LT3008ITS8-3.3#TRPBF Linear Technology, LT3008ITS8-3.3#TRPBF Datasheet - Page 14

• Manufacturer Part Number: LT3008ITS8-3.3#TRPBF
• Description: IC REG LDO 3.3V 20MA TSOT23-8
• Manufacturer: Linear Technology

Specifications of LT3008ITS8-3.3#TRPBF

• Regulator Topology: Positive Fixed
• Voltage - Output: 3.3V
• Voltage - Input: Up to 45V
• Voltage - Dropout (typical): 0.3V @ 20mA
• Number Of Regulators: 1
• Current - Output: 20mA
• Current - Limit (min): 22mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: TSOT-23-8, TSOT-8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

LT3008 Series
APPLICATIONS INFORMATION
piezoelectric response. A piezoelectric device generates
voltage across its terminals due to mechanical stress,
similar to the way a piezoelectric accelerometer or
microphone works. For a ceramic capacitor, the stress
can be induced by vibrations in the system or thermal
transients. The resulting voltages produced can cause
appreciable amounts of noise, especially when a ceramic
capacitor is used for noise bypassing. A ceramic capacitor
produced Figure 5’s trace in response to light tapping from a
pencil. Similar vibration induced behavior can masquerade
as increased output voltage noise.
Thermal Considerations
The LT3008’s maximum rated junction temperature of
125°C limits its power-handling capability. Two components
comprise the power dissipated by the device:
1. Output current multiplied by the input/output voltage
2. GND pin current multiplied by the input voltage:
14
differential: I
I
GND
500μV/DIV
• V
V
IN
OUT
Figure 5. Noise Resulting from Tapping
on a Ceramic Capacitor
V
C
I
OUT
LOAD
OUT
OUT
= 0.6V
= 22μF
= 10μA
• (V
IN
100ms/DIV
– V
OUT
)
3008 F05
GND pin current is found by examining the GND Pin
Current curves in the Typical Performance Characteristics
section. Power dissipation is equal to the sum of the two
components listed prior.
The LT3008 regulator has internal thermal limiting designed
to protect the device during overload conditions. For
continuous normal conditions, do not exceed the maximum
junction temperature rating of 125°C. Carefully consider
all sources of thermal resistance from junction to ambient
including other heat sources mounted in proximity to
the LT3008. For surface mount devices, heat sinking is
accomplished by using the heat spreading capabilities of
the PC board and its copper traces. Copper board stiffeners
and plated through-holes can also be used to spread the
heat generated by power devices.
The following tables list thermal resistance for several
different board sizes and copper areas. All measurements
were taken in still air on 3/32" FR-4 two-layer boards with
one ounce copper.
PCB layers, copper weight, board layout and thermal vias
affect the resultant thermal resistance. Although Tables
2 and 3 provide thermal resistance numbers for 2-layer
boards with 1 ounce copper, modern multilayer PCBs
provide better performance than found in these tables.
Table 2: Measured Thermal Resistance for DC Package
*Device is mounted on the topside.
TOPSIDE*
2500mm
1000mm
225mm
100mm
50mm
COPPER AREA
2
2
2
2
2
BACKSIDE
2500mm
2500mm
2500mm
2500mm
2500mm
2
2
2
2
2
2500mm
2500mm
2500mm
2500mm
2500mm
BOARD
AREA
2
2
2
2
2
(JUNCTION-TO-AMBIENT)
THERMAL RESISTANCE
65°C/W
70°C/W
75°C/W
80°C/W
85°C/W
3008fb