BUK221-50DY Datasheet, PDF (4/16 Pages) NXP Semiconductors – Dual channel high-side TOPFET

Philips Semiconductors
BUK221-50DY
Dual channel high-side TOPFET™
4. Functional description
A diagnostic status ensures faster fault detection.
Active current limit is combined with latched short circuit protection in order to
protect the device in the event of a short circuit.
Thermal shutdown for high temperature conditions has an automatic restart at a
lower temperature so providing protection against excessive power dissipation.
Active clamping protects the device against low energy spikes.
Undervoltage lockout means the device shuts down for low battery voltages, thus
avoiding faulty operation.
Overvoltage shutdown in the on-state protects a load such as a lamp filament from
potentially destructive voltage spikes.
Table 3: Truth table
Abbreviations: L = logic LOW; H = logic HIGH; X = don’t care; 0 = condition not present; 1 = condition present;
UV = undervoltage; OV = overvoltage; OC = open circuit load; SC = short circuit; OT = overtemperature ^[1].
Input
Supply
Load 1
Load 2
Load output Status Operating mode
1 2 UV OV OC SC OT OC SC OT 1
2
L L 0 X 0 X X 0 X X OFF OFF H both off & normal
L L 0 X 1 X X X X X OFF OFF
L both off, one/both OC or
shorted to V_S or battery;
Figure 10
L H 0 X 1 X X 0 0 0 OFF ON
L one off & OC, with other on
& normal
H L 0 0 0 0 0 0 0 0 ON OFF H one on & normal, with other
off & normal
H H 0 0 0 0 0 0 0 0 ON ON
H both on & normal
H X 1 0 X X X 0 X X OFF OFF H supply undervoltage lockout
H X 0 1 X 0 0 X 0 0 OFF OFF H supply overvoltage
shutdown
H X 0 0 0 1 X X X X OFF X
L one SC tripped
H L 0 0 0 1 X 0 0 X OFF OFF
L one SC tripped, with other
off & normal
H H 0 0 0 1 X 0 0 0 OFF ON
L one SC tripped, with other
on & normal
H X 0 0 0 0 1 X X X OFF X
L one OT shutdown
H L 0 0 0 0 1 0 0 X OFF OFF
L one OT shutdown, with other
off & normal
H H 0 0 0 0 1 0 0 0 OFF ON
L one OT shutdown, with other
on & normal
[1] The status will continue to indicate OT (even if the input goes LOW) until the device cools below the reset threshold temperature.
See “Overtemperature protection” characteristics in Table 6 “Static characteristics”.
9397 750 11167
Product data
Rev. 01 — 16 April 2003
© Koninklijke Philips Electronics N.V. 2003. All rights reserved.
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