TCA 3727 Infineon Technologies, TCA 3727 Datasheet - Page 22

• Manufacturer Part Number: TCA 3727
• Manufacturer: Infineon Technologies

Specifications of TCA 3727

• Packages: P-DIP-20
• Ipeak: 2 x 1.0 A
• Inhibit: Y
• Iq (typ): 20.0 µA
• Mounting: THT
• Technology: Bipolar

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
•
•
P
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Data Sheet
tot
S
saturation losses
quiescent losses
switching losses
P
P
I
I
i
i
t
t
t
t
t
T = cycle duration
d
V
V
V
V
V
V
I
= 2
D
R
p
ON
OFF
DON
DOFF
N
q
L
sat
q
satl
satuC
satuD
Fu
S
L
V
------
= duty cycle
= conducting time of chopper transistor
T
= quiescent current
= current from logic supply
= reverse current during turn-on delay
= peak reverse current
= nominal current (mean value)
=
= logic supply voltage
= supply voltage
S
= turn-ON time
= forward voltage of free-wheeling diode (D1, D2)
⎧
⎨
⎩
= turn-OFF time
= saturation voltage of sink transistor (T3, T4)
= turn-ON delay
I
= turn-OFF delay
q
i
----------------------
I
P
= saturation voltage of source transistor (T1, T2) during charge cycle
= saturation voltage of source transistor (T1, T2) during discharge cycle
D
N
sat
{
V
V
2
t
+
S
DON
satl
P
+
q
I
t
+
L
p
+ 2
d
/T
i
------------------------------
+
D
V
P
P
P
+
V
L
s
q
sat
P
i
Fu
(turn-ON / turn-OFF operations).
(quiescent current times supply voltage) and
R
4
s
(transistor saturation voltage and diode forward voltages),
(1 -
P
t
tot
ON
d
is made up of
) +
+
I
---- -
2
N
V
t
satuC
DOFF
+
22
d
t
OFF
+
V
⎫
⎬
⎭
satuD
(1 -
d
)}
Rev. 2.0, 2004-10-01
TCA 3727
(1)
(2)