LTC3605A_15 Datasheet, PDF (3/22 Pages) Linear Technology – 20V, 5A Synchronous Step-Down Regulator

LTC3605A
Electrical Characteristics The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_J ≈ T_A = 25°C (Note 2). V_IN = 12V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
I_LIM
Positive Inductor Valley Current Limit
Negative Inductor Valley Current Limit
5
6
7.5
A
–5
A
R_TOP
R_BOTTOM
V_UVLO
V_RUN
V_INTVCC
DV_INTVCC
OV
Top Power NMOS On-Resistance
Bottom Power NMOS On-Resistance
INTV_CC Undervoltage Lockout
Threshold
Run Threshold 2 (I_Q ≥ 1mA)
Run Threshold 1 (I_Q ≥ 100µA)
Internal V_CC Voltage
INTV_CC Load Regulation
Output Overvoltage
PGOOD Upper Threshold
INTV_CC = 3.3V
INTV_CC = 3.3V
INTV_CC Falling
INTV_CC Hysteresis (Rising)
RUN Rising
RUN Rising
4V < V_IN < 20V
I_LOAD = 0mA to 20mA
V_FB Rising
70
150
mΩ
35
60
mΩ
2.4
2.6
2.8
V
0.25
V
1.1
1.2
1.3
V
0.45
0.6
0.75
V
3.2
3.3
3.4
V
0.5
%
7
10
13
%
UV
Output Undervoltage
PGOOD Lower Threshold
V_FB Falling
–13
–10
–7
%
DV_FB(HYS)
R_PGOOD
I_PGOOD
I_TRACK/SS
f_OSC
CLKIN
PGOOD Hysteresis
PGOOD Pull-Down Resistance
PGOOD Leakage
TRACK Pull-Up Current
Oscillator Frequency
CLKIN Threshold
V_{VIN_OV} V_IN Overvoltage Lockout Threshold
V_FB Returning
0.54V < V_FB < 0.66V
R_T = 162k
CLKIN V_IL
CLKIN V_IH
V_IN Rising
V_IN Falling
1.5
%
12
25
Ω
2
µA
2.5
4
µA
l 0.85
1
1.2
MHz
0.3
V
1
V
22.8
23.5
24.2
V
20.8
21.5
22.1
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. Absolute Maximum Ratings are those values
beyond which the life of a device may be impaired.
Note 2: The LTC3605A is tested under pulsed load conditions such that
T_J ≈ T_A. The LTC3605AE (E-grade) 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
LTC3605AI (I-grade) is guaranteed over the full –40°C to 125°C operating
temperature range.
The junction temperature (T_J) is calculated from the ambient temperature
(T_A) and power dissipation (P_D) according to the formula:
T_J = T_A + (P_D • θ_JA°C/W)
where θ_JA is the package thermal impedance. Note that the maximum
ambient temperature is determined by specific operating conditions
in conjunction with board layout, the rated thermal package thermal
resistance and other environmental factors.
Note 3: Dynamic supply current is higher due to the internal gate charge
being delivered at the switching frequency.
Note 4: The LTC3605A is tested in a feedback loop that adjusts V_FB to
achieve a specified error amplifier output voltage (ITH).
Note 5: T_J is calculated from the ambient temperature T_A and
power dissipation as follows: T_J = T_A + P_D • (37°C/W). See Thermal
Considerations section.
Note 6: 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 operating junction
temperature may impair device reliability.
For more information www.linear.com/LTC3605A
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