參數(shù)資料
型號: 74ALVC74
廠商: NXP Semiconductors N.V.
英文描述: Dual D-type flip-flop with set and reset; positive-edge trigger
中文描述: 帶設(shè)置和復(fù)位功能的雙D觸發(fā)器;上升沿觸發(fā)
文件頁數(shù): 15/20頁
文件大?。?/td> 103K
代理商: 74ALVC74
2003 May 26
15
Philips Semiconductors
Product specification
Dual D-type flip-flop with set and reset;
positive-edge trigger
74ALVC74
SOLDERING
Introduction to soldering surface mount packages
Thistextgivesaverybriefinsighttoacomplextechnology.
A more in-depth account of soldering ICs can be found in
our “Data Handbook IC26; Integrated Circuit Packages”
(document order number 9398 652 90011).
There is no soldering method that is ideal for all surface
mount IC packages. Wave soldering can still be used for
certainsurfacemountICs,butitisnotsuitableforfinepitch
SMDs. In these situations reflow soldering is
recommended.
Reflow soldering
Reflow soldering requires solder paste (a suspension of
fine solder particles, flux and binding agent) to be applied
to the printed-circuit board by screen printing, stencilling or
pressure-syringe dispensing before package placement.
Driven by legislation and environmental forces the
worldwide use of lead-free solder pastes is increasing.
Several methods exist for reflowing; for example,
convection or convection/infrared heating in a conveyor
type oven. Throughput times (preheating, soldering and
cooling) vary between 100 and 200 seconds depending
on heating method.
Typical reflow peak temperatures range from
215 to 270
°
C depending on solder paste material. The
top-surface temperature of the packages should
preferably be kept:
below 220
°
C (SnPb process) or below 245
°
C (Pb-free
process)
– for all the BGA packages
– for packages with a thickness
2.5 mm
– for packages with a thickness < 2.5 mm and a
volume
350 mm
3
so called thick/large packages.
below 235
°
C (SnPb process) or below 260
°
C (Pb-free
process) for packages with a thickness < 2.5 mm and a
volume < 350 mm
3
so called small/thin packages.
Moisture sensitivity precautions, as indicated on packing,
must be respected at all times.
Wave soldering
Conventional single wave soldering is not recommended
forsurfacemountdevices(SMDs)orprinted-circuitboards
with a high component density, as solder bridging and
non-wetting can present major problems.
To overcome these problems the double-wave soldering
method was specifically developed.
If wave soldering is used the following conditions must be
observed for optimal results:
Use a double-wave soldering method comprising a
turbulent wave with high upward pressure followed by a
smooth laminar wave.
For packages with leads on two sides and a pitch (e):
– larger than or equal to 1.27 mm, the footprint
longitudinal axis is
preferred
to be parallel to the
transport direction of the printed-circuit board;
– smaller than 1.27 mm, the footprint longitudinal axis
must
be parallel to the transport direction of the
printed-circuit board.
The footprint must incorporate solder thieves at the
downstream end.
Forpackageswithleadsonfoursides,thefootprintmust
be placed at a 45
°
angle to the transport direction of the
printed-circuit board. The footprint must incorporate
solder thieves downstream and at the side corners.
During placement and before soldering, the package must
be fixed with a droplet of adhesive. The adhesive can be
applied by screen printing, pin transfer or syringe
dispensing. The package can be soldered after the
adhesive is cured.
Typical dwell time of the leads in the wave ranges from
3 to 4 seconds at 250
°
C or 265
°
C, depending on solder
material applied, SnPb or Pb-free respectively.
A mildly-activated flux will eliminate the need for removal
of corrosive residues in most applications.
Manual soldering
Fix the component by first soldering two
diagonally-opposite end leads. Use a low voltage (24 V or
less) soldering iron applied to the flat part of the lead.
Contact time must be limited to 10 seconds at up to
300
°
C.
When using a dedicated tool, all other leads can be
soldered in one operation within 2 to 5 seconds between
270 and 320
°
C.
相關(guān)PDF資料
PDF描述
74ALVCH162244 16-bit buffer/line driver with 30Ω termination resistor (3-State)(帶30Ω終端電阻器的16位緩沖器/線驅(qū)動器(三態(tài)))
74ALVCH162245 16-bit bus transceiver with direction pin and 30Ω termination resistor (3-State)(帶30Ω終端電阻器和定向引腳的16位總線收發(fā)器(三態(tài)))
74ALVCH16244 16-bit buffer/line driver (3-State)(16位緩沖器/線驅(qū)動器(三態(tài)))
74ALVC16244 Triple 3-Input Positive-NAND Gates 14-TSSOP -40 to 85
74ALVC16244 Triple 3-Input Positive-NAND Gates 14-TSSOP -40 to 85
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
74ALVC74AMDC 制造商:Integrated Device Technology Inc 功能描述:
74ALVC74BQ 制造商:NXP Semiconductors 功能描述:IC DUAL D F-F POS EDGE DHV
74ALVC74BQ,115 功能描述:觸發(fā)器 DUAL D-TYPE POSITIVE RoHS:否 制造商:Texas Instruments 電路數(shù)量:2 邏輯系列:SN74 邏輯類型:D-Type Flip-Flop 極性:Inverting, Non-Inverting 輸入類型:CMOS 輸出類型: 傳播延遲時間:4.4 ns 高電平輸出電流:- 16 mA 低電平輸出電流:16 mA 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:X2SON-8 封裝:Reel
74ALVC74BQ115 制造商:NXP Semiconductors 功能描述:
74ALVC74BQ-G 功能描述:觸發(fā)器 DUAL D-TYPE POSITIVE EDGE-TRIG RoHS:否 制造商:Texas Instruments 電路數(shù)量:2 邏輯系列:SN74 邏輯類型:D-Type Flip-Flop 極性:Inverting, Non-Inverting 輸入類型:CMOS 輸出類型: 傳播延遲時間:4.4 ns 高電平輸出電流:- 16 mA 低電平輸出電流:16 mA 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:X2SON-8 封裝:Reel