參數(shù)資料
型號(hào)： HD40C4389
廠商： Hitachi,Ltd.
英文描述： Low-Voltage AS Microcomputers with On-Chip A/D Converter(帶片上A/D轉(zhuǎn)換器的低壓微計(jì)算機(jī))
中文描述： 低電壓如同在微機(jī)芯片的A / D轉(zhuǎn)換器（帶片上的A / D轉(zhuǎn)換器的低壓微計(jì)算機(jī)）
文件頁數(shù)： 122/162頁
文件大?。?/td> 482K
代理商： HD40C4389
HD404374/HD404384/HD404389/HD404082/HD404084 Series
122
Notes on PROM Programming
Principles of Programming/Erasure:
A memory cell in a ZTAT microcomputer is the same as an
EPROM cell; it is programmed by applying a high voltage between its control gate and drain to inject hot
electrons into its floating gate. These electrons are stable, surrounded by an energy barrier formed by an
SiO
2
film. The change in threshold voltage of a memory cell with a charged floating gate makes the
corresponding bit appear as 0; a cell whose floating gate is not charged appears as a 1 bit (figure 73).
The charge in a memory cell may decrease with time. This decrease is usually due to one of the following
causes:
Ultraviolet light excites electrons, allowing them to escape. This effect is the basis of the erasure
principle.
Heat excites trapped electrons, allowing them to escape.
High voltages between the control gate and drain may erase electrons.
If the oxide film covering a floating gate is defective, the electron erasure rate will be greater. However,
electron erasure does not often occur because defective devices are detected and removed at the testing
stage.
Control gate
Floating gate
Drain
SiO
2
Source
N
N
+
+
Control gate
Floating gate
Drain
SiO
2
Source
N
N
+
+
Erasure (1)
Write (0)
Figure 73 Cross-Sections of a PROM Cell
PROM Programming:
PROM memory cells must be programmed under specific voltage and timing
conditions. The higher the programming voltage V
PP
and the longer the programming pulse t
PW
is applied,
the more electrons are injected into the floating gates. However, if V
PP
exceeds specifications, the pn
junctions may be permanently damaged. Pay particular attention to overshooting in the PROM
programmer. In addition, note that negative voltage noise will produce a parasitic transistor effect that may
reduce breakdown voltages.
The ZTAT microcomputer is electrically connected to the PROM programmer by a socket adapter.
Therefore, note the following points:
Check that the socket adapter is firmly mounted on the PROM programmer.
Do not touch the socket adapter or the LSI during the programming. Touching them may affect the
quality of the contacts, which will cause programming errors.
相關(guān)PDF資料
PDF描述
HD404394 4-bit HMCS400-series microcomputer(4位單片微計(jì)算機(jī))
HD4074344S 4-bit HMCS400-series microcomputer(4位單片微計(jì)算機(jī))
HD4074394S 4-bit HMCS400-series microcomputer(4位單片微計(jì)算機(jī))
HD40C4341R 4-bit HMCS400-series microcomputer(4位單片微計(jì)算機(jī))
HD40C4342R 4-bit HMCS400-series microcomputer(4位單片微計(jì)算機(jī))
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
HD40L4818H 制造商:Renesas Electronics Corporation 功能描述:
HD40-M 制造商:Tamura Corporation of America 功能描述:
HD40WS/EHOOD/PLUG 制造商:Lapp 功能描述:HD 40 way side entry assembled plug 制造商:Lapp Group 功能描述:HD 40 way side entry assembled plug
HD-41494-1 功能描述:環(huán)形MIL規(guī)格工具、五金與附件 RoHS:否 制造商:Amphenol Industrial MIL 類型:MIL-DTL-5015 系列:97 產(chǎn)品類型:Dummy Receptacles 用于:97 Series Plugs
HD4-15530/883 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Encoder/Decoder
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。

采購需求

(若只采購一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購

我的聯(lián)系方式

*
*
*