Datasheet

LM25088
LM25088-Q1
SNVS609H –DECEMBER 2008–REVISED MARCH 2013 www.ti.com
Electrical Characteristics
Limits in standard type are for T
J
= 25°C only; limits in boldface type apply over the junction temperature (T
J
) range of -40°C
to +125°C. Minimum and Maximum limits are specified through test, design, or statistical correlation. Typical values represent
at T
J
= 25°C, and are provided for reference purposes only. Unless otherwise stated the following conditions apply: V
VIN
=
24V, V
VCC
= 8V, V
EN
= 5V R
RT
= 31.6 kΩ, No load on HG. See note
(1)
.
Symbol Parameter Conditions Min Typ
(1)
Max Units
VIN SUPPLY
I
BIAS
VIN Operating Current V
FB
= 1.3V 3.2 4.5 mA
I
STANDBY
VIN Standby Current V
EN
= 1V 2.5 3.0 mA
I
SHUTDOWN
VIN Shutdown Current V
EN
= 0V 14 24 µA
VCC REGULATOR
V
VCC(Reg)
VCC Regulation V
VCC
= open 7.4 7.8 8.2 V
V
VCC(Reg)
VCC Regulation V
VIN
= 4.5V,VVCC=open 4.3 4.5 V
VCC Sourcing Current Limit V
VCC
= 0 25 30 mA
V
VCC(UV)
VCC Under-Voltage Lockout Threshold Positive going VVCC 3.7 4 4.2 V
VCC Under-Voltage Hysteresis 200 mV
ENABLE THRESHOLDS
EN Shutdown Threshold V
EN
Rising 320 400 480 mV
EN Shutdown Hysteresis V
EN
Falling 100 mV
EN Standby Threshold V
EN
Rising 1.1 1.2 1.3 V
EN Standby Hysteresis V
EN
Falling 120 mV
EN Pull-up Current Source V
EN
= 0V 5 µA
SOFT- START
SS Pull-up Current Source V
SS
= 0V 8 11 13 µA
FB to SS Offset V
FB
= 1.3V 150 mV
ERROR AMPLIFIER
V
REF
FB Reference Voltage Measured at FB Pin 1.187 1.205 1.223 V
FB = COMP
FB Input Bias Current V
FB
= 1.2V 18 100 nA
COMP Sink/Source Current 3 mA
AOL DC Gain 60 dB
FBW Unity gain bandwidth 3 MHz
PWM COMPARATORS
T
HG(OFF)
Forced HG Off-time 185 280 365 ns
T
ON(MIN)
Minimum HG On-time V
VIN
= 36V 55 ns
COMP to PWM comparator offset 930 mV
OSCILLATOR (RT Pin)
LM25088-2 (Non-Dithering)
F
nom1
Nominal Oscillator Frequency R
RT
=31.6 kΩ 180 200 220 kHz
F
nom2
R
RT
= 11.3 kΩ 430 500 565 kHz
LM25088-1 (Dithering)
F
min
Dithering Range Minimum Dither Frequency F
nom
-5% kHz
F
max
Maximum Dither Frequency F
nom
+5% kHz
SYNC
SYNC positive threshold 2.3 V
SYNC Pulse Width 15 150 ns
CURRENT LIMIT
V
CS(TH)
Cycle by cycle sense voltage threshold V
RAMP
= 0V 112 120 136 mV
Cycle by Cycle Current Limit Delay V
RAMP
= 2.5V 280 ns
(1) Typical specifications represent the most likely parametric norm at 25°C operation.
4 Submit Documentation Feedback Copyright © 2008–2013, Texas Instruments Incorporated
Product Folder Links: LM25088 LM25088-Q1