TLE4729-G INFINEON [Infineon Technologies AG], TLE4729-G Datasheet - Page 22

• Manufacturer Part Number: TLE4729-G
• Description: 2-Phase Stepper-Motor Driver Bipolar-IC
• Manufacturer: INFINEON [Infineon Technologies AG]

Calculation of Power Dissipation
The total power dissipation
The following equations give the power dissipation for chopper operation without phase
reversal.
This is the worst case, because full current flows for the entire time and switching losses
occur in addition.
P
where
I
I
i
i
t
t
t
t
t
T
d
V
V
V
V
V
Data Sheet
D
R
p
ON
OFF
DON
DOFF
N
q
tot
satl
satuC
satuD
Fu
S
= 2
Saturation losses
Quiescent losses
Switching losses
= Nominal current (mean value)
= Quiescent current
= Reverse current during turn-on delay
= Peak reverse current
= Conducting time of chopper transistor
= Turn-ON time
= Turn-OFF time
= Turn-ON delay
= Turn-OFF delay
= Cycle duration
= Duty cycle
= Saturation voltage of sink transistor (TX3, TX4)
= Saturation voltage of source transistor (TX1, TX2) during charge cycle
= Saturation voltage of source transistor (TX1, TX2) during discharge cycle
= Forward voltage of free-wheeling diode (DX1, DX2)
= Supply voltage
P
sat
+
P
P
P
P
q
sat
q
q
+ 2
t
p
V
------ -
/
=
P
T
P
P
T
S
s
I
I
q
sat
ì
í
î
N
q
P
i
------------------------ -
s
{
D
P
V
V
tot
satI
(transistor saturation voltage and diode forward voltages),
(quiescent current times supply voltage) and
(turn-ON / turn-OFF operations).
S
2
t
DON
is made up of
d
+
+
------------------------------------- -
V
i
D
Fu
+
22
(1 –
i
R
4
d
) +
t
ON
V
+
satuC
I
-----
2
N
t
DOFF
d
+
V
+
satuD
t
OFF
(1 –
ü
ý
þ
TLE 4729 G
d
2001-04-09
)}