LTC3355_15 Datasheet, PDF (4/20 Pages) Linear Technology – 20V 1A Buck DC/DC with Integrated SCAP Charger and Backup Regulator

LTC3355
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C. V_IN = 12V unless otherwise noted. (Note 2)
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
5A Boost Regulator
I_VOUT
V_OUT Quiescent Current
V_OUT = 3.3V, No Load, In Regulation, No
l 80
160
280
µA
Switching, Burst Mode
I_SW2
SW2 Peak Current
R_NMOS
I_LEAKN
DC Max
NMOS On-Resistance
NMOS Leakage Current
Boost Maximum Duty Cycle
R_IBSTPK = 200k, PWM Mode
R_IBSTPK = 200k, Burst Mode
Boost Disabled
4.5
5
5.5
A
1.5
A
70
mΩ
–5
5
µA
88
92
98
%
V_SBOOST Boost Input Supply Voltage Range
Boost Minimum Input Supply
A_V
Boost Error Amplifier Voltage Gain
g_m
Boost Error Amplifier Transconductance
V_IBSTPK I_BSTPK Reference Voltage
R_IBSTPK I_BSTPK Set Resistor Range
Logic (MODE, EN_CHG, CPGOOD, RSTB, PFOB)
V_IL
V_IH
I_IL, I_IH
V_OL
I_OH
Input Low Logic Voltage
Input High Logic Voltage
Input Low/High Current
Output Logic Low Voltage
Logic High Leakage Current
CPGOOD Rising Threshold
CPGOOD Hysteresis
RSTB Falling Threshold
RSTB Hysteresis
RSTB Delay
V_OUT(MAX) = 4V
(Note 5)
MODE, EN_CHG
MODE, EN_CHG
MODE, EN_CHG
PFOB, CPGOOD, RSTB; Sink 100µA
PFOB, CPGOOD, RSTB; 5V
V_CAP as a % of Final Target
∆V_CAP as a % of Final Value
V_OUT as a % of Final Target
∆V_OUT as a % of Final Value
0.75
5
V
0.5
V
850
V/V
27
μS
0.775
0.825
V
200
1000
kΩ
0.4
V
1.2
V
-1
1
µA
50
mV
1
µA
90
92.5
95
%
2.5
%
90
92.5
95
%
2.5
%
250
ms
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 LTC3355 is tested under pulsed load conditions such that
T_J ≈ T_A. The LTC3355E is guaranteed to meet specifications from
0°C to 85°C junction temperature. Specifications over the –40°C to
125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LTC3355I is guaranteed over the –40°C to 125°C operating junction
temperature range. Note that the maximum ambient temperature
consistent with these specifications is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
impedance and other environmental factors. 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 = 47°C/W for the UF package.
Note 3: The LTC3355 has a thermal regulation loop that limits the
maximum junction temperature to 110°C by limiting the charger current.
Note 4: The current limit features of this part are intended to protect the
IC from short-term or intermittent fault conditions. Continuous operation
above the maximum specified pin current may result in device degradation
or failure.
Note 5: Guaranteed by design and/or correlation to static test.
Note 6: The LTC3355 has a thermal shutdown that will shut down the part
when the die temperature reaches 155°C.
3355fb
4
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