TD230

TD230

TD230

TD230

BOARD1

BOARD2

BOARD3

BOARDN

Vcc+

P owe r S upply

GND

Vcc-

Figure 8 :

Decentralized Protection

Therefore, when a fault appears on the positive rail,

the definitive shutdown of the positive NMOS will

lead to the shutdown of the negative NMOS, but

when a fault appears on the negative rail, the

definitive shutdown of the negativeNMOS will have

no effect on the positive NMOS.

Several possibilities are offered to reset the whole

system when it has been led to definitive

shutdown :

• the card can be unplugged and plugged back

(live insertion)

• the INHIBIT pin can be set to active state dur-

ing a short time (100

µs typ or more) in the

case of remote control facilities

3. PERFORMANCES AND EVALUATION

All the curves shown in this application note have

been realized with the TD230 Evaluation Board.

The external conditions and components were as

listed hereafter :

• Vcc+ = 5V

• Vcc- = -5V

• Suppliable output short circuit current = 5A

• IC = TD230

• Positive Bypass = 4.7µF (plastic)

• Negative Bypass = 4.7µF (plastic)

The evaluation board is available and allows to test

the performances of the TD230. The layout and

schematic of this evaluation board are given on

figures 9A-9B-9C.

4. CAUTIONS

For proper use of the TD230 as a reliable protection

device, a few precautions must be taken :

1. Proper bypass capacitors must be connected as

close as possible to the power pins of the TD230

(PVcc, NVcc, GND). Some recommended values

are given in table (a).

2. The OSCGND pin must be tied to the GND pin

externally (printed board) to ensure proper step-up

converter reference. If not, the step-up converter

will not start.

3. The INHIBIT pin is a CMOS/TTL compatible input

which should therefore not be left unconnected.

The absolute maximum rating of this input is 7V. It

should be tied to the TTL compatible output of an

TD230

10/15