TC4420/TC4429 internal diagrams.
Fig. 1

TC4420 MOSFET Driver Various Circuits


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Here I will illustrate some basic circuits using the TC4420/TC4429. A TC4429 differs from the TC4420 in that it inverts the input - HIGH in LOW out.

The internal equivalent diagram is shown in Fig. 1. It takes care of interfacing to CMOS input up to 18V or 3.3V or 5V inputs. It requires no additional components.

The to output MOSFETs operate at 6A peak with delay time of only 55ns (typical) output rise and fall times of only 25ns.

For more on this see the following:

Two TC4420 MOSFET drivers used as an H-bridge motor control.
Fig. 2

Fig. 2 illustrates how to use 2 HB4420 MOSFET drivers as a simple H-bridge. I used a 400mA motor with no problem. Because the TC4420 has no internal noise diodes I had to add 4 1N5819s as shown.

TC4420/TC4429 pin connections and packages.
Fig. 3

Fig. 3 illustrates packages. The TO-220 version can carry a lot of current but is expensive. I used the plastic DIP 8s.

Where to buy these parts? The TC4420CAT the high power TO-220 is available from Mouser or Digikey for $2.95 Qty 1.

A direct substitute is the MCP1406 (non-inverting) and MCP1407 (inverting) for $1.74 Qty 1.

I bought 5 of the TC4420CPA DIP8 off of Ebay for $4.36 with shipping from Taiwan.

TC4420 drives half H-bridge.
Fig. 4

Fig. 4 illustrates what I call a half H-bridge connection.

TC4420 drives half H-bridge sink mode.
Fig. 5

Fig 5 illustrates the "SINK" mode. A HIGH input turns on U2.

TC4420 drives half H-bridge source mode.
Fig. 6

Fig 6 illustrates the "SOURCE" mode. A LOW input turns on U3.

TC4420 drives NPN bipolar transistor.
Fig. 7

Fig. 7 the TC4420 is used to supply "SOURCE" (from internal P-channel MOSFET) current to turn on an NPN bipolar transistor.

Ib is limited by Rb and the TC4420.

TC4420 drives PNP bipolar transistor.
Fig. 8

Fig. 8 the TC4420 is used to supply "SINK" (from internal N-channel MOSFET) current to turn on an PNP bipolar transistor.

Ib is limited by Rb and the TC4420.



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