Datasheet

LT3494/LT3494A
3
3494fb
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 LT3494/LT3494A 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.
PARAMETER CONDITIONS MIN TYP MAX UNITS
CTRL Pin Bias Current V
CTRL
= 0.5V, Current Flows Out of Pin
●
20 100 nA
CTRL to FB Offset V
CTRL
= 0.5V 8 15 mV
Maximum Shunt Current V
FB
= 1.3V, V
CAP
= 5V 230 μA
Note 3: Internal reference voltage is determined by fi nding V
FB
voltage
level which causes quiescent current to increase 20μA above “Not
Switching” level.
Note 4: If CTRL is overriding the internal reference, Start-Up mode occurs
when V
FB
is less then half the voltage on CTRL. If CTRL is not overriding
the internal reference, Start-Up mode occurs when V
FB
is less then half the
voltage of the internal reference.
Note 5: Current limit guaranteed by design and/or correlation to static test.
ELECTRICAL CHARACTERISTICS
The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
A
= 25°C. V
CC
= 3V, V
SHDN
= V
CC
, unless otherwise noted. (Note 2)
TYPICAL PERFORMANCE CHARACTERISTICS
Switching Frequency
vs Load Currrent
Load Regulation V
OUT
vs CTRL Voltage
LOAD CURRENT (mA)
0.1
800
SWITCHING FREQUENCY (kHz)
1000
1200
1400
1 10 100
3494 G01
600
400
200
0
LT3494
FIGURE 5 CIRCUIT
V
CC
= 3.6V
V
OUT
= 16V
LOAD CURRENT (mA)
0
V
OUT
VOLTAGE CHANGE (%)
0
1.0
40
3494 G02
–1.0
–2.0
10
20
30
5
15
25
35
2.0
–0.5
0.5
–1.5
1.5
LT3494
FIGURE 5 CIRCUIT
V
CC
= 3.6V
V
OUT
= 16V
CTRL VOLTAGE (V)
0.1
0
V
OUT
VOLTAGE (V)
5
10
15
20
0.3 0.5 0.7 0.9
3494 G03
1.1 1.3 1.5
LT3494
FIGURE 5 CIRCUIT
V
CC
= 3.6V
V
OUT
= 16V
LOAD CURRENT = 1mA
T
A
= 25°C unless otherwise noted.