PBL 3717/2
Switching frequency
PD (W)
PD (W)
The motor inductance, together with the
pulse time, toff , determines the switching
frequency of the current regulator. The
choice of motor may then require other
values on the RT , CT components than
those recommended in figure7, to obtain
a switching frequency above the audible
range. Switching frequencies above 40
kHz are not recommended because the
current regulation can be affected.
5
4
With Staver V8 (37.5
4.0
3.0
2.0
With Staver V7 (27.5
PCB heatsink (40
°
C/W)
3
2
1
°
°
C/W)
C/W)
1.0
0
Sensor resistor
0
0
The RS resistor should be of a non-
.20
.60
.40IM (A)
.80
1.0
50
100
150
inductive type, power resistor. A 1.0 ohm
resistor, tolerance ≤ 1%, is a good choice
for 415 mA max motor current at VR = 5V.
TAmb (°C)
Figure 13. Typical power dissipation vs.
motor current.
Figure 14. Allowable power dissipation
vs. ambient temperature.
Thepeak motor current, im , can be
calculated by using the formulas:
im = (VR • 0.083) / RS [A], at 100% level
im = (VR • 0.050) / RS [A], at 60% level
im = (VR • 0.016) / RS [A], at 20% level
18,5 mm
Ordering Information
Package
Part No.
PBL 3717/2NS
PBL 3717/2QNS
PBL 3717/2QNT
PBL 3717/2SOS
PBL 3717/2SOT
DIP Tube
PLCC Tube
PLCC Tape & Reel
SO Tube
38.0 mm
38.0 mm
SO Tape & Reel
Figure 15. Heatsinks, Staver, type V7 and V8 by Columbia-Staver UK.
Thermal resistance [°C/W]
90
Information given in this data sheet is believed to be
accurate and reliable. However no responsibility is
assumed for the consequences of its use nor for any
infringement of patents or other rights of third parties
which may result from its use. No license is granted
by implication or otherwise under any patent or
patent rights of Ericsson Components. These
products are sold only according to Ericsson
Components' general conditions of sale, unless
otherwise confirmed in writing.
16-pin
DIP
80
70
60
50
20-pin
SO
Specifications subject to change
without notice.
40
1522-PBL 3717/2 Uen Rev.E
© Ericsson Components AB 1999
30
5
10
15
20
25
30
35
PCB copper foil area [cm2 ]
28-pin
PLCC
PLCC package
DIP and SO package
Ericsson Components AB
SE-164 81 Kista-Stockholm, Sweden
Telephone: +46 8 757 50 00
Figure 16. Copper foil used as a heatsink.
8
ERICSSON [ ERICSSON ]
