
IN
OUT
OUT
IN
OUT
= 100µA
= 12V
= 12V
T
= 3.3V
= 100µF
= 3.3V
pin determines the amount
= 500mA
PGFB
, current is sourced
500µs/DIV
5ms/DIV
3434fb
3434 G18
3434 G14