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Programming the TPS71501 Adjustable LDO Regulator

V

1 )

R1

R2

(3)

R1 +

V

OUT

V

REF

* 1

R2

(4)

OUTPUT VOLTAGE

PROGRAMMING GUIDE

OUTPUT

VOLTAGE

R1

R2

1.8 V

2.8 V

5.0 V

0.499 M

Ω

1.33 M

Ω

3.16 M

Ω

1 M

Ω

1 M

Ω

1 M

Ω

GND

FB

IN

OUT

V

IN

V

OUT

R

1

C

FB

R

2

TPS71501

V

1 )

R1

R2

0.1

µF

0.47

µF

Power the MSP430 Microcontroller

TPS715xx

SLVS338O – MAY 2001 – REVISED JUNE 2007

APPLICATION INFORMATION (continued)

The output voltage of the TPS71501 adjustable regulator is programmed using an external resistor divider as

shown in Figure 16. The output voltage operating range is 1.2 V to 15 V, and is calculated using:

where:

• V

Resistors R1 and R2 should be chosen for approximately 1.5-

µA divider current. Lower value resistors can be

used for improved noise performance, but the solution consumes more power. Higher resistor values should be

avoided as leakage current into/out of FB across R1/R2 creates an offset voltage that artificially

design procedure is to choose R2 = 1 M

Ω to set the divider current at 1.5 µA, and then calculate R1 using

Equation 4:

Figure 16. TPS71501 Adjustable LDO Regulator Programming

Several versions of the TPS715xx are ideal for powering the MSP430 microcontroller. Table 2 shows potential

applications of some voltage versions.

Table 2. Typical MSP430 Applications

DEVICE

APPLICATION

TPS71519

1.9 V

TPS71523

2.3 V

TPS71530

3.0 V

TPS715345

3.45 V

The TPS715xx family offers many output voltage versions to allow designers to minimize the supply voltage for

the processing speed required of the MSP430. This minimizes the supply current consumed by the MSP430.

8

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