L6201 - L6202 - L6203
It could be requested to drive a motor at V
S
lower
than the minimum recommended one of 12V
(See Electrical Characteristics); in this case, by
accepting a possible small increas in the R
DS (ON)
resistance of the power output transistors at the
lowest Supply Voltage value, may be a good solu-
tion the one shown in Fig. 20.
Figure 20:
L6201/1P/2/3 Used at a Supply Volt-
age Range Between 9 and 18V
Figure 21:
Typical R
Th J-amb
vs. "On Board"
Heatsink Area (L6201)
L6201
L6201PS
L6202
L6203
Figure 22:
Typical Transient R
TH
in Single Pulse
Condition (L6201)
THERMAL CHARACTERISTICS
Thanks to the high efficiency of this device, often
a true heatsink is not needed or it is simply ob-
tained by means of a copper side on the P.C.B.
(L6201/2).
Under heavy conditions, the L6203 needs a suit-
able cooling.
By using two square copper sides in a similar way
as it shown in Fig. 23, Fig. 21 indicates how to
choose the on board heatsink area when the
L6201 total power dissipation is known since:
R
Th j-amb
= (T
j max.
– T
amb max
) / P
tot
Figure 22 shows the Transient Thermal Resis-
tance vs. a single pulse time width.
Figure 23 and 24 refer to the L6202.
For the Multiwatt L6203 addition information is
given by Figure 25 (Thermal Resistance Junction-
Ambient vs. Total Power Dissipation) and Figure
26 (Peak Transient Thermal Resistance vs. Re-
petitive Pulse Width) while Figure 27 refers to the
single pulse Transient Thermal Resistance.
Figurre 23:
Typical R
Th J-amb
vs. Two "On Board"
Square Heatsink (L6202)
14/20
STMICROELECTRONICS [ STMICROELECTRONICS ]
