Datasheet

LT3506/LT3506A
3
3506afc
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C, V
IN
= 5V, V
BOOST
= 8V, unless otherwise noted. (Note 2)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN(MIN)
Undervoltage Lockout
l
3.4 3.6 V
I
INQ
Quiescent Current Not Switching 3.8 4.8 mA
I
INSD
Shutdown Current V
RUNSS
= 0V 30 45 µA
V
FB
Feedback Voltage –40°C to 85°C, DHD
–40°C to 85°C, EFE
–40°C to 125°C, IFE
l
l
l
792
784
784
800
800
800
808
816
816
mV
mV
mV
I
FB
FB Pin Bias Current V
FB
= 800mV, V
C
= 0.4V
l
40 100 nA
V
FB(REG)
Reference Line Regulation V
IN
= 5V to 25V 0.005 %/V
gm
EA
Error Amp GM 350 µMhos
A
V
Error Amp Voltage Gain 400
I
VC
V
C
Source Current
V
C
Sink Current
V
FB
= 0.6V, V
C
= 0V
V
FB
= 1.2V, V
C
= 1100mV
30
30
µA
µA
V
VC(THRESH)
V
C
Switching Threshold 0.7 V
V
VC(CLAMP)
V
C
Clamp Voltage 1.9 V
f
SW
Switching Frequency LT3506
LT3506A
500
1
575
1.1
650
1.2
kHz
MHz
Switching Phase (Note 5) 180 Deg
DC Maximum Duty Cycle LT3506
LT3506A
89
78
93
88
%
%
V
FB(SWTHRESH)
Frequency Shift Threshold on FB 0.4 V
f
FOLD
Foldback Frequency V
FB
= 0V 170 kHz
I
SW
Switch Current Limit (Note 3) 2.0 2.6 3.6 A
V
SW(SAT)
Switch V
CESAT
(Note 4) I
SW
= 1A 210 mV
I
LSW
Switch Leakage Current 10 µA
V
BOOST(MIN)
Minimum Boost Voltage Above Switch I
SW
= 1A 1.5 2.5 V
I
BOOST
BOOST Pin Current I
SW
= 1A 20 30 mA
I
RUN/SS
RUN/SS Current 2.1 µA
V
RUN/SS(THRESH)
RUN/SS Threshold 0.3 0.8 V
V
FB(PGTHRESH)
V
FB
PG Threshold V
FB
Rising 720 mV
V
PG(LOW)
PG Voltage Output Low V
FB
= 640mV, I
PG
= 250µA 0.22 0.4 V
I
LPG
PG Pin Leakage V
PG
= 2V 0.1 1 µA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LT3506E/LT3506AE are guaranteed to meet performance
specifi cations from 0°C to 85°C. Specifi cations over the –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls. The LT3506I/LT3506AI are
guaranteed and tested over the full –40°C to 125°C operating temperature
range.
Note 3: Current limit is guaranteed by design and/or correlation to static
test. Slope compensation reduces current limit at high duty cycle.
Note 4: Switch V
CESAT
guaranteed by design.
Note 5: Switching phase is guaranteed by design.
ELECTRICAL CHARACTERISTICS