TC1221/TC1222

DS21367B-page 4

 2002 Microchip Technology Inc.

3.0

DETAILED DESCRIPTION

The TC1221/TC1222 charge pump converters invert

of a two-phase operation (Figure 3-1). During the first

phase, switches S2 and S4 are opened and S1 and S3

are closed. During this time, C1 charges to the voltage

second phase, S2 and S4 are closed, and S1 and S3

are opened. This action connects C1 across C2,

restoring charge to C2.

FIGURE 3-1:

IDEAL SWITCHED

CAPACITOR CHARGE

PUMP

C1

C2

TC1221/1222

Phase 1

S1

S3

S4

S2

OSC