TS19601
700mA High Voltage Adjustable Current Regulator
With Enable Control
Document Number:
DS_P0000245
6
Version: D15
Thermal Consideration Information
The Maximum Power Dissipation on Current Regulator
P
D(MAX)
= V
OUT(MAX)
× I
OUT(NOM)
+ V
IN(MAX)
× I
DD
Where :
V
OUT(MAX)
= the maximum voltage on output pin;
I
OUT(NOM)
= the nominal output current;
I
DD
= the quiescent current the regulator consumes at I
OUT(NOM);
V
IN(MAX)
= the maximum input voltage.
Thermal Consideration
The TS19601 has internal power and thermal limiting circuitry designed to protect the device under overload
conditions. However, maximum junction temperature ratings should not be exceeded under continuous normal load
conditions. The thermal protection circuit of TS19601 prevents the device from damage due to excessive power
dissipation. When the device junction temperature rises to approximately 150°C, the regulator will be turned off.
When power consumption is over about 1000mW (TO-252 package, at T
A
=70°C), additional heat sink is required to
control the junction temperature below 125°C.
The junction temperature is:
T
J
= P
D
(R
θJT
+ R
θCS
+ R
θSA
) + T
A
Where :
P
D
: Dissipated power.
R
θJT
: Thermal resistance from the junction to the mounting tab of the package.
For TO-252 package, R
θJT
= 7.0°C/W.
R
θCS
: Thermal resistance through the interface between the IC and the surface on which it is mounted.
(typically, R
θCS
< 1.0°C /W)
R
θSA
: Thermal resistance from the mounting surface to ambient (thermal resistance of the heat sink).
If PC Board copper is going to be used as a heat sink, below table can be used to determine the appropriate size of
copper foil required. For multi-layered PCB, these layers can also be used as a heat sink. They can be connected
with several through-holes via.
PCB R
ºC/W
59 45 38 33 27 24 21
PCB heat sink size
500 1000 1500 2000 3000 4000 5000
