LM3687TL-1813 NSC [National Semiconductor], LM3687TL-1813 Datasheet - Page 8

• Manufacturer Part Number: LM3687TL-1813
• Description: Step-Down DC-DC Converter with Integrated Low Dropout Regulator and Startup Mode
• Manufacturer: NSC [National Semiconductor]

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External Components, Recommended Specification
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Operating Ratings are conditions under which operation
of the device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions,
see the Electrical Characteristics tables.
Note 2: All voltages are with respect to the potential at the SGND pin.
Note 3: Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at T
= 140°C (typ.).
Note 4: For detailed soldering specifications and information, please refer to National Semiconductor Application Note 1112: Micro SMD Wafer Level Chip Scale
Package (AN-1112).
Note 5: The Human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. The machine model is a 200pF capacitor discharged
directly into each pin. (MIL-STD-883 3015.7)
Note 6: In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may have to be
derated. Maximum ambient temperature (T
dissipation of the device in the application (P
following equation: T
Note 7: Junction-to-ambient thermal resistance is highly application and board-layout dependent. In applications where high maximum power dissipation exists,
special attention must be paid to thermal dissipation issues in board design.
Note 8: Min and Max limits are guaranteed by design, test, or statistical analysis. Typical numbers are not guaranteed, but do represent the most likely norm.
Unless otherwise specified, conditions for typ. specifications are: V
Note 9: Dropout voltage is defined as the input to output voltage differential at which the output voltage falls to 100mV below the nominal output voltage.
Note 10: This specification does not apply if the battery voltage V
Note 11: The parameters in the electrical characteristic table are tested at V
refer to datasheet curves.
Note 12: The battery input voltage range recommended for ideal applications performance for the specified output voltages is given as follows: V
5.5V for 1.0V < V
Note 13: The capacitor tolerance should be 30% or better over temperature. The full operating conditions for the application should be considered when selecting
a suitable capacitor to ensure that the minimum value of capacitance is always met. Recommended capacitor type is X7R. However, dependent on application,
X5R, Y5V, and Z5U can also be used. The shown minimum limit represents real minimum capacitance, including all tolerances and must be maintained over
temperature and dc bias voltage (See capacitor section in Applications Hints)
Note 14: Refer to datasheet curves for closed loop data and its variation with regards to supply voltage and temperature. Electrical Characteristic table reflects
open loop data (FB=0V and current drawn from SW pin ramped up until cycle by cycle current limit is activated). Closed loop current limit is the peak inductor
current measured in the application circuit by increasing output current until output voltage drops by 10%.
Note 15: The DC-DC converter will only enter thermal shutdown from PWM mode. At light loads -present for PFM mode- no significant contribution to the power
dissipation is added by the DC-DC converter.
C
C
C
C
C
L
VOUT_LIN
VIN_LIN
VBATT
VOUT_DCDC
ESR
Symbol
OUT_DCDC
Output Capacitance for
linear regulator
Input Capacitance for
linear regulator
Input Capacitance for
DC-DC converter
DC-DC converter output
filter capacitor
ESR of all capacitors
Inductance
I
DCR
SAT
A-MAX
= T
< 1.8V;
Parameter
J-MAX-OP
V
– (θ
BATT
JA
A-MAX
= (V
× P
D-MAX
OUT_DCDC
D-MAX
) is dependent on the maximum operating junction temperature (T
), and the junction-to ambient thermal resistance of the part/package in the application (θ
V
V
post regulation application)
IN_LIN
OUT_DCDC
).
+1V) to 5.5V for 1.8V
is biased separately, not by
(no C
BATT
Conditions
BATT
needs to be decreased below the minimum operating limit of 2.7V.
VIN_LIN
= 3.6V and T
BATT
8
≤
= 3.6V unless otherwise specified. For performance over the input voltage range
needed for
V
OUT_DCDC
A
= 25°C.
≤
1.875V
Value
2.2
1.0
4.7
2.2
1.6
10
(Note 13)
J-MAX-OP
0.003
0.47
Min
1.5
J
= 125°C), the maximum power
= 160°C (typ.) and disengages at T
Limit
0.300
Max
200
10
JA
), as given by the
BATT
Units
mΩ
µH
µF
µF
µF
µF
= 2.7V to
Ω
A
J