SN74ALS990 具有三态输出的二路 4 位 D 类锁存器
This 8-bit latch is designed specifically for storing the contents of the input data bus and providing the capability of reading back the stored data onto the input data bus.
The eight latches are transparent D-type latches. While the latch-enable (LE) input is high, the Q outputs follow the data (D) inputs.
Read back is provided through the output-enable (
) input. When is taken low, the data present at the output of the data latches is allowed to pass back onto the input data bus. When is taken high, the output of the data latches is isolated from the D inputs. does not affect the internal operation of the latches; however, precautions should be taken not to create a bus conflict
| SN74ALS990 | |
| Voltage Nodes(V) | 5 |
| Technology Family | ABT |
| Rating | Catalog |
SN74ALS990 特性
- 3-State I/O-Type Read-Back Inputs
- Bus-Structured Pinout
- True Logic Outputs
- Package Options Include Plastic Small-Outline (DW) Packages and Standard Plastic (N) 300-mil DIPs
SN74ALS990 芯片订购指南
| 器件 | 状态 | 温度 | 价格（美元） | 封装 | 引脚 | 封装数量 | 封装载体 | 丝印标记 |
| SN74ALS990DW | ACTIVE | 0 to 70 | 12.00 | 1ku | SOIC (DW) | 20 | 25 | TUBE | |
| SN74ALS990DWE4 | ACTIVE | 0 to 70 | 12.00 | 1ku | SOIC (DW) | 20 | 25 | TUBE | |
| SN74ALS990DWG4 | ACTIVE | 0 to 70 | 12.00 | 1ku | SOIC (DW) | 20 | 25 | TUBE | |
| SN74ALS990DWR | ACTIVE | 0 to 70 | 10.00 | 1ku | SOIC (DW) | 20 | 2000 | LARGE T&R | |
| SN74ALS990DWRE4 | ACTIVE | 0 to 70 | 10.00 | 1ku | SOIC (DW) | 20 | 2000 | LARGE T&R | |
| SN74ALS990DWRG4 | ACTIVE | 0 to 70 | 10.00 | 1ku | SOIC (DW) | 20 | 2000 | LARGE T&R | |
| SN74ALS990NT | ACTIVE | 0 to 70 | 11.35 | 1ku | PDIP (NT) | 20 | 15 | TUBE | |
| SN74ALS990NTE4 | ACTIVE | 0 to 70 | 11.35 | 1ku | PDIP (NT) | 20 | 15 | TUBE |
SN74ALS990 质量与无铅数据
| 器件 | 环保计划* | 铅/焊球涂层 | MSL 等级/回流焊峰 | 环保信息与无铅 (Pb-free) | DPPM / MTBF / FIT 率 |
| SN74ALS990DW | Green (RoHS & no Sb/Br) | CU NIPDAU | Level-1-260C-UNLIM | SN74ALS990DW | SN74ALS990DW |
| SN74ALS990DWE4 | Green (RoHS & no Sb/Br) | CU NIPDAU | Level-1-260C-UNLIM | SN74ALS990DWE4 | SN74ALS990DWE4 |
| SN74ALS990DWG4 | Green (RoHS & no Sb/Br) | CU NIPDAU | Level-1-260C-UNLIM | SN74ALS990DWG4 | SN74ALS990DWG4 |
| SN74ALS990DWR | Green (RoHS & no Sb/Br) | CU NIPDAU | Level-1-260C-UNLIM | SN74ALS990DWR | SN74ALS990DWR |
| SN74ALS990DWRE4 | Green (RoHS & no Sb/Br) | CU NIPDAU | Level-1-260C-UNLIM | SN74ALS990DWRE4 | SN74ALS990DWRE4 |
| SN74ALS990DWRG4 | Green (RoHS & no Sb/Br) | CU NIPDAU | Level-1-260C-UNLIM | SN74ALS990DWRG4 | SN74ALS990DWRG4 |
| SN74ALS990NT | Pb-Free (RoHS) | CU NIPDAU | Level-1-260C-UNLIM | SN74ALS990NT | SN74ALS990NT |
| SN74ALS990NTE4 | Pb-Free (RoHS) | CU NIPDAU | Level-1-260C-UNLIM | SN74ALS990NTE4 | SN74ALS990NTE4 |
SN74ALS990 应用技术支持与电子电路设计开发资源下载
- SN74ALS990 数据资料 dataSheet 下载.PDF
- TI 德州仪器触发器/锁存器/寄存器产品选型与价格 . xls
- Shelf-Life Evaluation of Lead-Free Component Finishes (PDF 1305 KB)
- Understanding and Interpreting Standard-Logic Data Sheets (PDF 857 KB)
- TI IBIS File Creation, Validation, and Distribution Processes (PDF 380 KB)
- Implications of Slow or Floating CMOS Inputs (PDF 101 KB)
- CMOS Power Consumption and CPD Calculation (PDF 89 KB)
- Designing With Logic (PDF 186 KB)
- Live Insertion (PDF 150 KB)
- Input and Output Characteristics of Digital Integrated Circuits (PDF 1708 KB)
- Using High Speed CMOS and Advanced CMOS in Systems With Multiple Vcc (PDF 43 KB)
- HiRel Unitrode Power Management Brochure (PDF 206 KB)
- LOGIC Pocket Data Book (PDF 6001 KB)
- HiRel Unitrode Power Management Brochure (PDF 206 KB)
- Logic Cross-Reference (PDF 2938 KB)