TS29152_13 Datasheet, PDF (4/8 Pages) Taiwan Semiconductor Company, Ltd – 1.5A Ultra Low Dropout Voltage Regulator

TS29152
1.5A Ultra Low Dropout Voltage Regulator
Function Description
The TS29152 is high performance with low dropout voltage regulator suitable for moderate to high current and
voltage regulator application. Its 350mA(typ) dropout voltage at full load and over temperature makes it especially
valuable in battery power systems and as high efficiency noise filters in post regulator applications. Unlike normal
NPN transistor design, where the base to emitter voltage drop and collector to emitter saturation voltage limit the
minimum dropout voltage, dropout performance of the PNP output of these devices is limited only by low V_CE
saturation voltage.
The TS29152 is fully protected from damage due to fault conditions. Linear current limiting is provided. Output
current during overload conditions is constant. Thermal shutdown the device when the die temperature exceeds the
maximum safe operating temperature. Transient protection allows device survival even when the input voltage
spikes above and below nominal. The output structure of these regulators allows voltages in excess of the desired
output voltage to be applied without reverse current flow.
Capacitor Requirement
The TS29152 requires an output capacitor to maintain stability and improve transient response is necessary. The
value of this capacitor is dependent upon the output current, lower currents allow smaller capacitors. TS29152
regulators are stable with the 10uF minimum capacitor value at full load. Where the regulator is powered from a
source with high AC impedance, a 0.1uF capacitor connected between input and ground is recommended. The
capacitor should have good characteristics to above 250KHz. The capacitance values will be help to improved
transient response, ripple rejection and output noise.
Minimum Load Current
The TS29152 is specified between finite loads. If the output current is too small leakage currents dominate and the
output voltage rises. A 10mA minimum load current swamps any expected leakage current across the operating
temperature range.
Thermal Characteristics
TS29152 linear regulators are simple to use, the most complicated design parameters to consider are thermal
characteristics, thermal design requires the following application specification parameters:
* Maximum ambient temperature, Ta
* Output current, I_OUT
* Output voltage, V_OUT
* Input voltage, V_IN
We calculate the power dissipation of the regulator from these numbers and the device parameters from this data
sheet. A heatsink may be required depending on the maximum power dissipation and maximum ambient
temperature of the application. Under all possible operating conditions, the junction temperature must be within the
range specified under absolute maximum ratings. To determine if the heatsink is required, the power dissipated by
the regulator, P_D must be calculated.
The below formula shows the voltages and currents for calculating the P_D in the regulator:
I_IN = I_L / I_G
P_D = (V_IN - V_OUT) * I_L + (V_IN) * I_G
Ex. P_D = (3.3V-2.5V) * 0.5A + 3.3V * 11mA
= 400mW + 36mW
= 436mW
Remark: I_L is output load current,
I_G is ground current.
V_IN is input voltage
V_OUT is output voltage
4/8
Version: B13