BU6909AGFT Datasheet, PDF (15/21 Pages) Rohm – Built in HALL element

BU6909AGFT
Datasheet
3) Problem of GND-line PWM switching
Do not perform PWM switching of GND line because GND terminal potential cannot be kept to a minimum.
VCC
M
Motor
Driver
Controller
GND
PWM input
Prohibite
Figure 30. GND Line PWM switching prohibited
4) FG output
FG output is an open drain output and requires pull-up resistor. A VCC voltage that is beyond its absolute maximum
rating when FG output terminal is directly connected to power supply, could damage the IC. The IC can be protected by
adding resistor R1 (as shown in Figure 31).
VCC
Pull-up resistor
FG
R1
Protection resistor
Connector of board
Figure 31. Protection of FG terminal
Thermal derating curve
Thermal derating curve indicates power that can be consumed by IC with reference to ambient temperature. Power that can
be consumed by IC begins to attenuate at certain ambient temperature. This gradient is determined by thermal resistance
θja. Thermal resistance θja depends on chip size, power consumption, package ambient temperature, packaging condition,
wind velocity, etc., even when the same package is used. Thermal derating curve indicates a reference value measured at
a specified condition. Figure 32. shows a thermal derating curve.
0. 6
0. 5
0. 4
0. 3
0. 2
0. 1
0. 0
0 25 50 75 100 125 150
AMBIENT TEMPERATURE : Ta [℃]
Reduce by 5.4mW/℃ over 25℃.
(70.0mm×70.0mm×1.6mm FR4 glass epoxy board)
Figure 32. Thermal derating curve
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TSZ22111・15・001
15/18
TSZ02201-0H1H0B101190-1-2
28.Oct.2014 Rev.002