công cụ tìm kiếm bảng dữ liệu linh kiện điện tử |
|
MC74AC257DTR2G bảng dữ liệu(PDF) 2 Page - ON Semiconductor |
|
MC74AC257DTR2G bảng dữ liệu(HTML) 2 Page - ON Semiconductor |
2 / 9 page MC74AC257, MC74ACT257 www.onsemi.com 2 PIN NAME PIN FUNCTION S Common Data Select Input OE 3−State Output Enable Input I0a−I0d Data Inputs from Source 0 I1a−I1d Data Inputs from Source 1 Za−Zd 3−State Multiplexer Outputs TRUTH TABLE Output Enable Select Input Data Inputs Outputs OE S I0 I1 Z H X X X Z L H X LL L H X HH L L L XL L L H X H H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial Z = High Impedance Figure 2. Logic Symbol S OE I0a I1a I0b I1b Zb I0c I1c I0d I1d Za Zc Zd FUNCTIONAL DESCRIPTION The MC74AC257/74ACT257 is a quad 2−input multiplexer with 3−state outputs. It selects four bits of data from two sources under control of a Common Data Select input. When the Select input is LOW, the I0x inputs are selected and when Select is HIGH, the I1x inputs are selected. The data on the selected inputs appears at the outputs in true (noninverted) form. The device is the logic implementation of a 4−pole, 2−position switch where the position of the switch is determined by the logic levels supplied to the Select input. The logic equations for the outputs are shown below: Za = OE•(I1a•S+I0a•S) Zb = OE•(I1b•S+I0b•S) Zc = OE•(I1c•S+I0c•S) Zd = OE•(I1d•S+I0d•S) When the Output Enable input (OE) is HIGH, the outputs are forced to a high impedance state. If the outputs are tied together, all but one device must be in the high impedance state to avoid high currents that would exceed the maximum ratings. Designers should ensure the Output Enable signals to 3−state devices whose outputs are tied together are designed so there is no overlap. NOTE: This diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays. OE I0a I1a I0b I1b I0c I1c I0d I1d S Za Zb Zc Zd Figure 3. Logic Diagram |
Số phần tương tự - MC74AC257DTR2G |
|
Mô tả tương tự - MC74AC257DTR2G |
|
|
Link URL |
Chính sách bảo mật |
ALLDATASHEET.VN |
Cho đến nay ALLDATASHEET có giúp ích cho doanh nghiệp của bạn hay không? [ DONATE ] |
Alldatasheet là | Quảng cáo | Liên lạc với chúng tôi | Chính sách bảo mật | Trao đổi link | Tìm kiếm theo nhà sản xuất All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |