Operating Temperature Range (Note 2) ....–40°C to 125°C
Storage Temperature Range .................. –65°C to 150°C
MS PACKAGE
16-LEAD PLASTIC MSOP
θ
JA
= 125°C/W
orDer inForMaTion
LEAD FREE FINISH
LT8312EMS#PBF
LT8312IMS#PBF
LT8312HMS#PBF
LT8312MPMS#PBF
TAPE AND REEL
LT8312EMS#TRPBF
LT8312IMS#TRPBF
LT8312HMS#TRPBF
(http://www.linear.com/product/LT8312#orderinfo)
PART MARKING*
8312
8312
8312
8312
PACKAGE DESCRIPTION
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
16-Lead Plastic MSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–55°C to 150°C
LT8312MPMS#TRPBF
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
2
8312fa
For more information
www.linear.com/LT8312
LT8312
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C.
PARAMETER
Input Voltage Range
Quiescent Current
V
IN
Quiescent Current, INTV
CC
Overdriven
V
IN
Shunt Regulator Voltage
V
IN
Shunt Regulator Current Limit
INTV
CC
Quiescent Current
EN/UVLO Pin Threshold
EN/UVLO Pin Hysteresis Current
V
REF
Voltage
SENSE Current Limit Threshold
Minimum SENSE Current Limit
SENSE Input Bias Current
Current Sense Blanking Time
FB Voltage
FB Voltage Line Regulation
FB Pin Bias Current
FB Error Amplifier Voltage Gain
FB Error Amplifier Transconductance
FB Low Detection Voltage
DCM Current Turn-On Threshold
Maximum Oscillator Frequency
Linear Regulator
INTV
CC
Regulation Voltage
Dropout (V
IN
-INTV
CC
)
Current Limit
Gate Driver
t
r
GATE Driver Output Rise Time
t
f
GATE Driver Output Fall Time
GATE Output Low (V
OL
)
GATE Output High (V
OH
)
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2:
The LT8312E is guaranteed to meet specified performance from
0°C to 125°C junction temperature. Specification over the –40°C and
125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT8312I is guaranteed to meet specified performance from –40°C to
INTV
CC
–
50mV
125°C operating junction temperature range. The LT8312H is guaranteed
to meet performance specifications over the –40°C to 150°C operating
junction temperature range. The LT8312MP is guaranteed to meet
performance specifications over the –55°C to 150°C operating junction
temperature range. High junction temperatures degrade operating
lifetimes. Operating lifetime is derated for junction temperatures greater
than 125°C.
Note 3:
Current flows out of the FB pin.
C
L
= 3300pF
C
L
= 3300pF
18
18
0.01
ns
ns
V
V
I
INTVCC
= –10mA, V
IN
= 10V
INTV
CC
< 9.5V
INTV
CC
> 9.5V
12
80
9.8
10
500
25
120
10.4
900
V
mV
mA
mA
Current Out of Pin
10V < V
IN
< 35V
(Note 3), FB = 1.25V, OVP = 1.35V
ΔV
VC
/ΔV
FB
ΔI = 5µA
l
elecTrical characTerisTics
CONDITIONS
V
EN/UVLO
= 0.2V
Not Switching
V
INTVCC
= 11V
I = 1mA
V
EN/UVLO
= 0.2V
V
EN/UVLO
= 1.5V, Not Switching
EN/UVLO Pin Voltage Rising
EN/UVLO = 1V
0µA Load
200µA Load
l
l
l
MIN
10
45
TYP
60
70
60
40
8
MAX
38
70
UNITS
V
µA
µA
µA
V
mA
12.5
1.8
1.21
8
1.97
1.95
96
15.5
2.2
1.25
10
2.0
1.98
102
3
15
17.5
2.7
1.29
12
2.03
2.03
107
µA
mA
V
μA
V
V
mV
mV
µA
Current Out of Pin
90
1.22
130
1.25
0.01
100
180
170
0.1
80
400
170
1.28
0.03
600
ns
V
%/V
nA
V/V
µmhos
V
µA
kHz
8312fa
For more information
www.linear.com/LT8312
3
LT8312
Typical perForMance characTerisTics
EN/UVLO Threshold
vs Temperature
1.3
EN/UVLO HYSTERESIS CURRENT (µA)
12
Input Voltage Hysteresis Current
vs Temperature
100
90
11.5
80
70
I
Q
(µA)
60
50
40
30
20
10
10
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
8312 G02
V
IN
I
Q
vs Temperature
V
IN
= 24V
V
IN
= 12V
1.28
RISING
EN/UVLO (V)
1.26
11
1.24
FALLING
1.22
10.5
1.2
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
8312 G01
0
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
8312 G03
2.100
2.075
2.050
V
REF
vs Temperature
2.05
2.04
V
REF
vs V
IN
SENSE Pin Threshold Current
vs Temperature
120
100
80
60
40
20
0
–50 –25
MAX I
LIM
2.02
V
REF
(V)
V
IN
= 24V WITH NO LOAD
2.01
2
1.99
1.98
1.97
1.96
0
25 50 75 100 125 150
TEMPERATURE (°C)
8312 G04
2.025
V
REF
(V)
2.000
1.975
1.950
1.925
1.900
–50 –25
NO LOAD
V
IN
= 24V WITH 200µA LOAD
200µA LOAD
1.95
10
15
20
25
V
IN
(V)
30
35
40
8312 G05
SENSE CURRENT LIMIT (mV)
2.03
0
25 50 75 100 125 150
TEMPERATURE (°C)
8312 G06
10.5
INTV
CC
vs Temperature
NO LOAD
10mA LOAD
25mA LOAD
10.2
10
9.8
INTV
CC
vs V
IN
42
41.5
V
IN
SHUNT VOLTAGE (V)
41
V
IN
Shunt Voltage vs Temperature
I
SHUNT
= 1mA
10.25
INTV
CC
(V)
10
INTV
CC
(V)
9.6
9.4
9.2
40.5
40
9.75
39.5
39
–50 –25
9.5
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
8312 G07
9
5
10
15
25
20
V
IN
(V)
30
35
40
8312 G08
0
25 50 75 100 125 150
TEMPERATURE (°C)
8312 G09
4
8312fa
For more information
www.linear.com/LT8312
LT8312
Typical perForMance characTerisTics
Maximum V
IN
Shunt Current
vs Temperature
10
60
50
POWER FACTOR
40
8
THD
30
20
10
0
230VAC 50Hz
THD vs Output Power
1.00
0.95
0.90
0.85
0.80
0.75
0.70
115VAC
0
20
40
60 80 100 120 140 160
POWER (W)
8312 G11
Power Factor vs Output Power
115VAC
9
SHUNT CURRENT (mA)
230VAC 50Hz
7
6
0.65
0.60
0
20
40
60 80 100 120 140 160
POWER (W)
8312 G12
5
–50 –25
0
25 50 75 100 125 150
TEMPERATURE (°C)
8312 G10
pin FuncTions
GND (Pins 1, 2, 3, 7, 8):
Ground.
V
REF
(Pin 4):
Voltage Reference Output Pin, Typically
2V. This pin drives a resistor divider for the OVP pin. Can
supply up to 200μA.
OVP (Pin 5):
Overvoltage Protection. This pin accepts a
DC voltage to compare to the voltage output information.
When FB pin voltage is above the OVP, the part stops
switching. This protects devices connected to the output.
V
C
(Pin 6):
Compensation Pin for Internal Error Amplifier.
Connect a series RC from this pin to ground to compen-
sate the switching regulator. A 100pF capacitor in parallel
helps eliminate noise.
FB (Pin 9):
Voltage Loop Feedback Pin. FB is used to
regulate the output voltage.
DCM (Pin 10):
Discontinuous Conduction Mode Detection
Pin. Connect a capacitor and resistor in series with this
pin to the auxiliary winding.
V
IN
(Pin 11):
Input Voltage. This pin supplies current to
the internal start-up circuitry and to the INTV
CC
LDO. This
pin must be locally bypassed with a capacitor. A 42V shunt
regulator is internally connected to this pin.
EN/UVLO (Pin 12):
Enable/Undervoltage Lockout. A resis-
tor divider connected to V
IN
is tied to this pin to program
the minimum input voltage at which the LT8312 will turn
on. When below 1.25V, the part will draw 60μA with most
of the internal circuitry disabled and a 10μA hysteresis
current will be pulled out of the EN/UVLO pin. When above
1.25V, the part will be enabled and begin to switch and
the 10μA hysteresis current is turned off.
INTV
CC
(Pin 13):
Regulated Supply for Internal Loads
and GATE Driver. Supplied from V
IN
and regulates to 10V
(typical). INTV
CC
must be bypassed with a 4.7μF capacitor
placed close to the pin.
GATE (Pin 14):
N-Channel FET Gate Driver Output. Switches
between INTV
CC
and GND. Driven to GND during shutdown
state and stays high during low voltage states.
SENSE (Pin 15):
The Current Sense Input for the Control
Loop. Kelvin connect this pin to the positive terminal of the
switch current sense resistor, R
SENSE
, in the source of the
NFET. The negative terminal of the current sense resistor
should be connected to the GND plane close to the IC.
V
IN(SENSE)
(Pin 16):
Line Voltage Sense Pin. The pin is
used for sensing the AC line voltage to perform power
factor correction. Connect a resistor in series with the
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
