AN2208 datasheet(7/51 Pages) STMICROELECTRONICS

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AN2208

1 High-side driver description

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High-side driver description

The VN808 (Figure 2) is a high-side driver (HSD) used to drive eight independent loads. Active

current limitation combined with thermal shutdown and automatic restart functions protect the

device against overload. A thermal case substrate protection is implemented to protect the FRx

substrate under short circuit and worst case ambient conditions in terms of reliability. The

device automatically turns off when the ground pin is disconnected. The VN340SP and VN808

are especially suitable for use with programmable logic controllers (PLC) in industrial

applications.

The VN340SP (Figure 3) is used to drive four independent resistive, capacitive and inductive

loads in high-side configurations. Active current limitation prevents the system power supply

from dropping in the event of a short load. A built-in thermal shutdown circuit protects the chip

from high temperatures and short circuits. Each I/O is pulled down when an over-temperature

condition of the relative channel is detected and restarts after reaching the lower thermal

threshold. The system oscillates depending on the thermal impedance of the application.

Table 1.

VN808 and VN340SP main characteristics

VN340SP HSD

VN808 HSD

Output current per channel 0.5A at 24V

Built-in current limiter

Short-load and overtemperature (Junction)

protection

Short-load and overtemperature (Junction and

Case) protection

Under-voltage shutdown

Open-drain diagnostic output

Status output current 2 to 4 mA

DC supply voltage 36V

DC supply voltage 45V

Very low stand-by current

AN2208 Datasheet(PDF) 7 Page - STMicroelectronics