參數(shù)資料
型號: SN74LVTH646DGVRE4
廠商: TEXAS INSTRUMENTS INC
元件分類: 總線收發(fā)器
英文描述: LVT SERIES, 8-BIT REGISTERED TRANSCEIVER, TRUE OUTPUT, PDSO24
封裝: GREEN, PLASTIC, TVSOP-24
文件頁數(shù): 12/21頁
文件大?。?/td> 579K
代理商: SN74LVTH646DGVRE4
SN54LVTH646, SN74LVTH646
3.3V ABT OCTAL BUS TRANSCEIVERS AND REGISTERS
WITH 3STATE OUTPUTS
SCBS705H AUGUST 1997 REVISED MAY 2004
2
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
description/ordering information (continued)
The ’LVTH646 devices consist of bus transceiver circuits, D-type flip-flops, and control circuitry arranged for
multiplexed transmission of data directly from the input bus or from the internal registers. Data on the A or B
bus is clocked into the registers on the low-to-high transition of the appropriate clock (CLKAB or CLKBA) input.
Figure 1 illustrates the four fundamental bus-management functions that can be performed with the ’LVTH646.
Output-enable (OE) and direction-control (DIR) inputs are provided to control the transceiver functions. In the
transceiver mode, data present at the high-impedance port can be stored in either register or in both.
The select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) data. The
direction control (DIR) determines which bus receives data when OE is low. In the isolation mode (OE high),
A data can be stored in one register and/or B data can be stored in the other register.
When an output function is disabled, the input function still is enabled and can be used to store and transmit
data. Only one of the two buses, A or B, can be driven at a time.
Active bus-hold circuitry is provided to hold unused or floating data inputs at a valid logic level. Use of pullup
or pulldown resistors with the bus-hold circuitry is not recommended.
To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
These devices are fully specified for hot-insertion applications using Ioff and power-up 3-state. The Ioff circuitry
disables the outputs, preventing damaging current backflow through the devices when they are powered down.
The power-up 3-state circuitry places the outputs in the high-impedance state during power up and power down,
which prevents driver conflict.
FUNCTION TABLE
INPUTS
DATA I/Os
OPERATION OR FUNCTION
OE
DIR
CLKAB
CLKBA
SAB
SBA
A1A8
B1B8
OPERATION OR FUNCTION
X
X
Input
Unspecified
Store A, B unspecified
X
XX
X
Unspecified
Input
Store B, A unspecified
H
X
X
Input
Store A and B data
H
X
H or L
X
Input disabled
Isolation, hold storage
L
X
L
Output
Input
Real-time B data to A bus
L
X
H or L
X
H
Output
Input
Stored B data to A bus
L
H
X
L
X
Input
Output
Real-time A data to B bus
L
H
H or L
X
H
X
Input
Output
Stored A data to B bus
The data-output functions can be enabled or disabled by various signals at OE and DIR. Data-input functions always are enabled; i.e., data at
the bus terminals is stored on every low-to-high transition of the clock inputs.
相關(guān)PDF資料
PDF描述
SN74LVTH646NSRE4 LVT SERIES, 8-BIT REGISTERED TRANSCEIVER, TRUE OUTPUT, PDSO24
SN74LVTH652DWRG4 LVT SERIES, 8-BIT REGISTERED TRANSCEIVER, TRUE OUTPUT, PDSO24
SN74LVTH652PWG4 LVT SERIES, 8-BIT REGISTERED TRANSCEIVER, TRUE OUTPUT, PDSO24
SN74LVTH652NSRG4 LVT SERIES, 8-BIT REGISTERED TRANSCEIVER, TRUE OUTPUT, PDSO24
SN74LVTZ244PWLE LVT SERIES, DUAL 4-BIT DRIVER, TRUE OUTPUT, PDSO20
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
SN74LVTH646DGVRG4 功能描述:總線收發(fā)器 3.3V ABT Octal Bus Transceivr Registr RoHS:否 制造商:Fairchild Semiconductor 邏輯類型:CMOS 邏輯系列:74VCX 每芯片的通道數(shù)量:16 輸入電平:CMOS 輸出電平:CMOS 輸出類型:3-State 高電平輸出電流:- 24 mA 低電平輸出電流:24 mA 傳播延遲時間:6.2 ns 電源電壓-最大:2.7 V, 3.6 V 電源電壓-最小:1.65 V, 2.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-48 封裝:Reel
SN74LVTH646DW 功能描述:總線收發(fā)器 Tri-St ABT Octal Bus RoHS:否 制造商:Fairchild Semiconductor 邏輯類型:CMOS 邏輯系列:74VCX 每芯片的通道數(shù)量:16 輸入電平:CMOS 輸出電平:CMOS 輸出類型:3-State 高電平輸出電流:- 24 mA 低電平輸出電流:24 mA 傳播延遲時間:6.2 ns 電源電壓-最大:2.7 V, 3.6 V 電源電壓-最小:1.65 V, 2.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-48 封裝:Reel
SN74LVTH646DWE4 功能描述:總線收發(fā)器 3.3V ABT Octal Bus Xcvr/Reg RoHS:否 制造商:Fairchild Semiconductor 邏輯類型:CMOS 邏輯系列:74VCX 每芯片的通道數(shù)量:16 輸入電平:CMOS 輸出電平:CMOS 輸出類型:3-State 高電平輸出電流:- 24 mA 低電平輸出電流:24 mA 傳播延遲時間:6.2 ns 電源電壓-最大:2.7 V, 3.6 V 電源電壓-最小:1.65 V, 2.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-48 封裝:Reel
SN74LVTH646DWG4 功能描述:總線收發(fā)器 3.3V ABT Octal Bus Transceivr Registr RoHS:否 制造商:Fairchild Semiconductor 邏輯類型:CMOS 邏輯系列:74VCX 每芯片的通道數(shù)量:16 輸入電平:CMOS 輸出電平:CMOS 輸出類型:3-State 高電平輸出電流:- 24 mA 低電平輸出電流:24 mA 傳播延遲時間:6.2 ns 電源電壓-最大:2.7 V, 3.6 V 電源電壓-最小:1.65 V, 2.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-48 封裝:Reel
SN74LVTH646DWR 功能描述:總線收發(fā)器 3.3V ABT Octal Bus Xcvr/Reg RoHS:否 制造商:Fairchild Semiconductor 邏輯類型:CMOS 邏輯系列:74VCX 每芯片的通道數(shù)量:16 輸入電平:CMOS 輸出電平:CMOS 輸出類型:3-State 高電平輸出電流:- 24 mA 低電平輸出電流:24 mA 傳播延遲時間:6.2 ns 電源電壓-最大:2.7 V, 3.6 V 電源電壓-最小:1.65 V, 2.3 V 最大工作溫度:+ 85 C 封裝 / 箱體:TSSOP-48 封裝:Reel