LTC1473IGN datasheet(11/16 Pages) LINER

11 / 16 page

LTC1473

APPLICATIONS INFORMATION

VGG Regulator Inductor and Capacitors

The VGG regulator provides a power supply voltage 8.5V

higher than any of the three main power source voltages

to allow the control of N-channel MOSFET switches. This

micropower, step-up voltage regulator is powered by the

highest potential available from the three main power

sources for maximum regulator efficiency.

BAT1

BAT2

DCIN

VGG

SWITCHING

REGULATOR

V+

GND

1473 F05

VGG

L1*

1mH

µF

50V

µF

50V

TO GATE

DRIVERS

(8.5V + V+)

LTC1473

*COILCRAFT 1812LS-105 XKBC. (708) 639-6400

Figure 5. VGG Step-Up Switching Regulator

Three external components are required by the VGG regu-

lator: L1, C1 and C2, as shown in Figure 5.

L1 is a small, low current, 1mH surface mount inductor. C1

provides filtering at the top of the 1mH switched inductor

and should be at least 1

µF to filter switching transients.

The VGG output capacitor, C2, provides storage and filter-

ing for the VGG output and should be at least 1µF and rated

for 50V operation. C1 and C2 can be ceramic capacitors.

LTC1473IGN Datasheet(PDF) 11 Page - Linear Technology