LINER LT1431IN8-PBF Programmable reference Datasheet

LT1431
Programmable Reference
Features
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Description
Guaranteed 0.4% Initial Voltage Tolerance
0.1Ω Typical Dynamic Output Impedance
Fast Turn-On
Sink Current Capability, 1mA to 100mA
Low Reference Pin Current
Available in J8, N8, S8 or 3-Lead TO-92 Z Packages
Applications
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Linear Regulators
Adjustable Power Supplies
Switching Power Supplies
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
The LT®1431 is an adjustable shunt voltage regulator
with 100mA sink capability, 0.4% initial reference voltage
tolerance and 0.3% typical temperature stability. On-chip
divider resistors allow the LT1431 to be configured as a
5V shunt regulator, with 1% initial voltage tolerance and
requiring no additional external components. By adding
two external resistors, the output voltage may be set to
any value between 2.5V and 36V. The nominal internal
current limit of 100mA may be decreased by including
one external resistor.
A simplified 3-pin version, the LT1431CZ/LT1431IZ, is
available for applications as an adjustable reference and
is pin compatible with the TL431.
Typical Application
Isolated 5V Regulator
+
5V
+
VIN
SWITCHING
REGULATOR
VREF vs Temperature
2.5025
2.5000
–
2.4975
RTOP
V+
COMP
VREF (V)
5V
COLL
2.4950
2.4925
REF
+
2.4900
gm =
4mA/V
2.4875
–50 –25
–
RMID
50
25
75
0
TEMPERATURE (°C)
100
125
LT1431 TA01b
2.5V
LT1431
GND-S
GND-F
LT1431 TA01
1431fd
LT1431
Absolute Maximum Ratings
(Note 1)
V+, VCOLLECTOR..........................................................36V
VCOMP, RTOP, RMID, VREF..............................................6V
GND-F to GND-S.......................................................0.7V
Ambient Temperature Range
LT1431M............................................. –55°C to 125°C
LT1431I.................................................–40°C to 85°C
LT1431C...................................................0°C TO 70°C
Junction Temperature Range
LT1431M............................................. –55°C to 150°C
LT1431I............................................... –40°C to 100°C
LT1431C.................................................. 0°C to 100°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................... 300°C
Pin Configuration
TOP VIEW
8 REF
COLLECTOR 1
3
6 GND-F
RTOP 4
5 GND-S
V
8 REF
COLLECTOR 1
7 RMID
COMP 2
+
TOP VIEW
7 RMID
COMP 2
+
3
6 GND-F
RTOP 4
5 GND-S
V
J8 PACKAGE
8-LEAD CERDIP
TJMAX = 150°C, θJA = 100°C/W
N8 PACKAGE
8-LEAD PLASTIC DIP
TJMAX = 100°C, θJA = 130°C/W
TOP VIEW
BOTTOM VIEW
COLLECTOR 1
8
REF
COMP 2
7
RMID
V+
3
6
GND-F
RTOP 4
5
GND-S
REF ANODE
CATHODE
Z PACKAGE
3-LEAD TO-92 PLASTIC
TJMAX = 100°C, θJA = 150°C/W
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 100°C, θJA = 170°C/W
Order Information
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LT1431CN8#PBF
LT1431CN8#TRPBF
LT1431 CN8
8-Lead Plastic DIP
0°C to 70°C
LT1431IN8#PBF
LT1431IN8#TRPBF
LT1431 IN8
8-Lead Plastic DIP
–40°C to 85°C
LT1431CS8#PBF
LT1431CS8#TRPBF
LT1431
8-Lead Plastic SO
0°C to 70°C
LT1431IS8#PBF
LT1431IS8#TRPBF
LT1431I
8-Lead Plastic SO
–40°C to 85°C
LT1431MJ8#PBF
LT1431MJ8#TRPBF
LT1431 MJ8
8-Lead CERDIP
–55°C to 125°C
LT1431CZ#PBF
LT1431CZ#TRPBF
LT1431 CZ
3-Lead TO-92 Plastic
0°C to 70°C
LT1431IZ#PBF
LT1431IZ#TRPBF
LT1431 IZ
3-Lead TO-92 Plastic
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Consult LTC Marketing for information on non-standard 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/
1431fd
LT1431
Electrical Characteristics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. IK = 10mA unless otherwise specified (Note 2)
LT1431I, LT1431M
SYMBOL
PARAMETER
CONDITIONS
VREF
Reference Voltage
VKA = 5V, IK = 2mA, (Note 3)
MIN
l
∆VREF/∆T
Reference Drift
TYP
MAX
LT1431C
MIN
TYP
MAX
UNITS
2.490 2.500 2.510 2.490 2.500 2.510
2.465
2.535 2.480
2.520
V
V
VKA = 5V, IK = 2mA
l
50
∆VREF/∆VKA Voltage Ratio, Reference to
Cathode (Open-Loop Gain)
IK = 2mA, VKA = 3V to 36V
l
0.2
0.5
0.2
0.5
mV/V
|IREF|
VKA = 5V, TA = 25°C
0.2
1.0
1.5
0.2
1.0
1.2
µA
µA
0.6
1.0
0.6
1.0
mA
Reference Input Current
l
IMIN
Minimum Operating Current
VKA = VREF to 36V
|IOFF|
Off-State Cathode Current
VKA = 36V, VREF = 0V
|ILEAK|
Dynamic Impedance
VKA = VREF, IK = 1mA to 100mA, f ≤ 1kHz
ILIM
Collector Current Limit
VKA = VREF + 50mV
5V Reference Output
Internal Divider Used, IK = 2mA
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: VKA is the cathode voltage of the LT1431CZ/IZ and corresponds
to V+ of the LT1431CN8/IN8/CS8/IS8. IK is the cathode current of the
ppm/°C
l
1
15
1
2
µA
µA
l
1
5
1
2
µA
µA
Off-State Collector Leakage Current VCOLL = 36V, V+ = 5V, VREF = 2.4V
|ZKA|
30
0.2
l
80
360
100
0.2
Ω
260
mA
4.950 5.000 5.050 4.950 5.000 5.050
V
LT1431CZ/IZ and corresponds to I(V+) + I
COLLECTOR of the LT1431CN8/
IN8/CS8/IS8.
Note 3: The LT1431 has bias current cancellation which is effective only
for VKA ≥ 3V. A slight (≈2mV) shift in reference voltage occurs when
VKA drops below 3V. For this reason, these tests are not performed at
VKA = VREF.
1431fd
LT1431
Typical Performance Characteristics
2.5V Reference IK vs VKA
1000
2.505
VREF and IREF vs V +
3.5
2.505
VREF and IREF vs V +
3.5
2.504
3.0
800
2.503
2.5
2.503
2.5
2.502
2.0
2.502
2.0
2.501
1.5
2.501
1.5
IMIN
IK (µA)
VREF (V)
600
500
400
2.499
300
2.498
200
100
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
VKA (V)
0
VREF
2.500
1.0
0.5
IREF
2.498
2.497
–0.5
2.497
2.496
–1.0
2.496
–1.5
2.495
2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5
+
V (V)
2.495
2.4925
–0.33
2.4900
–0.66
50
25
75
0
TEMPERATURE (°C)
–1.00
125
100
0.875
105
1
OUTPUT
LT1431
5
0.625
0.20
0.500
–50 –25
100
6
50
25
75
0
TEMPERATURE (°C)
OUTPUT HIGH-TO-LOW
30
OUTPUT LOW-TO-HIGH
15
0
50
150
100
OVERDRIVE (mV)
200
PHASE
20
LT1431 TPC07
–20
100
135
109
–45
40
–90
0
250
1010
0
60
–135
1k
10k
100k
FREQUENCY (Hz)
1M
–180
10M
LT1431 TPC08
125
180
45
80
0
–50 –25
LT1431 TPC05
90
AV
ICOLL = 20mA
ICOLL = 10mA
50
25
75
0
TEMPERATURE (°C)
100
125
LT1431 TPC06
Transconductance and Phase
vs Frequency (REF to COLL)
180
135
PHASE
108
107
90
45
gm
PHASE (DEG)
75
60
45
100
PHASE (DEG)
90
ICOLL = 50mA
0.40
120
REF-TO-COLL 1k LOAD AV (dB)
VREF ± OVERDRIVE
ICOLL = 100mA
0.60
0.750
Ω
PROPAGATION DELAY (µs)
120
1.00
0.80
140
135
0
0.7
AT 25°C
RLIM + 3.6
Voltage Gain and Phase
vs Frequency
150
–1.5
COLLECTOR VSAT vs
Temperature vs Current
1.000
LT1431 TPC04
Propagation Delay vs Overdrive
5V 1k
3
12 16 20 24 28 32 36 40
V+ (V)
8
LT1431 TPC03
VSAT (V)
0
ILIMIT (NORMALIZED)
IREF
IREF (µA)
VREF (V)
0.33
2.4875
–50 –25
4
1.20
1.125
0.66
2.4975
2.4950
0
1.250
ILIMIT =
VREF
2.5000
0
–0.5
–1.0
ILIMIT vs Temperature with
External Resistor
1.00
0.5
IREF
LT1431 TPC02
VREF and IREF vs Temperature
1.0
VREF
2.499
0
LT1431 TPC01
2.5025
2.500
REF-TO-COLL gm (µ )
700
VREF (V)
3.0
IREF (µA)
2.504
IREF (µA)
900
106
0
105
–45
104
–90
103
–135
102
100
1k
10k
100k
FREQUENCY (Hz)
1M
–180
10M
LT1431 TPC09
1431fd
LT1431
Typical Performance Characteristics
Transconductance and Phase
vs Frequency (Ref to Comp)
PHASE
gm
1.4
0
1.2
–20
103
–60
–80
3 s 102
PHASE (DEG)
–40
10k
100k
FREQUENCY (Hz)
1M
2.5
2.0
0.8
0.6
0.5
1k
10k
FREQUENCY (Hz)
LT1431 TPC10
ICOMP vs VCOMP vs VREF
LT1431 TPC11
100
125
LT1431 TPC12
0.1Hz to 10Hz Noise
NOISE VOLTAGE (50µV/DIV)
NOISE (nV/√Hz)
VREF = 5V
400
ICOMP (µA)
50
25
75
0
TEMPERATURE (°C)
1000
500
VREF = 4V
300
VREF = 3V
200
500
VREF = 2.53V
100
0
0
–50 –25
100k
Noise vs Frequency
600
ICOLL = 10mA
1.0
0
100
–140
10M
ICOLL = 100mA
1.5
0.2
–120
1k
IK ≤ 100mA
0.4
–100
0.1
100
3.0
1.0
ZKA (Ω)
Ω
REF-TO-COLL gm (µ )
3 s 103
VCOMP vs Temperature vs ICOLL
Dynamic Impedance vs Frequency
20
VCOMP (V)
104
0
0.5
1.0
1.5 2.0
VCOMP (V)
2.5
3.0
3.5
LT1431 TPC13
0
1
10
100
1k
FREQUENCY (Hz)
10k
100k
LT1431 G14
0
1
4
3
2
TIME (MINUTES)
5
6
LT1431 TPC15
1431fd
LT1431
Pin Functions
COLL (Pin 1): Open collector of the output transistor. The
maximum pin voltage is 36V. The saturation voltage at
100mA is approximately 1V.
RMID (Pin 7): Middle of the on-chip resistive divider string
between RTOP and GND-S. The pin is tied to REF for selfcontained 5V operation. It may be left open if unused.
COMP (Pin 2): Base of the driver for the output transistor. This pin allows additional compensation for complex
feedback systems and shutdown of the regulator. It must
be left open if unused.
REF (Pin 8): Control pin of the shunt regulator with a
2.5V threshold. If V+ > 3V, input bias current cancellation
reduces IB to 0.2µA typical.
V + (Pin 3): Bias voltage for the entire shunt regulator.
The maximum input voltage is 36V and the minimum to
operate is equal to VREF (2.5V). The quiescent current is
typically 0.6mA.
RTOP (Pin 4): Top of the on-chip 5k-5k resistive divider
that guarantees 1% accuracy of operation as a 5V shunt
regulator with no external trim. The pin is tied to COLL for
self-contained 5V operation. It may be left open if unused.
See note on parasitic diodes below.
GND-S (Pin 5): Ground reference for the on-chip resistive divider and shunt regulator circuitry except for the
output transistor. This pin allows external current limit
of the output transistor with one resistor between GND-F
(force) and GND-S (sense).
COMP, RTOP, RMID, and REF have static discharge protection
circuits that must not be activated on a continuous basis.
Therefore, the absolute maximum DC voltage on these pins
is 6V, well beyond the normal operating conditions.
As with all bipolar ICs, the LT1431 contains parasitic diodes
which must not be forward biased or else anomalous
behavior will result. Pin conditions to be avoided are RTOP
below RMID in voltage and any pin below GND-F in voltage
(except for GND-S).
The following pin definitions apply to the Z package.
CATHODE: Corresponds to COLL and V+ tied together.
ANODE: Corresponds to GND-S and GND-F tied together.
REF: Corresponds to REF.
GND-F (Pin 6): Emitter of the output transistor and substrate connection for the die.
Block Diagram
RTOP
V
4
+
3
COMP
2
COLLECTOR
1
5k
REF
RMID
8
+
7
–
5k
gm =
4mA/V
2.5V
5
GND-SENSE
6
LT1431 BD
GND-FORCE
1431fd
LT1431
Applications Information
Frequency Compensation
response of the LT1431 with dominant pole or pole-zero
compensation. This can be accomplished with a capacitor or
series resistor and capacitor between COLL and COMP.
As a shunt regulator, the LT1431 is stable for all capacitive
loads on the COLL pin. Capacitive loading between 0.01µF
and 18µF causes reduced phase margin with some ringing
under transient conditions. Output capacitors should not
be used arbitrarily because output noise is not necessarily
reduced.
The compensation schemes mentioned above use voltage
feedback to stabilize the circuits. There must be voltage gain
at the COLL pin for them to be effective, so the COLL pin
must see a reasonable AC impedance. Capacitive loading
of the COLL pin reduces the AC impedance, voltage gain,
and frequency response, thereby decreasing the effectiveness of the compensation schemes, but also decreasing
their necessity.
Excess capacitance on the REF pin can introduce enough
phase shift to induce oscillation when configured as a
reference >2.5V. This can be compensated with capacitance
between COLL and REF (phase lead). More complicated
feedback loops may require shaping of the frequency
Typical Applications
2.5V Reference
3-Pin Package
VIN
2.5V Reference
8-Pin Package
RL
2.5V
GND-S
ANODE
RL
5V + ∆
RTOP
GND-S
COLL
LT1431
LT1431
RMID
GND-F
GND-S
GND-F
REF
LT1431 TA04
Programmable Reference with Adjustable
Current Limit
Increasing 5V Reference
V+
RTOP
REF
COLL
LT1431 TA03
LT1431 TA02
VIN
5V
V+
COLL
LT1431
RL
VIN
2.5V
V+
REF
LT1431Z
R
RL
VIN
CATHODE
5V Reference
RL
VIN
V+
REF
COLL
LT1431
RMID
GND-F
∆ = R • (0.5mA) ±25% PROCESS TOLERANCE
∆ ≤ 500mV
R1
REF
R2
GND-F
GND-S
LT1431 TA05
( )
VOUT = 1 + R1 VREF
R2
RLIM
ILIMIT =
0.7
AT 25°C
RLIM + 3.6
LT1431 TA06
1431fd
LT1431
Typical Applications
PNP Low Dropout 5V Regulator*
VIN
0.1µF
20Ω**
2W
1k
47Ω
MJE2955
2N2219
0.015µF
150Ω
3
4
2
COMP
V+
RTOP
1
COLL
LT1431
GND-S
5
REF
RMID
8
7
GND-F
6
+
MEASURED DROPOUT VOLTAGE
420mV AT 4A
190mV AT 2A
95mV AT 1A
60mV AT 0.5A
5V
330µF
LT1431 TA07
*NO SHORT-CIRCUIT PROTECTION
**MAY BE INCREASED AT LOWER WATTAGE
FOR LOWER OUTPUT CURRENTS
FET Low Dropout 5V Regulator with Current Limit
12V
VIN ≥ 5.2V
MTP50N05EL
MTM25N05L
+
D
47µF
0.002Ω*
S
–
G
1.5k
7
2
+
3
+
4
5V, 2.5A
47µF
LT1006
LT1006
5
1N4148
Measured Dropout Voltages
ILOAD
2A
1A
0.5A
MTP50N05EL
47mV
22mV
11.5mV
MTM25N05L
145mV
73mV
37mV
3
4
1
COLL
V+
RTOP
GND-S
5
LT1431
REF
RMID
6
8
7
GND-F
6
LT1431 • TA08
*1.5" #23 SOLID COPPER WIRE
~0.002Ω m 3A LIMIT
1431fd
LT1431
Typical Applications
12V to 5V Buck Converter with Foldback Current Limit*
Buck Converter Efficiency
80
PULSE ENGINEERING
#PE-51515
VOUT
LT1089
HI-SIDE SWITCH
LOGIC IN
3
4
100Ω
0.5W
MBR735
GND
5k
1500pF
2
COMP
V+
RTOP
GND-S
5
VIN = 12V
60
VIN = 15V
50
40
1
COLL
LT1431
VIN = 9V
70
EFFICIENCY (%)
VIN
VIN
REF
RMID
8
30
7
0
1
2
4
3
5
6
ILOAD (A)
GND-F
6
+
*CONTACT LTC FOR HIGH EFFICIENCY
SWITCHING REGULATORS
7
8
LT1431 TA10
5V, 7A
3300µF
LT1431 TA09
Isolated 5V to ± 15V Flyback Converter
COILTRONICS
CTX02-11934
6, 7
4.5V
TO 5.5V
0.47µF
VIN
LT1172
OR
LT1072
GND
VOUT
C*
210µF
LT1172
LT1072
30mVP-P
40mVP-P
6mVP-P
8mVP-P
15k
L*
•
+
2
10
100µF
+
100µF
*L BELL INDUSTRIES J.W. MILLER
DIVISION 9310-36 10µH, 450mA
•
VC
+
15V, 70mA
C*
1.5k
4N36
0.68µF
LT1431 TA12
MUR105
1
MEASURED EFFICIENCY
LT1172 67.8% AT 2.2WOUT
LT1072 68.6% AT 2.2WOUT
LT1071 61.1% AT 4.4WOUT
+
–15V, 70mA
+
•
4, 5
50µF
C*
MUR105
3k
MUR105
+
9
Fully Loaded Output Ripple vs Filtering
2.4k
0.1µF
1
20k 2
3
V+
8
REF
COLL
LT1431
COMP
GND-S
5
13.3k
2.7k
GND-F
6
LT1431 TA11
1431fd
LT1431
Typical Applications
5V Power Supply Monitor with ± 500mV
Window and 50mV Hysteresis
Transfer Function
6
1k
6k*
1k
4k*
V+
V+
COLL
REF
LT1431
GND-S
4
VOUT
1N4148
5
“HIGH” FOR
OVER VOLTAGE OR
UNDER VOLTAGE
COLL
REF
LT1431
5k
GND-F
GND-S
2
5k
GND-F
1
10Ω** *DETERMINES WINDOW SIZE
V = (R – 5k)(0.5mA)
**SETS HYSTERESIS
10Ω**
3
0
0
1
2
LT1431 TA13
3
VIN
4
5
6
LT1431 TA14
High Efficiency Buck Converter E = 85% to 89%
1
+
D1
BAT85
C1
220µF
35V
BOLD LINES INDICATE HIGH CURRENT PATHS
*1% FILM RESISTORS
C1: NICHICON UPL1V221MPH
C3, C4, C5: WIMA MKS-2
C6: NICHICON UPL1C471MPH6
D1, D2: PHILIPS BAT85
D3: MOTOROLA MBR330
L1: COILTRONICS CTX50-3-MP
5
VIN
4
VSW
LT1170
2
FB
GND
VC
R1
470k
+
C2
4.7µF
35V
TANT
3
D4
BAT85
C5
0.047µF
1
R2
1k
C3
0.1µF
C4
0.033µF
D3
L1
MBR330 50µH 3A
0.12Ω
ESR
D2
BAT85
OFF
1
RUN = 0
SHUTDOWN > 3V
R3
10k
RTN
R4
100Ω
2
5V
2.5A
1
COMP
Q3
2N3904
R5
680Ω
C6
470µF
16V
R6*
23.7k
Q2
2N3904
Q1
VN2222LL
+
VIN
R8*
24.9k
COLL
3 +
8
V
REF
LT1431CN8
4
7
RTOP
RMID
GND-S
GND-F
5
6
R7*
24.9k
2
NOTES: UNLESS OTHERWISE SPECIFIED
1. ALL RESISTANCES ARE IN Ω, 0.25W, 5%
2. ALL CAPACITANCES ARE IN µF, 50V, 10%
3. SHUTDOWN LOGIC STATE MUST BE DEFINED BY A LOGIC GATE OR BY TYING TO GND
1431 TA15
1431fd
10
LT1431
Schematic Diagram
Q5
R1
35k
4X
R2
35k
Q2
Q1
Q7
3
Q13
V
+
Q17
3X
Q10
Q11
Q3
Q12
Q6
2X
8
REF
Q9
Q14
C1
22pF
R11
11k
C2
65pF
R15
5k
R17
1.5k
R13
6.5k
COLLECTOR
1
Q20
2X
C4
1pF
Q22
45X
Q18 Q19
R9
2.5k
Q8
7
Q15
R5
5k
R8
600Ω
5
R10
340Ω
R20
5k
R16
11Ω
Q16
10X
R4
5k
GND-SENSE
C3
6pF
R7
2.5k
4
R3
5k
R MID
R12
1k
5X
R6
8.5k
Q4
RTOP
COMP
2
Q21
2.5X
R14
11Ω
R21
100k
R18
50k
R19
3.6Ω
6
GND-FORCE
LT1431 SD01
Package Description
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
.300 BSC
(7.62 BSC)
.008 – .018
(0.203 – 0.457)
.200
(5.080)
MAX
CORNER LEADS OPTION
(4 PLCS)
0° – 15°
.015 – .060
(0.381 – 1.524)
.023 – .045
(0.584 – 1.143)
HALF LEAD
OPTION
.045 – .068
(1.143 – 1.650)
FULL LEAD
OPTION
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
.005
(0.127)
MIN
.405
(10.287)
MAX
8
.014 – .026
(0.360 – 0.660)
.100
(2.54)
BSC
6
5
.025
(0.635)
RAD TYP
.220 – .310
(5.588 – 7.874)
1
.045 – .065
(1.143 – 1.651)
7
2
3
4
J8 0801
.125
3.175
MIN
1431fd
11
LT1431
Package Description
N8 Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
.300 – .325
(7.620 – 8.255)
(
+.035
.325 –.015
8.255
+0.889
–0.381
.130 ± .005
(3.302 ± 0.127)
.045 – .065
(1.143 – 1.651)
.065
(1.651)
TYP
.008 – .015
(0.203 – 0.381)
.400*
(10.160)
MAX
8
7
6
5
1
2
3
4
.255 ± .015*
(6.477 ± 0.381)
)
.120
(3.048) .020
MIN (0.508)
MIN
.018 ± .003
.100
(2.54)
BSC
N8 1002
(0.457 ± 0.076)
NOTE:
1. DIMENSIONS ARE
INCHES
MILLIMETERS
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.050 BSC
.189 – .197
(4.801 – 5.004)
NOTE 3
.045 ±.005
8
.245
MIN
.160 ±.005
.010 – .020
× 45°
(0.254 – 0.508)
NOTE:
1. DIMENSIONS IN
5
.150 – .157
(3.810 – 3.988)
NOTE 3
1
RECOMMENDED SOLDER PAD LAYOUT
.053 – .069
(1.346 – 1.752)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
6
.228 – .244
(5.791 – 6.197)
.030 ±.005
TYP
.008 – .010
(0.203 – 0.254)
7
.014 – .019
(0.355 – 0.483)
TYP
INCHES
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
2
3
4
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
SO8 0303
1431fd
12
LT1431
Revision History
(Revision history begins at Rev D)
REV
DATE
DESCRIPTION
PAGE NUMBER
D
4/10
M-Grade Parts Re-Released. Obsolete Package Shading Removed
2, 11
1431fd
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
13
LT1431
Package Description
Z Package
3-Lead Plastic TO-92 (Similar to TO-226)
(Reference LTC DWG # 05-08-1410 Rev C)
.180 p .005
(4.572 p 0.127)
.060 p .005
(1.524p 0.127)
DIA
.90
(2.286)
NOM
.180 p .005
(4.572 p 0.127)
.500
(12.70)
MIN
.050 UNCONTROLLED
(1.270) LEAD DIMENSION
MAX
.016 p .003
(0.406 p 0.076)
.050
(1.27)
BSC
5o
NOM
.015 p .002
(0.381 p 0.051)
BULK PACK
TO-92 TAPE AND REEL
REFER TO TAPE AND REEL SECTION OF
LTC DATA BOOK FOR ADDITIONAL INFORMATION
.060 p .010
(1.524 p 0.254)
3
2
Z3 (TO-92) 1008 REV C
.098 +.016/–.04
(2.5 +0.4/–0.1)
2 PLCS
.140 p .010
(3.556 p 0.127)
1
10o NOM
Related Parts
PART NUMBER
DESCRIPTION
COMMENTS
LTC 3722
Synchronous Full-Bridge Controller
Zero Voltage Switching, Adjustable 2VS Timing
LTC3723
Synchronous Push-Pull PWM Controller
1.5A Sink, 1A Source Output Drivers, Adjustable Dead Time
LTC3803
SOT-23 Flyback Controller
Adjustable Slope Compensation, 200kHz Operation
LTC3806
Synchronous Flyback Controller
Excellent Cross Regulation, High Efficiency
®
LTC3900/LTC3901 Synchronous Rectifiers for Forward and Push-Pull Converters Programmable Time Out, Reverse Inductor Current Sense
LT4430
Opto-Coupler Driver in SOT-23
Overshoot Control, 600mV Reference, High Bandwidth Error Amplifier
1431fd
14 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
LT 0410 REV D • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 1992
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