LM1577, LM2577
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SNOS658D –JUNE 1999–REVISED APRIL 2013
Absolute Maximum Ratings(1)(2)
Supply Voltage
45V
65V
Output Switch Voltage
Output Switch Current(3)
6.0A
Power Dissipation
Internally Limited
−65°C to +150°C
260°C
Storage Temperature Range
Lead Temperature
Soldering, 10 sec.
Maximum Junction Temperature
Minimum ESD Rating
150°C
C = 100 pF, R = 1.5 kΩ
2 kV
(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating ratings indicate conditions the
device is intended to be functional, but device parameter specifications may not be ensured under these conditions. For ensured
specifications and test conditions, see the Electrical Characteristics.
(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and
specifications.
(3) Due to timing considerations of the LM1577/LM2577 current limit circuit, output current cannot be internally limited when the
LM1577/LM2577 is used as a step-up regulator. To prevent damage to the switch, its current must be externally limited to 6.0A.
However, output current is internally limited when the LM1577/LM2577 is used as a flyback or forward converter regulator in accordance
to the Application Hints.
Operating Ratings
Supply Voltage
3.5V ≤ VIN ≤ 40V
Output Switch Voltage
Output Switch Current
Junction Temperature Range
0V ≤ VSWITCH ≤ 60V
ISWITCH ≤ 3.0A
LM1577
LM2577
−55°C ≤ TJ ≤ +150°C
−40°C ≤ TJ ≤ +125°C
Electrical Characteristics—LM1577-12, LM2577-12
Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature
Range. Unless otherwise specified, VIN = 5V, and ISWITCH = 0.
Symbol
Parameter
Conditions
Typical
LM1577-12
Limit(1)(2)
LM2577-12
Limit(3)
Units
(Limits)
SYSTEM PARAMETERS Circuit of Figure 29(4)
VOUT
Output Voltage
VIN = 5V to 10V
12.0
V
ILOAD = 100 mA to 800 mA(1)
11.60/11.40
12.40/12.60
11.60/11.40
12.40/12.60
V(min)
V(max)
mV
Line Regulation
Load Regulation
Efficiency
VIN = 3.5V to 10V
ILOAD = 300 mA
20
20
50/100
50/100
50/100
50/100
mV(max)
(1)
(2)
VIN = 5V
ILOAD = 100 mA to 800 mA
mV
mV(max)
η
VIN = 5V, ILOAD = 800 mA
80
7.5
25
%
DEVICE PARAMETERS
IS Input Supply Current
VFEEDBACK = 14V (Switch Off)
mA
10.0/14.0
50/85
10.0/14.0
50/85
mA(max)
mA
ISWITCH = 2.0A
VCOMP = 2.0V (Max Duty Cycle)
mA(max)
(1) All limits ensured at room temperature (standard type face) and at temperature extremes (boldface type). All limits are used to calculate
Outgoing Quality Level, and are 100% production tested.
(2) A military RETS electrical test specification is available on request. At the time of printing, the LM1577K-12/883, LM1577K-15/883, and
LM1577K-ADJ/883 RETS specifications complied fully with the boldface limits in these columns. The LM1577K-12/883, LM1577K-
15/883, and LM1577K-ADJ/883 may also be procured to Standard Military Drawing specifications.
(3) All limits ensured at room temperature (standard type face) and at temperature extremes (boldface type). All room temperature limits are
100% production tested. All limits at temperature extremes are ensured via correlation using standard Statistical Quality Control (SQC)
methods.
(4) External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the
LM1577/LM2577 is used as shown in the Test Circuit, system performance will be as specified by the system parameters.
Copyright © 1999–2013, Texas Instruments Incorporated
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