參數(shù)資料
型號(hào): 74HCT7273
廠商: NXP Semiconductors N.V.
英文描述: Dual 4-Input Positive-NAND Gates 14-SO -40 to 85
中文描述: 八路D型觸發(fā)器的復(fù)位觸發(fā)器,上升沿觸發(fā);開漏輸出
文件頁數(shù): 14/20頁
文件大?。?/td> 91K
代理商: 74HCT7273
1999 Oct 01
14
Philips Semiconductors
Product specification
Octal D-type flip-flop with reset; positive
edge-trigger; open drain outputs
74HCT7273
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 is not always suitable
for surface mount ICs, or for printed-circuit boards with
high population densities. In these situations reflow
soldering is often used.
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.
Several methods exist for reflowing; for example,
infrared/convection 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 250
°
C. The top-surface temperature of the
packages should preferable be kept below 230
°
C.
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 is 4 seconds at 250
°
C.
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.
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
74HCT7273(SMD) 制造商:MISCELLANEOUS 功能描述:
74HCT7273D 功能描述:觸發(fā)器 OCTAL D FF POS-EDGE 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(shí)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(fēng)格:SMD/SMT 封裝 / 箱體:X2SON-8 封裝:Reel
74HCT7273D,112 功能描述:觸發(fā)器 OCTAL D FF POS-EDGE 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(shí)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(fēng)格:SMD/SMT 封裝 / 箱體:X2SON-8 封裝:Reel
74HCT7273D,118 功能描述:觸發(fā)器 OCTAL D FLIP-FLOP 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(shí)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(fēng)格:SMD/SMT 封裝 / 箱體:X2SON-8 封裝:Reel
74HCT7273D-T 功能描述:觸發(fā)器 OCTAL D FLIP-FLOP 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(shí)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(fēng)格:SMD/SMT 封裝 / 箱體:X2SON-8 封裝:Reel