LTC3637_15 Datasheet, PDF (3/26 Pages) Linear Technology – 76V, 1A Step-Down Regulator

LTC3637
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C (Note 2). V_IN = 12V, unless otherwise noted.
SYMBOL
PARAMETER
Input Supply (V_IN)
V_IN
Input Voltage Operating Range
V_OUT
Output Voltage Operating Range
UVLO
V_IN Undervoltage Lockout
CONDITIONS
V_IN Rising
V_IN Falling
Hysteresis
MIN TYP MAX
4
76
0.8
V_IN
l 3.45 3.65 3.85
l 3.30
3.5
3.70
150
UNITS
V
V
V
V
mV
I_Q
DC Supply Current (Note 5)
Active Mode
Sleep Mode
Shutdown Mode
No Load
RUN = 0V
165
350
µA
12
20
µA
3
10
µA
RUN and OVLO Pin Threshold Voltage
Rising
Falling
Hysteresis
1.17 1.21 1.25
V
1.06 1.10 1.14
V
110
mV
RUN Pin Leakage Current
Output Supply (V_FB)
Feedback Comparator Threshold Voltage
(Adjustable Output)
RUN = 1.3V
V_FB Rising, V_PRG1 = V_PRG2 = 0V
LTC3637E, LTC3637I
LTC3637H, LTC3637MP
–10
0
10
nA
l 0.792 0.800 0.808
V
l 0.788 0.800 0.812
V
Operation
Feedback Comparator Hysteresis
(Adjustable Output)
Feedback Pin Current
Feedback Comparator Threshold Voltages
(Fixed Output)
Feedback Voltage Line Regulation
V_FB Falling, V_PRG1 = V_PRG2 = 0V
V_FB = 1V, V_PRG1 = 0V, V_PRG2 = 0V
V_FB Rising, V_PRG1 = SS, V_PRG2 = 0V
V_FB Falling, V_PRG1 = SS, V_PRG2 = 0V
V_FB Rising, V_PRG1 = 0V, V_PRG2 = SS
V_FB Falling, V_PRG1 = 0V, V_PRG2 = SS
V_FB Rising, V_PRG1 = V_PRG2 = SS
V_FB Falling, V_PRG1 = V_PRG2 = SS
V_IN = 4V to 76V
Peak Current Comparator Threshold
Power Switch On-Resistance
Switch Pin Leakage Current
Soft-Start Pin Pull-Up Current
Internal Soft-Start Time
I_SET Floating
100k Resistor from I_SET to GND
I_SET Shorted to GND
I_SW = –200mA
V_IN = 65V, SW = 0V
SS Pin < 2.5V
SS Pin Floating
l 2.5
5
7
mV
–10
0
10
nA
l 4.940 5.015 5.090
V
l 4.910 4.985 5.060
V
l 3.250 3.310 3.370
V
l 3.230 3.290 3.350
V
l 1.775 1.805 1.835
V
l 1.765 1.795 1.825
V
0.001
%/V
l
2
2.4
2.8
A
l 0.9
1.2
1.5
A
l 0.17 0.24 0.31
A
0.35
Ω
0.1
1
μA
3
5
6
μA
0.8
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 LTC3637 is tested under pulsed load conditions such that
T_J ≈ T_A. The LTC3637E 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 LTC3637I is guaranteed
over the –40°C to 125°C operating junction temperature range, the
LTC3637H is guaranteed over the –40°C to 150°C operating junction
temperature range and the LTC3637MP is tested and guaranteed over the
–55°C to 150°C operating junction temperature range.
High junction temperatures degrade operating lifetimes; operating lifetime
is derated for junction temperatures greater than 125°C. 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 (P_D, in Watts) according to
the formula:
T_J = T_A + (P_D • θ_JA)
where θ_JA is 43°C/W for the DFN or 45°C/W for the MSOP.
For more information www.linear.com/LTC3637
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