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Voltage Regulators

LDO voltage regulator 3.3volts 200mA+ 1% accuracy SOT-89

ReferencePackageValueQuantityRatingNote
U401SOT-893.3volt LDO1200mA+>=2% accuracy

3.3volt power supply for the main components. Should support 150mA minimum, 2% or better accuracy, short circuit protection, thermal shutdown function, drop out < 1volt, compatible with ceramic capacitors.

Example, can be any equivalent part:

Adjustable LDO VREG with 0.8v to 5.0v output SOT-23-5

v

ReferencePackageValueQuantityRatingNote
U403SOT-23-5AP2127K-ADJTRG11

Example:

MCP1824 was used for development, but it is more expensive and harder to source than the AP2127.

tip

If no part can be sourced, a common 1.25V-5V adjustable regulator can be used with the correct resistor values (see calculations spreadsheet). The Bus Pirate will lose features though. The output range will be limited to 1.25volts to 5volts, instead of 0.8volts to 5volts.

Reference voltage configuration

PartIdeal ValueClosest Value
R403R404R405R403R404R405
MCP182477.96K99.22K10K78K100K10K
AP2127103.13K131.25K33K102K133K33K
caution

MCP1824 and AP2127 are equivalent, but have different reference voltages. R403/R404/R405 need to match the regulator as shown in the table.