Texas Instruments LP592201DSC, User Manual, Page: 4 / 13

Setup
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4 SNVU532 – November 2016
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LP592201EVM User Guide
1.3 Operation
For proper operation of the LP592201EVM, the J3 terminals must be properly configured. The
recommended jumper setting is:
J3 shunt is across the center and ON pins.
In this configuration, the device powers up when power is applied at the IN terminal.
1.4 Options
The LP592201EVM has some assorted unpopulated footprints that some users may find useful:
• Footprint for an optional input capacitor at C1 (1206)
• Footprints for optional output capacitor at C2 (1206)
• Footprints for optional SMA connectors (Emerson 142-0701-851, or equivalent) at VIN (J2) and VOUT
(J1) for noise or PSRR testing.
2 Changing the Output Voltage
The LP592201 EVM uses R1 and R2 to set the output voltage to 1.8 V. It is possible to change the output
voltage within the range of 500 mV to 5.0V by changing only R1 to an appropriate value while keeping R2
at the installed value of 12.4 k
Ω
.
The R1 value for a desired output voltage can be found by using Equation 1 :
R1 = ((V
OUT
- V
FB
) x R2) / V
FB
)
where
• V
OUT
is the desired output voltage
• R2 is the installed value of 12.4 k Ω
• V
FB
is 500 mV (1)
(1)
Default values
Table 2.
TARGET V
OUT
R1 VALUE R2 VALUE Typical V
OUT
ERROR
0.50 V 0 Ω 12.4 k Ω 0.500 V 0 %
0.80 V 7.50 k
Ω
12.4 k
Ω
0.802 V 0.30 %
1.00 V 12.4 k Ω 12.4 k Ω 1.000 V 0 %
1.20 V 17.4 k Ω 12.4 k Ω 1.202 V 0.13 %
1.80 V
(1)
32.4 k Ω
(1)
12.4 k Ω
(1)
1.806 V 0.36 %
2.50 V 49.9 k Ω 12.4 k Ω 2.512 V 0.48 %
3.00 V 61.9 k
Ω
12.4 k
Ω
2.996 V –0.13 %
3.30 V 69.8 k Ω 12.4 k Ω 3.315 V 0.44 %
4.00 V 86.6 k Ω 12.4 k Ω 3.992 V –0.20 %
5.00 V 113 k Ω 12.4 k Ω 5.056 V 1.12 %
By changing both R1 and R2 values it may be possible to achieve better accuracy in some cases. It is
recommenced that the value for the lower resistor, R2, be no more than 100 k
Ω .
If the output voltage is set to 800 mV, or less, the output capacitance needs to be increased in order to
maintain stability. A C
OUT
value of 47 µF is recommended. Since the applied DC voltage is low, the de-
rating of the capacitance value due to the applied DC voltage is not a meaningful consideration. One
possible capacitor that could be used is:
Murata: 47 µF, ±10%, 6.3V, X7R, 1210; GRM32ER70J476KE20L