lm2770sdx-12157 National Semiconductor Corporation, lm2770sdx-12157 Datasheet - Page 5

• Manufacturer Part Number: lm2770sdx-12157
• Description: High Efficiency Switched Capacitor Step-down Dc/dc Regulator With Sleep Mode
• Manufacturer: National Semiconductor Corporation

Electrical Characteristics
(Notes 2, 9) (Continued)
o
Note 7: Maximum ambient temperature (T
) is dependent on the maximum operating junction temperature (T
= 105
C), the maximum power
A-MAX
J-MAX-OP
dissipation of the device in the application (P
), and the junction-to ambient thermal resistance of the part/package in the application (θ
), as given by the
D-MAX
JA
following equation: T
= T
– (θ
x P
).
A-MAX
J-MAX-OP
JA
D-MAX
Note 8: Junction-to-ambient thermal resistance is highly application and board-layout dependent. In applications where high maximum power dissipation exists,
special care must be paid to thermal dissipation issues.
Note 9: Min and Max limits are guaranteed by design, test, or statistical analysis. Typical numbers are not guaranteed, but do represent the most likely norm.
Note 10: C
, C
, C
, and C
: Low-ESR Surface-Mount Ceramic Capacitors (MLCCs) used in setting electrical characteristics.
IN
OUT
1
2
Note 11: Efficiency is measured versus V
, with V
being swept in small increments from 3.0V to 4.2V. The average is calculated from these measurement results.
IN
IN
Weighting to account for battery voltage discharge characteristics (V
vs. Time) is not done in computing the average.
BAT
Note 12: There is a 300kΩ pull-down resistor connected internally between the EN pin and GND.
5
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