Datasheet

All Output Voltage Versions Electrical Characteristics (Continued)
Specifications with standard typeface are for T
J
= 25˚C, and those in boldface type apply over full Operating Temperature
Range.V
IN
= 10V unless otherwise specified.
Symbol Parameter Conditions
Typical
(Note 6)
Limit
(Note 5)
Units
T
SD_HYST
Thermal Shutdown
Hysteresis Temperature
25 ˚C
Low-side Driver (LDR) Parameters
Specifications with standard typeface are for T
J
= 25˚C, and those in boldface type apply over full Operating Temperature
Range.V
IN
= 10V unless otherwise specified.
Symbol Parameter Conditions
Typical
(Note 5)
Limit
(Note 6)
Units
V
OH
Logic High Level V
IN
= 10V 6.8
6.6
V
V(min)
V
IN
= 6.0V 6
5.8
V
V(min)
V
OL
Logic Low Level 0
0.05
V
V(max)
I
SINK
LDR Sink Current LDR Voltage = 1V 500 mA
I
SOURCE
LDR Source Current LDR Voltage = 2V 180 mA
T
RR
Rise Time C
GS
=1000pF 18 ns
T
F
Fall Time C
GS
=1000pF 7 ns
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but device parameter specifications may not be guaranteed under these conditions. For guaranteed specifications and test conditions, see
the Electrical Characteristics.
Note 2: The maximum allowable power dissipation is calculated by using P
DMAX
=(T
JMAX
−T
A
)/θ
JA
, where T
JMAX
is the maximum junction temperature, T
A
is the
ambient temperature, and θ
JA
is the junction-to-ambient thermal resistance of the specified package. The 893 mW rating results from using 150˚C, 25˚C, and
140˚C/W for T
JMAX
,T
A
, and θ
JA
respectively. A θ
JA
of 140˚C/W represents the worst-case condition of no heat sinking of the 16-pin TSSOP package. Heat sinking
allows the safe dissipation of more power. The Absolute Maximum power dissipation must be derated by 7.14 mW per ˚C above 25˚C ambient. The LM2655 actively
limits its junction temperatures to about 165˚C.
Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. The machine model is a 200pF capacitor discharged
directly into each pin.
Note 4: ESD susceptibility using the human body model is 500V for V
CB
,V
SW
, LDR, and L
DELAY
.
Note 5: Typical numbers are at 25˚C and represent the most likely norm.
Note 6: All limits guaranteed at room temperature (standard typeface) and at temperature extremes (bold typeface). All room temperature limits are 100%
production 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 7: Measured with respect to V
SW
.
Note 8: Measured while switching in closed loop with Vin = 15V.
Note 9: Average output current limit obtained using typical application circuit. This figure is dependant on the the inductor used.
Note 10: Bond wire resistance accounts for approximately 40mΩ of R
SW(ON)
.
LM2655
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