TS29152 datasheet(5/8 Pages) TSC

5 / 8 page

TS29152

1.5A Ultra Low Dropout Voltage Regulator

5/5

Version: A09

Thermal Characteristics (Continue)

The next parameter which must be calculated is the maximum allowable temperature rise, TR(max). this is calculated

by the using to formula:

TR(max) = TJ(max) – TA(max)

Where: TJ(max) is the maximum allowable junction temperature, which is 125

oC for commercial grade parts.

TA(max) is the maximum ambient temperature which will be encountered in the application. Using the calculated

values for TR(max) and PD, the maximum allowable value for the junction to ambient thermal resistance, θJA, can now

be found: θJA = TR(max) / PD

Adjustable Regulator Design

The adjustable regulator versions is allow to programming the output voltage anywhere between 1.25 and the 26V

maximum operating rating of the family. Two resistors are used. Resistors can be quite large up to 1MΩ, because of

the very high input impedance and low bias current of the sense comparator, the resistor values are calculated by:

R1 = R2 * [(VOUT / 1.24) – 1]

Where is Vout the desired output voltage. Above application circuit shows component definition. Applications with

widely varying load currents may scale the resistors to draw the minimum load current required for proper operation.

Enable Input

TS29152 versions feature an enable (EN) input that allows ON/OFF control of the device. Special design allows

“zero” current drain when the device is disabled–only microamperes of leakage current flow. The EN input has

TTL/CMOS compatible thresholds for simple interfacing with logic, or may be directly tied to ≤30V. Enabling the

regulator requires approximately 20uA of current.

TS29152 Datasheet(PDF) 5 Page - Taiwan Semiconductor Company, Ltd