Datasheet
OUTPUT VOLTAGE
PROGRAMMING GUIDE
OUTPUT
VOLTAGE
R1 R2
1.8 V
2.8 V
5.0 V
0.499 MΩ
1.33 MΩ
3.16 MΩ
1 MΩ
1 MΩ
1 MΩ
GND
FB
IN OUT
V
IN
V
OUT
R
1
C
FB
R
2
TPS71501
V
OUT
+ V
REF
ǒ
1 )
R1
R2
Ǔ
0.1µF 0.47µF
R1 +
ǒ
V
OUT
V
REF
* 1
Ǔ
R2
V
OUT
+ V
REF
ǒ
1 )
R1
R2
Ǔ
TPS715xx
SLVS338Q –MAY 2001–REVISED JANUARY 2014
www.ti.com
Programming the TPS71501 Adjustable LDO Regulator
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:
(3)
where:
• V
REF
= 1.205 V typ (the internal reference voltage)
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
increases/decreases the feedback voltage and thus erroneously decreases/increases V
OUT
. The recommended
design procedure is to choose R2 = 1 MΩ to set the divider current at 1.5 μA, and then calculate R1 using
Equation 4:
(4)
Figure 16. TPS71501 Adjustable LDO Regulator Programming
Power the MSP430 Microcontroller
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 V
OUT
(TYP) APPLICATION
TPS71519 1.9 V V
OUT, MIN
> 1.800 V required by many MSP430s. Allows lowest power consumption operation.
TPS71523 2.3 V V
OUT, MIN
> 2.200 V required by some MSP430s FLASH operation.
TPS71530 3.0 V V
OUT, MIN
> 2.700 V required by some MSP430s FLASH operation.
TPS715345 3.45 V V
OUT, MIN
< 3.600 V required by some MSP430s. Allows highest speed operation.
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.
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