Datasheet

LM5046
SNVS703G –FEBRUARY 2011–REVISED MARCH 2013 www.ti.com
Electrical Characteristics (continued)
Limits in standard typeface are for T
J
= 25°C only; limits in boldface type apply the junction temperature range of -40°C to
+125°C. Unless otherwise specified, the following conditions apply: VIN = 48V, RT = 25kΩ, RD1=RD2=20kΩ. No load on
HO1, HO2, LO1, LO2, SR1, SR2, COMP=0V, UVLO=2.5V, OVP=0V, SSOFF=0V.
Symbol Parameter Conditions Min Typ Max Units
Soft-Stop Disable (SS OFF Pin)
V
IH(min)
SSOFF Input Threshold 2.8 V
SSOFF pull down resistance 200 kΩ
Current Limit Restart (RES Pin)
R
RES
RES pull-down resistance Termination of hiccup timer 37 Ω
V
RES
RES hiccup threshold 1 V
RES upper counter threshold 4 V
RES lower counter threshold 2 V
I
RES-SRC1
Charge current source 1 V
RES
<1V,V
CS
>750mV 30 µA
I
RES-SRC2
Charge current source 2 1V<V
RES
<4V 10 µA
I
RES-DIS2
Discharge current source 1 V
CS
<750mV 5 µA
I
RES-DIS2
Discharge current source 2 2V<V
RES
<4V 5 µA
Ratio of time in hiccup mode to time V
RES
>1V, Hiccup counter 147
in current limit
Voltage Feed-Forward (RAMP Pin)
RAMP sink impedance (Clocked) 5.5 20 Ω
Oscillator (RT Pin)
F
SW1
Frequency (LO1, half oscillator R
T
= 25 kΩ 185 200 215 kHz
frequency)
F
SW2
Frequency (LO1, half oscillator R
T
= 10 kΩ 420 480 540 kHz
frequency)
DC level 2.0 V
RT sync threshold 2.8 3 3.3 V
ZVS Timing Control (RD1 & RD2 Pins)
T
PA
HO1/SR1 turn-off to LO1 turn-on R
D1
=20 kΩ 39 65 89 ns
LO1/SR2 turn-off to HO1 turn-on
R
D1
=100 kΩ 230 300 391 ns
T
AP
LO2 turn-off to HO2 turn-on R
D2
=20 kΩ 27 55 78 ns
HO2 turn-off to LO2 turn-on
R
D2
=100 kΩ 214 300 378 ns
Comp Pin
V
PWM-OS
COMP current to RAMP offset V
RAMP
=0V 680 800 940 µA
V
SS-OS
SS to RAMP offset V
RAMP
=0V 0.78 1.0 1.22 V
COMP current to RAMP gain ΔRAMP/ΔI
COMP
2400 Ω
SS to RAMP gain ΔSS/ΔRAMP 0.5
COMP current for SSSR charge V
SS
> 2V 690 800 915 µA
current enable
COMP to output delay 120 ns
Minimum duty cycle I
COMP
= 1mA 0 %
Slope Compensation (SLOPE Pin)
I
SLOPE
Slope compensation current ramp Peak of RAMP current 100 µA
BOOST (BST Pin)
V
Bst uv
BST under-voltage threshold V
BST
-V
HS
rising 3.8 4.7 5.6 V
Hysteresis 0.5 V
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