Electrical Characteristics (Continued)
Specifications in Standard type face are for TJ = 25˚C, and in bold type face apply over the full Operating Temperature
Range (TJ = −40˚C to +125˚C). Unless otherwise specified, VIN = 12V, VISNS = VIN − 1V, and VADJ = VIN − 1.1V. Datasheet
min/max specification limits are guaranteed by design, test, or statistical analysis.
Symbol
Parameter
Conditions
Min
Typ
(Note 5)
175
Max
Unit
(Note 4)
(Note 4)
TONMIN_CL
Minimum on time in
current limit
VISNS = VADJ+0.1V
VFB = 1.0V Cload on
OUT = 1000pF
(Note 9)
ns
%VFB/∆VIN
Feedback Voltage
Line Regulation
4.5 ≤ VIN ≤ 35V
0.010
%/V
Note 1: Absolute maximum ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions for which the device is intended to
be functional, but device parameter specifications may not be guaranteed. For guaranteed specifications and test conditions, see the Electrical Characteristics.
Note 2: The maximum allowable power dissipation is a function of the maximum junction temperature, T
, the junction-to-ambient thermal resistance, θ
=
JA
J_MAX
240˚C/W, and the ambient temperature, T . The maximum allowable power dissipation at any ambient temperature is calculated using:
A
P
= (T
- T )/θ . Exceeding the maximum allowable power dissipation will cause excessive die temperature.
J_MAX A JA
D_MAX
Note 3: The human body model is a 100 pF capacitor discharged through a 1.5kΩ resistor into each pin.
Note 4: All limits are guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits are 100%
tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods. All limits are used to calculate
Average Outgoing Quality Level (AOQL).
Note 5: Typical numbers are at 25˚C and represent the most likely norm.
Note 6: The V is the trip voltage at the FB pin when PGATE switches from high to low.
FB
*
Note 7: V = I
R
ADJ
CL
CL_ADJ
Note 8: Bias current flows out from the FB pin.
Note 9: A 1000pF capacitor is connected between V and PGATE.
IN
www.national.com
4
NSC [ National Semiconductor ]
