Datasheet

LM25576, LM25576-Q1
SNVS470G –JANUARY 2007–REVISED APRIL 2013 www.ti.com
Electrical Characteristics
Specifications with standard typeface are for T
J
= 25°C, and those with boldface type apply over full Operating Junction
Temperature range. V
IN
= 24V, R
T
= 32.4kΩ unless otherwise stated.
(1)
Symbol Parameter Conditions Min Typ Max Units
STARTUP REGULATOR
VccReg Vcc Regulator Output 6.85 7.15 7.45 V
Vcc LDO Mode turn-off 9 V
Vcc Current Limit Vcc = 0V 25 mA
VCC SUPPLY
Vcc UVLO Threshold (Vcc increasing) 5.03 5.35 5.67 V
Vcc Undervoltage Hysteresis 0.25 V
Bias Current (Iin) FB = 1.3V 3.4 4.5 mA
Shutdown Current (Iin) SD = 0V 48 70 µA
SHUTDOWN THRESHOLDS
Shutdown Threshold (SD Increasing) 0.47 0.7 0.9 V
Shutdown Hysteresis 0.1 V
Standby Threshold (Standby Increasing) 1.17 1.225 1.28 V
Standby Hysteresis 0.1 V
SD Pull-up Current Source 5 µA
SWITCH CHARACTERSICS
Buck Switch Rds(on) 170 340 mΩ
BOOST UVLO 3.8 V
BOOST UVLO Hysteresis 0.56 V
Pre-charge Switch Rds(on) 70 Ω
Pre-charge Switch on-time 265 ns
CURRENT LIMIT
Cycle by Cycle Current Limit RAMP = 0V 3.6 4.2 5.1 A
Cycle by Cycle Current Limit Delay RAMP = 2.5V 100 ns
SOFT-START
SS Current Source 7 10 14 µA
OSCILLATOR
Frequency1 180 200 220 kHz
Frequency2 R
T
= 11kΩ 425 485 545 kHz
SYNC Source Impedance 11 kΩ
SYNC Sink Impedance 110 Ω
SYNC Threshold (falling) 1.3 V
SYNC Frequency R
T
= 11kΩ 550 kHz
SYNC Pulse Width Minimum 15 ns
RAMP GENERATOR
Ramp Current 1 Vin = 36V, Vout=10V 136 160 184 µA
Ramp Current 2 Vin = 10V, Vout=10V 18 25 32 µA
PWM COMPARATOR
Forced Off-time 416 500 575 ns
Min On-time 80 ns
COMP to PWM Comparator Offset 0.7 V
ERROR AMPLIFIER
Feedback Voltage Vfb = COMP 1.207 1.225 1.243 V
(1) Min and Max limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through correlation
using Statistical Quality Control (SQC) methods. Limits are used to calculate Texas Instruments' Average Outgoing Quality Level
(AOQL).
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