TC2682/TC2683/TC2684

DS21548C-page 4

© 2005 Microchip Technology Inc.

3.0

DETAILED DESCRIPTION

The TC2682/TC2683/TC2684 inverting charge pumps

perform a -2x multiplication of the voltage applied to the

synchronous switching matrices and three external

capacitors.

Figure 3-1 is a block diagram representation of the

TC2682/TC2683/TC2684 architecture. The first switch-

first stage to produce the ‘-2X’ output function from the

second stage switching matrix.

Each device contains an on-board oscillator that

synchronously controls the operation of the charge

pump switching matrices. The TC2682 synchronously

switches

at

12kHz,

the

TC2683

synchronously

switches at 35kHz, and the TC2684 synchronously

switches at 125kHz. The different oscillator frequencies

for this device family allow the user to trade-off

capacitor size versus supply current. Faster oscillators

can use smaller external capacitors, but will consume

more

supply

current

(see

Section 1.0

Electrical

Characteristics).

FIGURE 3-1:

TC2682/TC2683/TC2684 ARCHITECTURE

+

Switch Matrix

(1st Stage)

Switch Matrix

(2nd Stage)

Oscillator

C1

+

C2

+