LT1178SW#TRPBF [Linear]
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| 型号： | LT1178SW#TRPBF |
| 厂家： | 
Linear |
| 描述： | 暂无描述 比较器 |
| 文件： | 总12页 (文件大小：147K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LTC1540
Nanopower Comparator
with Reference
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FEATURES
DESCRIPTIO
The LTC®1540 is an ultralow power, single comparator
with built-in reference. The comparator’s features
include less than 0.6µA supply current over the commer-
cial temperature range, a 1.182V ±2% reference, pro-
grammable hysteresis and TTL/CMOS outputs that sink
and source current. The reference output can drive a
bypass capacitor of up to 0.01µF without oscillation.
■
Ultralow Quiescent Current: 0.3
Reference Output Drives 0.01
Adjustable Hysteresis
Available in 3mm x 3mm x 0.8mm DFN Package
Wide Supply Range: 2V to 11V
Input Voltage Range Includes the Negative Supply
Reference Output Sources Up to 1mA
TTL/CMOS Compatible Outputs
60µs Propagation Delay with 10mV Overdrive
No Crowbar Current
40mA Continuous Source Current
Pin Compatible with LTC1440, MAX921, MAX931
µ
A Typ
■
µF Capacitor
■
■
■
■
■
■
■
■
■
■
The comparator operates from a single 2V to 11V supply
or a dual ±1V to ±5.5V supply. Comparator hysteresis is
easily programmed by using two resistors and the HYST
pin. Each comparator’s input operates from the negative
supply to within 1.3V of the positive supply. The compara-
tor output stage can continuously source up to 40mA. By
eliminating the cross-conducting current that normally
occur when the comparator changes logic states, power
supply glitches are eliminated.
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APPLICATIO S
■
Battery-Powered System Monitoring
■
Threshold Detectors
■
Window Comparators
Oscillator Circuits
The LTC1540 is available in the 8-pin MSOP and SO
packages. For space limited applications, the LTC1540 is
available in a 3mm x 3mm low profile (0.8mm) dual fine-
pitch leadless package (DFN).
■
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIO
Nanopower 2.9V VCC Threshold Detector
LTC1540 Supply Current vs Temperature
3.3V
0.50
+
7
R1
4.32M
1%
V
V
= 5V
–
+
= GND = 0V
0.45
0.40
0.35
0.30
0.25
0.20
0.15
V
LTC1540
+
–
3
4
5
6
IN
+
–
8
R2
3M
1%
OUT
IN
HYST
REF
–
40
0
TEMPERATURE (°C)
80 100
–40 –20
20
60
GND
V
2
1
1540 • TA02
1540
• TA01
sn1540 1540fas
1
LTC1540
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ABSOLUTE MAXIMUM RATINGS
OUT Short-Circuit Duration (V+ ≤ 5.5V) ...... Continuous
Power Dissipation............................................. 500mW
Operating Temperature Range
LTC1540C .............................................. 0°C to 70°C
LTC1540I............................................ –40°C to 85°C
Storage Temperature Range ................ –65°C to 150°C
(DD Package) ................................... –65°C to 125°C
Lead Temperature (Soldering, 10 sec).................. 300°C
Voltage
V+ to V–, V+ to GND, GND to V– ...........12V to –0.3V
IN+, IN–, HYST ................. (V+ + 0.3V) to (V– – 0.3V)
REF................................... (V+ + 0.3V) to (V– – 0.3V)
OUT ............................... (V+ + 0.3V) to (GND – 0.3V)
Current
IN+, IN–, HYST ................................................. 20mA
REF................................................................... 20mA
OUT .................................................................. 50mA
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PACKAGE/ORDER INFORMATION
TOP VIEW
TOP VIEW
TOP VIEW
GND
1
2
3
4
8
7
6
5
OUT
GND
1
2
3
4
8
7
6
5
OUT
GND
1
2
3
4
8 OUT
7 V
6 REF
5 HYST
–
+
–
+
–
+
V
IN
V
V
V
V
+
–
+
+
IN
REF
IN
REF
IN
–
–
IN
HYST
IN
HYST
MS8 PACKAGE
8-LEAD PLASTIC MSOP
S8 PACKAGE
8-LEAD PLASTIC SO
DD PACKAGE
TJMAX = 150°C, θJA = 250°C/ W
8-LEAD (3mm × 3mm) PLASTIC DFN
TJMAX = 150°C, θJA = 175°C/ W
TJMAX = 125°C, θJA = 160°C/ W (NOTE 2) UNDERSIDE METAL
CONNECTED TO V– (PCB CONNECTION OPTIONAL)
DD
ORDER PART
NUMBER
S8
ORDER PART
NUMBER
ORDER PART
MS8
PART MARKING
PART MARKING*
PART MARKING
NUMBER
LAAS
1540
1540I
LTC1540CDD
LTC1540IDD
LTC1540CS8
LTC1540IS8
LTCE
LTADV
LTC1540CMS8
LTC1540IMS8
Consult LTC Marketing for parts specified with wider operating temperature ranges. *Temperature grades are identified by a label on the shipping container.
The ● denotes the specifications which apply over the full operating
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifications are at TA = 25°C. V+ = 5V, V– = GND = 0V, TA = 25°C unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Power Supply
+
V
Supply Voltage Range
Supply Current
●
2.0
11.0
V
+
–
I
IN = IN = 80mV, HYST = REF, C-Grade
●
●
0.3
0.68
0.71
µA
µA
CC
+
–
IN = IN = 80mV, HYST = REF, I-Grade
Comparator
V
Comparator Input Offset Voltage
V
= 2.5V
CM
±12
±15
±16
mV
mV
mV
OS
●
●
LTC1540CMS8/IMS8
+
–
+
–
I
Input Leakage Current (IN , IN )
Input Leakage Current (HYST)
V
= V = 2.5V
●
●
±0.01
±0.02
±1.0
±1.0
nA
nA
IN
IN
IN
–
+
V
Comparator Input Common Mode Range
Common Mode Rejection Ratio
Power Supply Rejection Ratio
●
V
V – 1.3V
V
mV/V
mV/V
CM
–
+
CMRR
PSRR
V to V – 1.3V
0.1
0.1
1
1
+
V = 2V to 11V
sn1540 1540fas
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LTC1540
The ● denotes the specifications which apply over the full operating
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifications are at TA = 25°C. V+ = 5V, V– = GND = 0V, TA = 25°C unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
Hysteresis Input Voltage Range
Propagation Delay
●
REF – 50mV
REF
V
HYST
t
C
= 100pF
OUT
Overdrive = 10mV
Overdrive = 100mV
60
50
µs
µs
PD
+
V
V
Output High Voltage
Output Low Voltage
I = –13mA
●
●
V – 0.4V
V
V
OH
OL
O
I = 1.8mA
O
GND + 0.4V
Reference
V
Reference Voltage
Load Regulation
No Load
(SO-8)/(DFN) Commercial
MS8 Commercial
(SO-8)/(MS8)/(DFN) Industrial
●
●
●
1.158
1.156
1.152
1.182
1.182
1.182
1.206
1.208
1.212
V
V
V
REF
∆V
0 ≤ I ≤ 100µA
SOURCE
●
0.5
0.5
2.5
mV
REF
0 ≤ I
≤ 10µA
1.5
5
mV
mV
SINK
●
+
–
V
= 3V, V = GND = 0V, T = 25°C unless otherwise noted.
A
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Power Supply
+
V
Supply Voltage Range
Supply Current
●
2
11
V
+
–
I
IN = IN = 80mV, HYST = REF, C-Grade
●
●
0.28
0.61
0.64
µA
µA
CC
+
–
IN = IN = 80mV, HYST = REF, I-Grade
Comparator
V
Comparator Input Offset Voltage
V
= 2.5V
CM
±12
±15
±16
mV
mV
mV
OS
●
●
LTC1540CMS8/IMS8
+
–
+
–
I
Input Leakage Current (IN , IN )
Input Leakage Current (HYST)
V
= V = 1.5V
●
●
±0.01
±0.02
±1
±1
nA
nA
IN
IN
IN
–
+
V
Comparator Input Common Mode Range
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Hysteresis Input Voltage Range
Propagation Delay
●
●
V
V – 1.3V
V
mV/V
mV/V
V
CM
–
+
CMRR
PSRR
V to V – 1.3V
0.1
0.1
1
1
+
V = 2V to 11V
V
REF – 50mV
REF
HYST
t
C
= 100pF
OUT
Overdrive = 10mV
Overdrive = 100mV
70
60
µs
µs
PD
+
V
V
Output High Voltage
Output Low Voltage
I = –8mA
●
●
V – 0.4V
V
V
OH
OL
O
I = 0.8mA
O
GND + 0.4V
Reference
V
Reference Voltage
Load Regulation
No Load
(SO-8)/(DFN) Commercial
MS8 Commercial
(SO-8)/(MS8)/(DFN) Industrial
●
●
●
1.158
1.156
1.152
1.182
1.182
1.182
1.206
1.208
1.212
V
V
V
REF
∆V
0 ≤ I ≤ 100µA
SOURCE
●
0.75
0.5
3.5
mV
REF
0 ≤ I
≤ 10µA
1.5
5
mV
mV
SINK
●
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The θ specified for the DD package is with minimal PCB heat
spreading metal. Using expanded metal area on all layers of a board
reduces this value.
JA
sn1540 1540fas
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LTC1540
TYPICAL PERFORMANCE CHARACTERISTICS
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Reference Voltage
Load Regulation (Sink)
Supply Current vs Temperature
Reference Voltage vs Temperature
0.5
0.4
0.3
0.2
0.1
0
1.190
1.188
1.186
1.184
1.182
1.180
1.178
1.176
1.174
1.172
10
9
8
7
6
5
4
3
2
1
0
+
–
+
–
V
V
= 5V
= GND = 0V
= 25°C
V
V
= 5V
+
V
= 5V
= GND = 0V
–
V
= GND = 0V
T
A
+
V
= 3V
= GND = 0V
–
V
+
–
V
V
= 2V
= GND = 0V
–60
20
TEMPERATURE (°C)
60 80
–60
–20
0
20
80 100
0
20
30 35
–40 –20
0
40
100
–40
40 60
5
10 15
25
40
OUTPUT SINK CURRENT (µA)
TEMPERATURE (°C)
1540 G01
1540 G02
1540 G03
Reference Voltage
Load Regulation (Source)
Comparator Output Voltage (High)
vs Load Current
Comparator Output Voltage (Low)
vs Load Current
5
4
3
2
1
0
5
4
3
2
1
0
2.5
2.0
1.5
1.0
0.5
0
+
–
V
V
= 5V
= GND = 0V
= 25°C
T
= 25°C
T
= 25°C
A
A
+
V
= 5V
T
A
+
+
V
= 5V
V
= 3V
+
V
= 2V
+
V
= 3V
+
V
= 2V
0
2
3
0
30 40 50 60
LOAD CURRENT (mA)
0
10 20 30 40 50 60 70 80
LOAD CURRENT (mA)
1
4
10 20
70 80
OUTPUT SOURCE CURRENT (mA)
1540 G04
1540 G05
1540 G06
Comparator Short-Circuit Current
vs Supply Voltage
Comparator Response Time
vs Input Overdrive
Hysteresis Control
80
60
200
180
160
140
120
100
80
80
75
70
65
60
55
50
45
40
35
30
T
V
V
= 25°C
T
= 25°C
A
A
+
= 5V
–
= GND = 0V
OUTPUT
CONNECTED TO
40
–
V
= GND = 0V;
SOURCE
CURRENT
20
0
t
PLH
OUTPUT
–20
–40
–60
–80
CONNECTED
t
PHL
+
TO V ; SINK
60
CURRENT
40
20
0
10 20 30 40 50 60 70 80 90 100 110
0
1
2
3
4
5
6
7
8
9
10
0
10
20
– V
30
(mV)
40
50
INPUT VOLTAGE (mV)
SUPPLY VOLTAGE (V)
V
REF
HYST
1540 G08
1540 G07
1540 G09
sn1540 1540fas
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LTC1540
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PIN FUNCTIONS
V+ (Pin 7): Positive Supply operating voltage is from 2V
GND (Pin 1): Ground. Connect to V– for single supply
operation.
to 11V.
V– (Pin 2): Negative Supply. Potential should be more
negative than GND. Connect to ground for single supply
operation.
OUT (Pin 8): Comparator CMOS Output. Swings from
GND to V+. Output can source up to 40mA and sink 5mA.
IN+ (Pin 3): Noninverting Comparator Input. Input com-
mon mode range from V– to V+ – 1.3V. Input current
typically 10pA at 25°C.
IN– (Pin 4): Inverting Comparator Input. Input common
mode range from V– to V+ – 1.3V. Input current typically
10pA at 25°C.
1
2
8
7
OUT
LTC1540
GND
–
V
+
V
+
–
+
REF
3
4
IN
6
5
HYST (Pin 5): Hysteresis Input. Connect to REF if not
used. Input voltage range is from VREF to VREF – 50mV.
–
IN
HYST
1540
• PD
REF (Pin 6): Reference Output. 1.182V with respect
to V–. Can source up to 1mA and sink 10µA at 25°C. Drive
0.01µF bypass capacitor without oscillation.
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APPLICATIONS INFORMATION
The LTC1540 is a nanopower comparator with a built-in
1.182Vreference.Featuresincludeprogrammablehyster-
esis, wide supply voltage range (2V to 11V) and the ability
of the reference to drive up to a 0.01µF capacitor without
oscillation. The comparator’s CMOS outputs can source
up to 40mA while supply current glitches that normally
occur when switching logic states, have been eliminated.
Comparator Output
The comparator output swings between GND and V+ to
assure TTL compatibility with a split supply. The output is
capable of sourcing up to 40mA and sinking up to 5mA
while still maintaining nanoampere quiescent currents.
The output stage does not generate crowbar switching
currentsduringtransitionswhichhelpsminimizeparasitic
feedback through the supply pins.
Power Supplies
The comparator operates from a single 2V to 11V supply.
TheLTC1540includesaseparategroundforthecompara-
tor output stage, allowing a split supply ranging from ±1V
to ±5.5V. Connecting V– to GND will allow single supply
operation. If the comparator output is required to source
more than 1mA, or the supply source impedance is high,
V+ should be bypassed with a 0.1µF capacitor.
Voltage Reference
The internal bandgap reference has a voltage of 1.182V
referenced to V–. The reference accuracy is ±2.0% from
0°C to 70°C. It can source up to 1mA and sink up to 10µA
with a 5V supply. The reference can drive a bypass
capacitor of up to 0.01µF without oscillation and by
inserting a series resistor, capacitance values up to 10µF
can be used (Figure 1).
Comparator Inputs
Figure 2 shows the resistor value required for different
capacitor values to achieve critical damping. Bypassing
the reference can help prevent false tripping of the com-
parators by preventing glitches on V+ or reference load
Thecomparatorinputscanswingfromthenegativesupply,
V–, to within 1.3V (max) of the positive supply V+. The
inputs can be forced 300mV below V– or above V+ without
damage and the typical input leakage current is only ±10pA.
transients from disturbing the reference output voltage.
sn1540 1540fas
5
LTC1540
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APPLICATIONS INFORMATION
REFERENCE
OUTPUT
7
+
REF
V
LTC1540
+
–
3
4
5
6
IN
R1
LTC1540
+
–
8
OUT
IN
C1
–
V
5V
TO
8V
HYST
REF
1540 • F01
R2
10k
Figure 1. Damping the Reference Output
R3
2.4M
R1
430Ω
–
GND
1
V
2
1000
100
10
C1
1µF
1540 • F03a
Figure 3a. Power Supply Transient Test Circuit
1
8V
V+
0.1
0.001
0.01
0.1
1
10
5V
CAPACITOR VALUE (µF)
1540 • F02
VREF
Figure 2. Damping Resistance vs Bypass Capacitor Value
OUT
Figure 3 shows the bypassed reference output with a
squarewaveappliedtotheV+ pin. ResistorsR2andR3set
10mV of hysteresis voltage band while R1 damps the
reference response. Note that the comparator output
doesn’t trip.
2ms/DIV
1540 F03b
Figure 3b. Power Supply Transient Rejection
5
–
Low Voltage Operation: V+ = 1.6V
V
= GND = 0V
+
IN = 0V
–
IN = REF = HYST
The guaranteed minimum operating voltage is 2V (or
±1V). As the total supply voltage is reduced below 2V, the
performance degrades and the supply current falls. At low
supply voltages, the comparator’s output drive is reduced
andthepropagationdelayincreases. TheVREF andVOS are
alsoslightlyworse.Theusefulinputvoltagerangeextends
from the negative supply to 0.9V below the positive
supply. Test your prototype over the full
temperature and supply voltage range if operation below
2V is anticipated. Because of the increase in supply
current, operation below 1.5V is not recommended
(Figure 4).
4
3
2
1
0
T
= 25°C
A
0
0.5
1.0
1.5
2.0
2.5
SUPPLY VOLTAGE (V)
1540 F04
Figure 4. Supply Current vs Supply Voltage
sn1540 1540fas
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LTC1540
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APPLICATIONS INFORMATION
Hysteresis
up to 15%. If hysteresis is not wanted, the HYST pin
shouldbeshortedtoREF. AcceptablevaluesforIREF range
from0.1µAto5µA. If2.4MischosenforR2, thenthevalue
of R1 (kΩ) is equal to the value of VHB (mV).
Hysteresis can be added to the LTC1540 by connecting a
resistor (R1) between the REF and HYST pins and a
second resistor (R2) from HYST to V– (Figure 5).
The difference between the upper and lower threshold
voltages,orhysteresisvoltageband(VHB),isequaltotwice
the voltage difference between the REF and HYST pins.
V
(2)(I
HB
R1 =
6
5
REF
)
I
REF
REF
LTC1540
R1
R2
V
2
HB
1.182V –
(
)
HYST
R2 =
I
When more hysteresis is added, the upper threshold
increases the same amount as the low threshold de-
creases. The maximum voltage allowed between REF and
HYST pins is 50mV, producing a maximum hysteresis
voltage band of 100mV. The hysteresis band may vary by
REF
–
V
2
1540 • F05
Figure 5. Programmable Hysteresis
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TYPICAL APPLICATIONS
Level Detector
V
I
1.182V
REF
R1 =
=
= 1.18M
– 1
1µA
BIAS
TheLTC1540isidealforuseasananopowerleveldetector
as shown in Figure 6. R1 and R2 form a voltage divider
from VIN to the noninverting comparator input. R3 and R4
set the hysteresis voltage, and R5 and C1 bypass the
reference output. The following design procedure can be
used to select the component values:
V
IN
R2 = R1
V
2
HB
V
+
REF
4.65V
– 1
R2 = 1.18M
R2 = 3.40M
1. Choose the VIN voltage trip level, in this example 4.65V.
2. Calculate the required resistive divider ratio.
Ratio = VREF/ VIN
15mV
2
1.182V +
Ratio = 1.182V/4.65V = 0.254
V
IN
5V
7
3. Choose the required hysteresis voltage band at the
inputVHBIN,inthisexample60mV.Calculatethehyster-
esis voltage band referred to the comparator input VHB.
R2
3.4M
1%
+
V
LTC1540
+
3
4
5
6
IN
+
8
R1
1.18M
1%
OUT
–
IN
VHB = (VHBIN)(Ratio)
VHB = (60mV)(0.254)
–
HYST
REF
R3
15k
1%
V
HB = 15.24mV
4. Choose the values for R3 and R4 to set the hysteresis.
R4 = 2.4M
R4
2.4M
1%
R5
430Ω
5%
C1
1µF
–
GND
1
V
2
R3 (kΩ) = 15k, VHB (mV) = 15mV
1540 F06
5. Choose the values for R1 and R2 to set the trip point.
Figure 6. Glitch-Free Level Detector with Hysteresis
sn1540 1540fas
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LTC1540
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TYPICAL APPLICATIONS
3.3V Output Low Dropout Linear Regulator
output is the switched power supply output. With a 10mA
load, it typically provides a voltage of (VBAT – 0.17V). The
wholecircuitdrawsamere0.8µAofquiescentcurrentwith
VBAT = 5V. The three resistor voltage divider programs
50mV of hysteresis for the comparator, and sets the IN–
voltage at 200mV. This gives an IN+ trip threshold of
approximately 150mV
The LTC1540 can be connected as a micropower (IQ =
5.5µA at VIN = 5V) low dropout linear regulator (Figure 7).
When the output is low, Q1 turns on, allowing current to
charge output capacitor C1. Local feedback formed by R4,
Q1 and Q2 creates a constant-current source from the 5V
input to C1. R4, R1 and Q2’s VBE also provide current
limitinginthecaseofanoutputshort-circuittoground. C2
reduces output ripple, while the R2-R3 feedback voltage
divider establishes the output voltage.
The RC time constant determines the maximum power-on
timeoftheOUTpinbeforepowerdownoccurs.Thisperiod
can be approximated by:
t = 4.6RC (seconds)
Auto Power-Off Source
The actual time will vary with both the leakage current of
the capacitor and the input current at the IN+ pin.
Figure 8 shows the circuit for a 30mA power supply that
has a timed auto power-off function. The comparator
V
V
= 5V
BAT
IN
R4
10Ω
Q2
7
7
MOMENTARY
2N3906
+
SWITCH
V
+
LTC1540
Q1
TP0610L
V
LTC1540
OUT
+
IN
3
8
+
–
3
4
5
6
IN
IN
R1
+
–
47k
C
R
8
V
OUT
3.3V
C1
+
10µF
OUT
(V
– 0.17V)
BAT
432k
2M
10mA
–
4
5
6
IN
HYST
REF
–
R3
C2
2.2nF
750k
1%
HYST
REF
R2
430k
1%
121k
C3
–
GND
1
V
2
–
GND
1
V
2
1540 F07
1540 F08
Figure 7. 3.3V Output Low Dropout Linear Regulator
Figure 8. Auto Power-Off Switch Operates
on 0.8µA Quiescent Current
sn1540 1540fas
8
LTC1540
U
TYPICAL APPLICATIONS
Low-Battery Detect
operation down to a supply voltage of 2V, but it is still
functional with the supply as low as 1.6V. Some param-
eters, such as VREF and VOS, will be degraded on lower
supply voltages. The input voltage range extends from
0.9V below the positive supply to the negative supply.
Figure 9 shows how to use the LTC1540 for a low-battery
detect, drawing only 1.4µA at VBAT = 2V. The circuit is
powered by a 2-cell NiCd battery. The VBAT pin could be as
low as 1.6V when the batteries are completely depleted.
The electrical specifications of the LTC1540 guarantee
V
= ~1.6V TO 2.5V
BAT
2-CELL
NiCd
7
R1
+
V
LTC1540
OUT
3M
+
3
4
6
5
IN
IN
+
–
8
R2
1.1M
LBO
–
REF
R3
40k
HYST
R4
1.2M
–
GND
1
V
2
R5
1M
1540 F09
Figure 9. Low-Battery Detect Works Down to 1.6V
sn1540 1540fas
9
LTC1540
PACKAGE DESCRIPTION
U
DD Package
8-Lead Plastic DFN (3mm × 3mm)
(Reference LTC DWG # 05-08-1698)
R = 0.115
0.38 ± 0.10
TYP
5
8
0.675 ±0.05
3.5 ±0.05
2.15 ±0.05 (2 SIDES)
1.65 ±0.05
3.00 ±0.10
(4 SIDES)
1.65 ± 0.10
(2 SIDES)
PIN 1
TOP MARK
PACKAGE
OUTLINE
(DD8) DFN 0203
4
1
0.28 ± 0.05
0.75 ±0.05
0.200 REF
0.28 ± 0.05
0.50 BSC
0.50
BSC
2.38 ±0.05
(2 SIDES)
2.38 ±0.10
(2 SIDES)
0.00 – 0.05
BOTTOM VIEW—EXPOSED PAD
NOTE:
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1)
2. ALL DIMENSIONS ARE IN MILLIMETERS
3. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
4. EXPOSED PAD SHALL BE SOLDER PLATED
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660)
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
0.889 ± 0.127
(.035 ± .005)
0.52
(.206)
REF
8
7 6
5
5.23
(.206)
MIN
3.2 – 3.45
(.126 – .136)
3.00 ± 0.102
(.118 ± .004)
NOTE 4
4.90 ± 0.15
(1.93 ± .006)
DETAIL “A”
0° – 6° TYP
0.254
(.010)
GAUGE PLANE
0.65
(.0256)
BSC
0.42 ± 0.04
1
2
3
4
(.0165 ± .0015)
TYP
0.53 ± 0.015
(.021 ± .006)
1.10
(.043)
MAX
0.86
(.034)
REF
RECOMMENDED SOLDER PAD LAYOUT
DETAIL “A”
0.18
(.077)
SEATING
PLANE
NOTE:
0.22 – 0.38
(.009 – .015)
TYP
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
0.13 ± 0.076
(.005 ± .003)
0.65
(.0256)
BSC
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
MSOP (MS8) 0802
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
sn1540 1540fas
10
LTC1540
U
PACKAGE DESCRIPTION
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.189 – .197
(4.801 – 5.004)
.045 ±.005
.160 ±.005
NOTE 3
.050 BSC
7
5
8
6
.245
MIN
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
.030 ±.005
TYP
1
3
4
2
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
(0.254 – 0.508)
× 45°
.053 – .069
(1.346 – 1.752)
.004 – .010
(0.101 – 0.254)
.008 – .010
(0.203 – 0.254)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
.050
(1.270)
BSC
.014 – .019
(0.355 – 0.483)
TYP
NOTE:
INCHES
1. DIMENSIONS IN
(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)
SO8 0303
sn1540 1540fas
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 represen-
tationthattheinterconnectionofitscircuitsasdescribedhereinwillnotinfringeonexistingpatentrights.
11
LTC1540
U
TYPICAL APPLICATION
RF Field Detector
Figure 10 shows the complete circuit for a field detector The rectified output is monitored by the LTC1540 com-
which was tested at 445MHz. A transmission line is used parator. The internal reference is used to set up a threshold
to match the detector diode (1N5712) to a quarter-wave of about 18mV at the inverting input. A rising edge at the
whip antenna. The 0.23λ wavelength transmission line comparator output triggers a one shot that temporarily
section transforms the 1pF (350Ω) diode junction capaci- enables answer back and any other pulsed functions.
tance to a virtual short at the base of the antenna. At the
Thetotalsupplycurrentis400nA. Amongothermonolithic
same time it converts the received antenna current to a
one shots, the CD4047 draws the least amount of transient
voltage loop at the diode, giving excellent sensitivity.
current.
2V TO 11V
λ/4
12M
5
FB
10k
6
3
4
7
+
Q
Q
CMOS
ONE SHOT
(CD4047)
8
10nF
LTC1540
–
0.23λ
1
2
10nF
180k
1540 F10
1N5712
Figure 10. Nanopower Field Detector
RELATED PARTS
PART NUMBER
LT®1178/LT1179
LT1351
DESCRIPTION
COMMENTS
70µV Max V , 5nA Max I
C-LoadTM Op Amp Stable Driving Any Capacitive Load
C-LoadOp Amps Stable Driving Any Capacitive Load
1.182V ±1% Reference, ±10mV (Max) Input Offset
Dual/Quad 17µA Precision Single Supply Op Amps
Single 250µA, 3MHz, 200V/µs Op Amp with Shutdown
Dual/Quad 250µA, 3MHz, 200V/µs Op Amps
Micropower Comparator with 1% Reference
OS
BIAS
LT1352/LT1353
LTC1440
LTC1443/LTC1444/LTC1445 Micropower Quad Comparators with 1% Reference
LTC1443 Has 1.182V Reference, LTC1444/LTC1445 Have
1.221V Reference and Adjustable Hysteresis
LTC1474
LT1495
LT1521
LT1634
Low Quiescent Current High Efficiency
Step-Down Converter
10µA Standby Current, 92% Efficiency, Space Saving 8-Pin
MSOP Package
1.5µA Max, Dual Precision Rail-to-Rail
Input and Output Op Amp
375µV Max V , 250pA I
, 25pA I
BIAS OS
OS
300mA Low Dropout Regulator with Micropower
Quiescent Current and Shutdown
0.5V Dropout Voltage, 12µA Quiescent Current, Adjustable
Output 3V, 3.3V and 5V Fixed
Micropower Precision Shunt Voltage Reference
1.25V, 2.5V, 4.096V, 5V Outputs, 10µA Operating Current,
0.05% Initial Accuracy 25ppm/°C Max Drift, SO-8, MSOP and
TO-92 Packages
C-Load is a trademark of Linear Technology Corporation.
sn1540 1540fas
LT/TP 0403 1K REV A • PRINTED IN USA
LinearTechnology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
12
●
●
©LINEAR TECHNOLOGY CORPORATION 1997
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
相关型号：
LT1179ACN#PBF
LT1179 - 17µA Max, Quad, Single Supply, Precision Op Amps; Package: PDIP; Pins: 14; Temperature Range: 0°C to 70°C
Linear
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