LTC3490 Datasheet, PDF (3/12 Pages) Linear Technology – Single Cell 350mA LED Driver

LTC3490
ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are T_A = 25°C. V_IN = 2.5V unless otherwise specified.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX
I_L(PMOS)
R_ON(PMOS)
V_IH
V_IL
I_IN
K_CTRL
R_ON(LOBAT)
V_IN(LOBAT1)
V_IN(LOBAT2)
V_IN(UVLO2)
Leakage Current, PMOS Switch
On-Resistance, PMOS Switch
Input High (CELLS)
Input High (SHDN)
Input Low (CELLS)
Input Low (SHDN)
Input Current (CTRL/SHDN, CELLS)
Control Gain, I_LED/V_CTRL
On-Resistance, LOBAT Output
Input Voltage, Low Battery, 1 Cell
Input Voltage, Low Battery, 2 Cells
Input Voltage, Undervoltage Lockout,
2 Cells
Scales Linearity with V_IN, V_IN = 1V
V_IN < V_IN(LOBAT)
V_CELLS = 0V
V_CELLS = V_IN
V_CELLS = V_IN
0.1
0.13
V_IN – 0.4
V_IN • 0.9
0.4
V_IN • 0.2
0.01
500
●
300
● 0.8
1.12
● 1.8
2.24
● 1.4
1.8
V_IN(UVLO1) Input Voltage, Undervoltage Lockout, V_CELLS = 0 V
1 Cell
● 0.7
0.9
UNITS
µA
Ω
V
V
V
V
µA
mA/V
Ω
V
V
V
V
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 LTC3490 is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C range are
assured by design, characterization and correlation with statistical process
controls.
Note 3: The LTC3490 input voltage may drop below the minimum start-up
voltage once the LED voltage has risen above 2.3V.
Note 4: This device includes overtemperature protection intended to
protect the device during momentary overload conditions. The maximum
junction temperature may be exceeded when overtemperature protection
is active. Continuous operation above the specified maximum operating
junction temperature may result in device degradation or failure.
Note 5: The Exposed Pad of the DFN package must be soldered to a
PCB pad for optimum thermal conductivity. This pad must be connected
to ground.
TYPICAL PERFOR A CE CHARACTERISTICS
Oscillator Frequency
vs Temperature
1.400
1.360
1.320
1.280
1.240
1.200
–50
0
50
TEMPERATURE (°C)
100
3490 G01
I_LED vs V_CTRL
400
350
300
250
MAXIMUM
200
150
MINIMUM
100
50
0
0
0.2 0.4 0.6
0.8
1
V_CTRL/V_IN (V)
3490 G02
I_LED vs V_IN
375
V_LED = 3.5V
350
325
300
275
250
1
1.5
2
2.5
3
V_IN (V)
3490 G03
3490fa
3