Datasheet

LM5070
www.ti.com SNVS308G –OCTOBER 2004–REVISED APRIL 2013
Electrical Characteristics
(1)
(continued)
Specifications in standard type face are for T
J
= +25°C and those in boldface type apply over the full operating junction
temperature range. Unless otherwise specified: V
IN
= 48V, V
CC
= 10V, RT = 30.3kΩ.
Symbol Parameter Conditions Min Typ Max Units
ILIM Default Current Limit V
EE
= 0V, RTN = 3.0V, 325 390 420 mA
Temp = -40°C to 125°C
Current Limit Programming V
EE
= 0V, RTN = 3.0V, -20 +20 %
Accuracy RCLP = 80.6kΩ
Startup Regulator
VccReg V
CC
Regulation Open ckt 7.5 7.8 8.1 V
V
CC
Current Limit See
(2)
15 20 mA
V
CC
Supply
V
CC
UVLO (Rising) VccReg – VccReg –
300mV 100mV
V
CC
UVLO (Falling) 5.9 6.25 6.6 V
Supply Current (Icc) Cload = 0 1.5 3 mA
Error Amplifier
GBW Gain Bandwidth 4 MHz
DC Gain 75 dB
Input Voltage FB = COMP 1.219 1.281 V
1.212 1.288
COMP Sink Capability FB=1.5V COMP=1V 5 20 mA
Current Limit
ILIM Delay to Output CS step from 0 to 0.6V, 20 ns
time to onset of OUT
transition (90%)
Cycle by Cycle Current Limit 0.44 0.5 0.56 V
Threshold Voltage
Leading Edge Blanking Time 55 ns
CS Sink Impedance (clocked) 25 55 Ω
Softstart
Softstart Current Source 7 10 13 uA
Oscillator
(3)
Frequency1 175 200 225 KHz
(RT = 30.3K)
Frequency2 505 580 665 KHz
(RT = 10.5K)
Sync threshold 3.1 3.8 V
PWM Comparator
Delay to Output COMP set to 2V 25 ns
CS stepped 0 to 0.4V, time
to onset of OUT transition
low
Min Duty Cycle COMP=0V 0 %
Max Duty Cycle (-80 Device) 80 %
Max Duty Cycle (-50 Device) 50 %
COMP to PWM Comparator Gain 0.33
COMP Open Circuit Voltage 4.5 5.4 6.3 V
COMP Short Circuit Current COMP= 0V 0.6 1.1 1.5 mA
Slope Compensation
Slope Comp Amplitude Delta increase at PWM 105 mV
(LM5070-80 Device Only) Comparator to CS
(2) Device thermal limitations may limit usable range.
(3) Specification applies to the oscillator frequency. The operational frequency of the LM5070-50 devices is divided by two.
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