LTC3815_15 Datasheet, PDF (5/42 Pages) Linear Technology – 6A Monolithic Synchronous DC/DC Step-Down Converter with Digital Power System Management

LTC3815
Electrical Characteristics The l denotes the specifications which apply over the specified operating
junction temperature range, V_IN = 3.3V unless otherwise noted. (Note 2)
SYMBOL
PARAMETER
CONDITIONS
MIN TYP
MAX
UNITS
Temperature Readback
N
Resolution
LSB Step Size
9
Bits
1
°C
V_F/S
Full Scale Temperature
T_TUE
Total Unadjusted Error
t_CONVERT
Conversion Time
PMBus Interface Parameters
±256
°C
±3
°C
40
ms
V_IH, SDA, SCL
V_IL, SDA, SCL
I_IH, SDA, SCL
V_{OL, SDA}
V_{OL, ALERT}
f_SCL
t_BUF
Input High Voltage
Input Low Voltage
Input Leakage Current
Output Low Voltage (SDA)
Output Low Voltage (ALERT)
Serial Bus Operating Frequency
Bus Free Time Between Stop and Start
Condition
0V ≤ V_PIN ≤ 5.5V
I_SDA = 3mA
I_ALERT = 1mA
2.1
V
0.8
V
–5
5
µA
0.4
V
0.4
V
10
400
kHz
1.3
µs
t_{HD_SDA}
t_{SU_SDA}
t_{SU_STO}
t_{HD_DAT(OUT)}
t_{HD_DAT(IN)}
t_{SU_DAT}
t_LOW
t_HIGH
t_{TIMEOUT_SMB}
Hold Time After (Repeated) Start Condition
Repeated Start Condition Setup Time
Stop Condition Setup Time
Data Hold Time
Input Data Hold Time
Data Set-Up Time
Clock Low Period
Clock High Period
Stuck PMBus Timer
Measured from last PMBus start
event
0.6
µs
0.6
µs
0.6
µs
300
900
ns
0
ns
100
ns
1.3
10000
µs
0.6
µs
30
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 LTC3815 is tested under pulsed load conditions such that T_J ≈ T_A.
The LTC3815E 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 LTC3815I 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.
Note 3: The junction temperature (T_J, in °C) is calculated from the ambient
temperature (T_A, in °C) and power dissipation (PD, in Watts) according to
the formula:
T_J = T_A + (PD • θ_JA)
where θ_JA (in °C/W) is the package thermal impedance.
Note 4 : The dynamic input supply current is higher due to power
MOSFET gate charging (Q_G × f_OSC). See applications Information for more
information.
Note 5: The LTC3815 is tested in a feedback loop that servos V_FB to a
referenced voltage with the I_TH pin forced to a voltage between 0.6V and
1V.
Note 6: Guaranteed by design, not subject to test.
Note 7: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum junction temperature
may impair device reliability or permanently damage the device.
Note 8: The LTC3815 uses valley current mode control so the current
limits specified correspond to the valley of the inductor current waveform.
Maximum load current is higher and equals the valley current limit I_LIM
plus one half of the inductor ripple current.
Note 9: The maximum input and output voltage is 5.5V.
Note 10: Total output accuracy is the sum of the tolerances of I_REF,
R_{REF(EXTERNAL)}, ∆V_OUT,OFFSET, and ∆I_REF,LINE • ∆V_IN.
3815p
For more information www.linear.com/LTC3815
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