GS-D200S SGS-Thomson-Microelectronics, GS-D200S Datasheet - Page 15

• Manufacturer Part Number: GS-D200S
• Description: 2 / 2.5 A BIPOLAR STEPPER MOTOR DRIVE MODULE
• Manufacturer: SGS-Thomson-Microelectronics

P
P
The factor 1.1 takes into account the power dissi-
pation during the switching transient.
SLOW DECAY. The power dissipation during the
ON period is the same. The RECIRCULATION is
made internally through a power transistor
(V
therefore:
P
P
P
WAVE MODE. When operating in this mode the
power dissipation is given by values of FAST and
SLOW DECAY mode, because one phase is ener-
gized at any given time.
NORMAL MODE. At any given time, two windings
are always energized. The power dissipation of the
power output stage is therefore multiplied by a
factor 2.
HALF STEP. The power sequence, one-phase-on,
two-phase-on forces the power dissipation to be
1.5 times higher than in WAVE MODE when the
motor is running. In stall condition the worst case
for power dissipation is with two-phase-on i.e. a
power dissipation as in NORMAL MODE.
The following table summarizes the power dissipa-
tions of the output power stage of the GS-D200
when running for this example:
Fast Decay
Slow Decay
pw
pw
pw
pw
pw
satsink
= 1.1 [2 V
= 1.1 [2 1.8 1 0.25+2 1 1 0.75 + 0.5 1]
= 1.1 [0.9 + 1.5 + 0.5] = 3.19 W
= 1.1 [2 1.8 1 0.25 + (1.8 + 1) 1 0.75]
= 1.1 [0.9 + 2.1] = 3.3 W
) and a diode. The power dissipation is,
sat
3.19 W
3.30 W
I
Wave
ph
D.C.+(V
sat
Normal
6.38 W
6.60 W
+V
d
) I
ph
(1-D.C.)]
Half Step
6.38 W
6.60 W
D200 :
P
In this example, for slow decay and normal mode
P
T
maximum allowed case temperature, as in this
example, an external heat-sink is required and the
thermal resistance can be calculated according to:
Rth
and then
Rth
The following table gives the thermal resistance of
some commercially available heath-sinks that fit on
the GS-D200 module.
Manufacturer Part Number R
case
Thermalloy
Thermalloy
Thermalloy
Fischer
Assman
Assman
tot
tot
The case temperature can now be calculated:
Calculate the total power dissipation for the GS-
If the calculated case temperature exceeds the
tot
hs
= P
= 1.1 + 6.6 = 7.7 W
= T
logic
T
Rth
Rth Rth
amb
cmax
+ P
+ (P
P
Rth
tot
pw
V5440
V5382
SK18
6177
6152
6111
Tamb
tot
tot
tot
R
th
5
5 3.9
) = 55 + (7.7 5) = 93.5 C
85
3.9
GS-D200/GS-D200S
7.7
th
( C/W)
10
55
3
4
3
4
4
17.7 C
3.9 C
Mounting
Horizontal
Horizontal
Vertical
Vertical
Vertical
Vertical
15/17