Datasheet

LM3495
SNVS410F –FEBRUARY 2006–REVISED APRIL 2013 www.ti.com
Electrical Characteristics
Specifications with standard type are for T
J
= 25°C only; limits in boldface type apply over the full Operating Junction
Temperature (T
J
) range. Minimum and Maximum limits are specified through test, design, or statistical correlation. Typical
values represent the most likely parametric norm at T
J
= 25°C, and are provided for reference purposes only. Unless
otherwise indicated, V
IN
= 12V.
Symbol Parameter Conditions Min Typ
(1)
Max Units
SYSTEM PARAMETERS
-20°C to 85°C 0.594 0.6 0.606
V
FB
FB Pin Voltage V
-40°C to 125°C 0.591 0.6 0.609
Line Regulation 2.9V < VIN < 18V, COMP/SD = 1.5V 0.1 %
ΔV
FB
/V
FB
Load Regulation 1.1V < COMP/SD <1.8V 0.1 %
VIN Rising 2.55 2.6 2.7
V
ON
UVLO Thresholds V
VIN Falling 2.26 2.3 2.45
Operating VIN Current COMP/SD > 0.3V, Not switching 1.8 mA
I
Q
Quiescent Current COMP/SD < 0.3V, Shutdown, VIN = 18V 33 µA
I
ILIM
ILIM Pin Source Current 18 20 22 µA
V
ILIM-MAX
Maximum Current Limit Sense Voltage 200 mV
I
SD
COMP/SD Pin Pull-up current COMP/SD = 0V 2 2.6 µA
V
HICCUP
COMP/SD Pin Hiccup Threshold 2 V
t
DELAY
Hiccup Delay 16 Cycles
t
COOL
Cool Down Time Until Restart 4096 Cycles
t
SS
Internal Soft start Time 400 Cycles
V
OVP
Over Voltage Protection Threshold As a % of nominal output voltage 116 125 132 %
I
FPWM
FPWM Pin Pull-up Current FPWM = 0V 4.5 µA
V
FPWM-LO
FPWM Operation Threshold FPWM Voltage Falling 0.9 V
R
SNS
SNS Pin Input Resistance SNS = 1.5V, COMP/SD > 0.3V 30 kΩ
R
DIS
SNS Pin Discharge FET R
DSON
SNS = 1.5V, COMP/SD = 0V 350 440 530 Ω
GATE DRIVE
I
BOOST
BOOST Pin Leakage Current BOOST - SW = 5.5V 25 nA
High-Side FET Driver Pull-up ON
R
DS1
BOOST - SW = 4.5V 4.5 Ω
resistance
High-Side FET Driver Pull-down ON
R
DS2
BOOST - SW = 4.5V 0.9 Ω
resistance
Low-Side FET Driver Pull-up ON
R
DS3
VLIN5 = 5.5V 1.4 Ω
resistance
Low-Side FET Driver Pull-down ON
R
DS4
VLIN5 = 5.5V 0.7 Ω
resistance
OSCILLATOR
R
ADJ
= 150 kΩ 200
f
SW
PWM Frequency R
ADJ
= 54.9 kΩ 450 500 550 kHz
R
ADJ
= 17.8 kΩ 1500
V
SYNC-HI
Threshold for SYNC on FREQ Pin SYNC Voltage Rising 1.2 V
V
SYNC-LO
Threshold for SYNC on FREQ Pin SYNC Voltage Falling 0.3 V
t
ON-SKIP
On Time During Skip Mode V
O
= 1.5V, f
SW
= 500 kHz 125 ns
t
ON-MAX
Adaptive Maximum On-time Limit V
O
= 1.5V, f
SW
= 500 kHz 750 ns
t
OFF-MIN
Minimum Off-time 300 ns
ERROR AMP
g
M
Transconductance 750 µmho
BW
-3dB
Open Loop Bandwidth COMP/SD Floating 5 MHz
I
FB
FB Pin Bias Current V
FB
= 0.6V 1 nA
(1) Typical specifications represent the most likely parametric norm at 25°C operation.
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