LTC3452 Datasheet, PDF (3/16 Pages) Linear Technology – Synchronous Buck-Boost MAIN/CAMERA White LED Driver

LTC3452
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are T_A = 25°C.
V_IN = PV_IN = V_OUT = 3.6V unless otherwise specified. (Note 2)
PARAMETER
CONDITIONS
MIN TYP MAX
LED_Lx Output Current Ratio (I_LEDLx/I_SETL)
(Note 6)
I_LEDLx|MAX = 20mA, V_LEDLx = 300mV
PWM Duty Cycle = 6%
1.8
2 2.16
● 1.75 2 2.21
PWM Duty Cycle = 19%
3.66 4 4.28
● 3.56 4 4.38
PWM Duty Cycle = 31%
7.32 8 8.56
● 7.12 8 8.76
PWM Duty Cycle = 44%
14.72 16 17.04
● 14.32 16 17.44
PWM Duty Cycle = 56%
29.44 32 33.92
● 28.64 32 34.56
PWM Duty Cycle = 69%
58.88 64 67.2
● 57.92 64 68.16
PWM Duty Cycle = 81%
117.12 128 134.4
● 114.56 128 137.6
PWM Duty Cycle = 94%
234.24 256 268.8
● 229.12 245 272.64
LED_Lx Output Current Matching
LED_Lx Pin Voltage
Regulated Maximum V_OUT
PMOS Switch R_ON
NMOS Switch R_ON
Forward Current Limit
(Max – Min)/[(Max + Min)/2] • 100%, I_LEDLx = 20mA,
V_LEDLx = 300mV
I_LEDLx = 20mA
V_LEDLx = V_LEDHy = 0V
Switches A and D at 100mA
Switches B and C at 100mA
Switch A
2.5
8
130
● 4.35 4.5 4.75
210
205
1000 1600 2400
Reverse Current Limit
Switch D
200
PMOS Switch Leakage
Switches A and D
–1
1
NMOS Switch Leakage
Switches B and C
–1
1
Oscillator Frequency
0.9
1
1.1
Soft-Start Time
650
UNITS
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
mA/mA
%
mV
V
mΩ
mΩ
mA
mA
µA
µA
MHz
µs
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 LTC3452E is guaranteed to meet specifications from 0°C to
70°C. Specifications over the –40°C to 85°C operating temperature range
are assured by design, characterization and correlation with statistical
process controls.
Note 3: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formula:
T_J = T_A + (P_D • θ_JA°C/W).
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
Note 5: Do not exceed 50kHz PWM frequency in the application.
Note 6: This parameter is tested in a setup which forces conditions
equivalent to those programmed by the indicated duty cycle.
3452f
3