LTC3122_15 Datasheet, PDF (3/26 Pages) Linear Technology – 15V, 2.5A Synchronous Step-Up DC/DC Converter with Output Disconnect

LTC3122
Electrical Characteristics The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C (Note 3). V_IN = 3.6V, V_OUT = 12V, RT = 57.6k unless otherwise noted.
PARAMETER
CONDITIONS
MIN. TYP MAX UNITS
Minimum Start-Up Voltage
Input Voltage Range
Output Voltage Adjust Range
V_OUT = 0V
After V_OUT ≥ 2.2V
l
1.7
1.8
V
l 0.5
5.5
V
l 2.2
15
V
Feedback Voltage
l 1.178 1.202 1.225
V
Feedback Input Current
Quiescent Current, Shutdown
Quiescent Current, Active
Quiescent Current, Burst
V_FB = 1.4V
V_SD = 0V, V_OUT = 0V, Not Including Switch Leakage
V_C = 0V, Measured On V_IN, Non-Switching
Measured on V_IN, V_FB > 1.4V
Measured on V_OUT, V_FB > 1.4V
1
50
nA
0.01
1
µA
500
700
µA
25
40
µA
10
20
µA
N-channel MOSFET Switch Leakage Current
P-channel MOSFET Switch Leakage Current
N-channel MOSFET Switch On-Resistance
V_SW = 15V, V_OUT = 15V, V_C = 0V
V_SW = 0V, V_OUT = 15V, V_SD = 0V
l
0.1
30
µA
l
0.1
70
µA
0.121
Ω
P-channel MOSFET Switch On-Resistance
0.188
Ω
N-channel MOSFET Current Limit
l 2.5
3.5
4.5
A
Maximum Duty Cycle
Minimum Duty Cycle
Switching Frequency
V_FB = 1.0V
V_FB = 1.4V
l 90
94
%
l
0
%
l 0.85
1
1.15
MHz
SYNC Frequency Range
l 0.1
3
MHz
PWM/SYNC Input High
PWM/SYNC Input Low
PWM/SYNC Input Current
CAP Clamp Voltage
V_CC Regulation Voltage
Error Amplifier Transconductance
V_PWM/SYNC = 5.5V
V_OUT > 6.1V, Referenced to V_OUT
V_IN < 2.8V, V_OUT > 5V
l 0.9 •V_CC
V
l
0.1•V_CC
V
0.01
1
µA
–5.2
–5.6 –6.0
V
4
4.25
4.5
V
l 70
95
120
µS
Error Amplifier Output Current
±25
µA
Soft-Start Time
10
ms
SD Input High
l 1.6
V
SD Input Low
l
0.25
V
SD Input Current
V_SD = 5.5V
1
2
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: Voltage transients on the SW pin beyond the DC limit specified in
the Absolute Maximum Ratings are non-disruptive to normal operations
when using good layout practices, as shown on the demo board or
described in the data sheet or application notes.
Note 3: The LTC3122 is tested under pulsed load conditions such that
T_A ≈ T_J. The LTC3122E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3122I is guaranteed
to meet specifications over the full –40°C to 125°C operating junction
temperature range. The LTC3122H is guaranteed to meet specifications
over the full –40°C to 150°C operating junction range. The junction
temperature (T_J in °C) is calculated from the ambient temperature (T_A in
°C) and power dissipation (P_D in Watts) according to the formula: T_J = T_A
+ (P_D • θ_JA) where θ_JA is the thermal impedance of the package.
Note 4: The LTC3122 includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 150°C when overtemperature shutdown is active.
Continuous operation above the specified maximum operating junction
temperature may result in device degradation or failure.
Note 5: Failure to solder the exposed backside of the package to the PC
board ground plane will result in a thermal impedance much higher than
the rated package specifications.
For more information www.linear.com/LTC3122
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