2.0A Low Output Voltage Ultra LDO Regulator
TJ2132
temperature of application. With respect to the applied package, the maximum output current of 2A may
be still undeliverable due to the restriction of the power dissipation of TJ2132. Under all possible
conditions, the junction temperature must be within the range specified under operating conditions.
The temperatures over the device are given by:
TC = TA + PD X θCA
TJ = TC + PD X θJC
TJ = TA + PD X θJA
where TJ is the junction temperature, TC is the case temperature, TA is the ambient temperature, PD is the
total power dissipation of the device, θCA is the thermal resistance of case-to-ambient, θJC is the thermal
resistance of junction-to-case, and θJA is the thermal resistance of junction to ambient.
The total power dissipation of the device is given by:
PD = PIN – POUT = {(VIN X IIN)+(VBIAS X IBIAS)} – (VOUT X IOUT
)
where IGND is the operating ground current of the device which is specified at the Electrical Characteristics.
The maximum allowable temperature rise (TRmax) depends on the maximum ambient temperature (TAmax
of the application, and the maximum allowable junction temperature (TJmax):
)
TRmax = TJmax – TAmax
The maximum allowable value for junction-to-ambient thermal resistance, θJA, can be calculated using the
formula:
θJA = TRmax / PD
TJ2132 is available in SOP8-PP packages. The thermal resistance depends on amount of copper area or
heat sink, and on air flow.
If proper cooling solution such as heat sink, copper plane area, or air flow is applied, the maximum
allowable power dissipation could be increased. However, if the ambient temperature is increased, the
allowable power dissipation would be decreased.
Aug. 2014 – Rev.1.1.3
12
HTC
HTC [ HTC KOREA TAEJIN TECHNOLOGY CO. ]
