LM3207TL-2.53/NOPB National Semiconductor, LM3207TL-2.53/NOPB Datasheet - Page 20

• Manufacturer Part Number: LM3207TL-2.53/NOPB
• Description: IC BUCK SYNC 2.53V .65A 9USMD
• Manufacturer: National Semiconductor
• Series: PowerWise®r
• Type: Step-Down (Buck)r

Specifications of LM3207TL-2.53/NOPB

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 2.53V
• Current - Output: 650mA
• Frequency - Switching: 2MHz
• Voltage - Input: 2.7 ~ 5.5 V
• Operating Temperature: -30°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 9-MicroSMD
• For Use With: LM3207TL-2.53EV - BOARD EVAL LM3207 WCDMA/CDMALM3207TLEV - BOARD EVALUATION LM3207TL
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Other names: LM3207TL-2.53TR

www.national.com
plastic encapsulation characteristic of larger devices, it is vul-
nerable to light. Backside metalization and/or epoxy coating,
along with front-side shading by the printed circuit board, re-
duce this sensitivity. However, the package has exposed die
BOARD LAYOUT CONSIDERATIONS
Referring to Figure 4, the LM3207 has two major current loops
where pulse and ripple current flow. The loop shown in the
left hand side is most important, because pulse current shown
in Figure 4 flows in this path. The right hand side is next. The
current waveform in this path is triangular, as shown in Figure
4. Pulse current has many high-frequency components due
to fast di/dt. Triangular ripple current also has wide high-fre-
FIGURE 4. Current Loop
20
edges. Micro SMD devices are sensitive to light, in the red
and infrared range, shining on the package’s exposed die
edges.
quency components. Board layout and circuit pattern design
of these two loops are the key factors for reducing noise ra-
diation and stable operation. Other lines, such as from battery
to C1(+) and C2(+) to load, are almost DC current, so it is not
necessary to take so much care. Only pattern width (current
capability) and DCR drop considerations are needed.
20165354