5

LT1371

TEMPERATURE (

°C)

–50

400

500

600

150

LT1371 • G11

300

200

0

0

50

100

100

800

700

–25

25

75

125

Feedback Input Current

vs Temperature

TEMPERATURE (

°C)

–50

–50

–30

0

0

50

75

LT1371 • G12

–40

–10

–20

–25

25

100 125

150

Negative Feedback Input Current

vs Temperature

Clamp Voltage vs Temperature

TEMPERATURE (

°C)

–50

0.4

0.6

1.0

1.2

1.4

2.4

1.8

0

50

75

LT1371 • G10

0.8

2.0

2.2

1.6

–25

25

100 125

150

sation, current limiting and soft start. It is the output of the

error amplifier and the input of the current comparator.

Loop frequency compensation can be performed with an

FB: The Feedback pin is used for positive output voltage

sensing and oscillator frequency shifting. It is the invert-

ing input to the error amplifier. The noninverting input of

this amplifier is internally tied to a 1.245V reference. Load

on the FB pin should not exceed 250

µA when NFB pin is

used. See Applications Information.

NFB: The Negative Feedback pin is used for negative

output voltage sensing. It is connected to the inverting

input of the negative feedback amplifier through a 100k

source resistor.

S/S (R and T7 Packages Only): Shutdown and Synchroni-

zation Pin. The S/S pin is logic level compatible. Shutdown

is active low and the shutdown threshold is typically 1.3V.

leave it floating. To synchronize switching, drive the S/S

pin between 600kHz and 800kHz.

SHDN: (SW Package Only): The Shutdown pin is active

low and the shutdown threshold is typically 1.3V. For

leave it floating.

SYNC (SW Package Only): To synchronize switching,

drive the SYNC pin between 600kHz and 800kHz. If not

used, the SYNC pin can be tied high, low or left floating.

10

µF or more. The regulator goes into undervoltage lock-

and has large currents flowing through it. Keep the traces

to the switching components as short as possible to

minimize radiation and voltage spikes.

GND: Tie all Ground pins to a good quality ground plane.