LP3907 Datasheet, PDF (7/58 Pages) National Semiconductor (TI) – Dual High-Current Step-Down DC/DC and Dual Linear Regulator with I2C Compatible Interface

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LP3907
SNVS511S – JUNE 2007 – REVISED APRIL 2016
7.4 Thermal Information
See ^{(1) (2) (3)}
THERMAL METRIC⁽⁴⁾
LP3907
RTW
YZR
UNIT
24 PINS
25 PINS
R_θJA
R_θJC(top)
R_θJB
ψ_JT
ψ_JB
R_θJC(bot)
Junction-to-ambient thermal resistance
Junction-to-case (top) thermal resistance
Junction-to-board thermal resistance
Junction-to-top characterization parameter
Junction-to-board characterization parameter
Junction-to-case (bottom) thermal resistance
32.7
58.7
°C/W
31.2
0.3
°C/W
11.2
8.0
°C/W
0.2
0.6
°C/W
11.2
8.0
°C/W
1.4
N/A
°C/W
(1) 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 in board design.
(2) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at T_J = 160°C (typical) and
disengages at T_J = 140°C (typical)
(3) 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_A-MAX) is dependent on the maximum operating junction temperature (T_J-MAX-OP =
125°C), the maximum power dissipation of the device in the application (P_D-MAX), and the junction-to-ambient thermal resistance of the
part/package in the application (R_θJA), as given by the following equation: T_A-MAX = T_J-MAX-OP − (R_θJA × P_D-MAX).
(4) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report, SPRA953.
7.5 General Electrical Characteristics
Unless otherwise noted, V_IN = 3.6 V and T_J = 25°C.^(1)(2)(3)(4)
PARAMETER
TEST CONDITIONS
I_Q
V_POR
T_SD
T_SDH
UVLO
VINLDO12 shutdown current
Power-on reset threshold
Thermal shutdown threshold
Thermal shutdown hysteresis
Undervoltage lockout
V_IN = 3.6 V
V_DD falling edge⁽⁴⁾
Rising
Falling
MIN TYP MAX UNIT
3
µA
1.9
V
160
°C
20
°C
2.9
V
2.7
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) All voltages are with respect to the potential at the GND pin.
(3) This specification is ensured by design.
(4) VPOR is voltage at which the EPROM resets. This is different from the UVLO on VINLDO12, which is the voltage at which the
regulators shut off, and is also different from the nPOR function, which signals if the regulators are in a specified range.
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