LP38690DT-3.3/NOPB National Semiconductor, LP38690DT-3.3/NOPB Datasheet - Page 13

• Manufacturer Part Number: LP38690DT-3.3/NOPB
• Description: IC REG LDO 1A 3.3V TO-252
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LP38690DT-3.3/NOPB

• Regulator Topology: Positive Fixed
• Voltage - Output: 3.3V
• Voltage - Input: Up to 10V
• Voltage - Dropout (typical): 0.65V @ 1A
• Number Of Regulators: 1
• Current - Output: 1A
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: TO-252-2, DPak (2 Leads + Tab), TO-252AA, SC-63
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Limit (min): -
• Other names: *LP38690DT-3.3; *LP38690DT-3.3/NOPB; LP38690DT-3.3

Application Hints
OUTPUT NOISE
Noise is specified in two ways: Spot Noise or Output Noise
Density is the RMS sum of all noise sources, measured at
the regulator output, at a specific frequency (measured with
a 1Hz bandwidth). This type of noise is usually plotted on a
curve as a function of frequency. Total Output Noise or
Broad-Band Noise is the RMS sum of spot noise over a
specified bandwidth, usually several decades of frequencies.
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Attention should be paid to the units of measurement. Spot
noise is measured in units µV/root-Hz or nV/root-Hz and total
output noise is measured in µV(rms)
The primary source of noise in low-dropout regulators is the
internal reference. Noise can be reduced in two ways: by
increasing the transistor area or by increasing the current
drawn by the internal reference. Increasing the area will
decrease the chance of fitting the die into a smaller package.
Increasing the current drawn by the internal reference in-
creases the total supply current (ground pin current).
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