Diodes ZXBM2003 - Manual (Page 9)

When driving fans with bipolar transistors, at higher
voltages it may be necessary to provide extra noise
protection by the addition of a diode from the driver
collector to Gnd on each phase. This prevents negative
voltage excursions from the windings affecting
operation. See Figure 3 right, showing the placement
of these diodes. It should be noted that these are not
required for the MOSFET solution in Figure 2 as the
diodes are inherent in the MOSFET structure.
Zetex provide a variety of suitable power transistors for
using with the ZXBM200x series of 2-phase DC
brushless motor pre-drivers and suitable devices
sufficient for a range of applications are given in the
following table.
ZXBM2001
ZXBM2002 ZXBM2003
S E M I C O N D U C T O R S
ISSUE 4 - OCTOBER 2004
9
Figure 3
TYPICAL APPLICATION (ZXBM2001) illustrating addition of Clamp
diodes.
Bipolar Types V
CEO
(V) I
C
(A) min H
FE
@ I
C
V
CE(sat)
max(mV)
@ I
C
& I
B
Package
FZT1053A 75 4.5 300 @ 0.5A 200 @ 1A, 10mA SOT223
FZT851 60 6 100 @ 2A 100 @ 1A, 10mA SOT223
FZT853 100 6 100 @ 2A 175 @ 1A, 100mA SOT223
FZT855 150 4 100 @ 1A 65 @ 0.5A, 50mA SOT223
ZXT13N50DE6 50 4 300 @ 1A 100 @ 1A, 10mA SOT23-6
SUMMARY TABLE OF SUITABLE DEVICES
MOSFET Types BV
DSS
(V) I
D
(A) I
PEAK
(A)
(Pulsed)
R
DS(on)
max(m )
@ V
GS
Package
ZXMN3A04DN8
2 3 30 7.6 25 20 @ 10V SO8
ZXMN6A09DN8
2 3 60 5 17.6 45 @ 10V SO8
ZXMN6A11Z
1 60 3.8 10 140 @ 10V SOT89
ZXMN6A11G 60 3.8 10 140 @ 10V SOT223
ZXMN10A11G
2 4 100 1.9 5.9 600 @ 10V SOT223
Notes:
1
Contact your nearest Zetex office for further details and technical enquiries.
2
Dual device
3
Provisional information
4
Advanced information