FS220

Technology

2 Phase High Voltage DC Motor Driver IC

Rev0.5 May 11, 2005(LF)

Darlington-Pair Transistor Output

The figure 4 is the circuit diagram of Darlington-pair transistor. Under the heavy current

loading, the power loss of the high saturation voltage can be calculated into the following

formula:

According to the IC package and the curve of the power loss, the Pc should be applied to

and within the safety value.

60V is the voltage of Zener breakdown diode. However, if the voltage, excluding that of the

power supply, is more than 60V under the long-time operation, the diode will be destroyed.

2,3

Q2

+

_

+

_

V

B E

V

CE(SAT)

Q1

Fig.4 Darlington-pair Transistor Circuits