I

=

OUT(t)

C

OUT

OUT

´ dV

(t)

dt

V

OUT(t)

R

LOAD

+

IN

OUT

GND

EN

DNC

TLV759P

VOUT

VIN

FB

CIN

COUT

VEN

R2

R1

20

TLV759P

SBVS352A – APRIL 2018 – REVISED DECEMBER 2018

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8.3 Typical Application

Figure 44 shows the typical application circuit for the TLV759P. Input and output capacitances must be at least

1 µF.

Figure 44. TLV759P Typical Application

8.3.1 Design Requirements

Use the parameters listed in Table 2 for typical linear regulator applications.

Table 2. Design Parameters

PARAMETER

DESIGN REQUIREMENT

Input voltage

3.8 V

Output voltage

3.3 V, ±1%

Input current

1 A (maximum)

Output load

1-A DC

Maximum ambient temperature

70°C

8.3.2 Detailed Design Procedure

Input and output capacitors are required to achieve the output voltage transient requirements. Capacitance

values of 2.2 µF are selected to give the maximum output capacitance in a small, low-cost package; see the

Input and Output Capacitor Selection section for details.

Figure 40 illustrates the output voltage of the TLV759P. Set the output voltage using the resistor divider; see the

section for details.

8.3.2.1 Input Current

During normal operation, the input current to the LDO is approximately equal to the output current of the LDO.

During startup, the input current is higher as a result of the inrush current charging the output capacitor. Use

Equation 6 to calculate the current through the input.

where:

•

VOUT(t) is the instantaneous output voltage of the turn-on ramp

•

dVOUT(t) / dt is the slope of the VOUT ramp

•

RLOAD is the resistive load impedance

(6)

8.3.2.2 Thermal Dissipation

The junction temperature can be determined using the junction-to-ambient thermal resistance (RθJA) and the total

power dissipation (PD). Use Equation 7 to calculate the power dissipation. Multiply PD by RθJA as Equation 8

shows and add the ambient temperature (TA) to calculate the junction temperature (TJ).

PD = (IGND+ IOUT) × (VIN – VOUT)

(7)

TJ = RθJA × PD + TA

(8)