参数资料
型号: LT1794
厂商: Linear Technology Corporation
英文描述: Dual 500mA, 200MHz xDSL Line Driver Amplifier
中文描述: 双500mA的,200MHz的xDSL线路驱动放大器
文件页数: 9/20页
文件大小: 275K
代理商: LT1794
9
LT1794
Two Control Inputs
RESISTOR VALUES (k
)
R
SHDN
TO V
CC
(12V)
3V
40.2
11.5
19.1
22.1
SUPPLY CURRENT PER AMPLIFIER (mA)
R
SHDN
TO V
LOGIC
3V
4.99
8.66
14.3
17.8
V
LOGIC
R
SHDN
R
C1
R
CO
V
C0
H
L
H
L
3.3V
43.2
13.0
5V
60.4
21.5
36.5
3.3V
6.81
10.7
5V
19.6
20.5
34.0
V
C1
H
H
L
L
10
7
5
2
10
7
5
2
10
7
5
2
10
7
5
2
10
7
5
2
10
7
5
2
One Control Input
RESISTOR VALUES (k
)
R
SHDN
TO V
CC
(12V)
3V
40.2
7.32
8.25
SUPPLY CURRENT PER AMPLIFIER (mA)
R
SHDN
TO V
LOGIC
3V
4.99
5.49
6.65
V
LOGIC
R
SHDN
R
C
V
C
H
L
3.3V
43.2
5V
60.4
13.7
3.3V
6.81
5V
19.6
12.7
10
2
10
2
10
2
10
2
10
2
10
2
R
SHDN
R
C1
V
C1
V
LOGIC
12V OR V
LOGIC
0V
V
C0
R
C0
SHDN
SHDNREF
2k
R
SHDN
R
C
V
C
V
LOGIC
12V OR V
LOGIC
0V
SHDN
SHDNREF
1794 F04
2k
APPLICATIOU
Logic Controlled Operating Current
The DSP controller in a typical xDSL application can have
I/O pins assigned to provide logic control of the LT1794
line driver operating current. As shown in Figure 4 one or
two logic control inputs can control two or four different
operating modes. The logic inputs add or subtract current
to the SHDN input to set the operating current. The one
logic input example selects the supply current to be either
full power, 10mA per amplifier or just 2mA per amplifier,
which significantly reduces the driver power consumption
while maintaining less than 2
output impedance to
frequencies less than 1MHz. This low power mode retains
termination impedance at the amplifier outputs and the
line driving back termination resistors. With this termina-
tion, while a DSL port is not transmitting data, it can still
sense a received signal from the line across the back-
termination resistors and respond accordingly.
The two logic input control provides two intermediate
(approximately 7mA per amplifier and 5mA per amplifier)
operating levels between full power and termination modes.
These modes can be useful for overall system power
management when full power transmissions are not
necessary.
W
U
U
Shutdown and Recovery
The ultimate power saving action on a completely idle port
is to fully shut down the line driver by pulling the SHDN pin
to within 0.4V of the SHDNREF potential. As shown in
Figure 5 complete shutdown occurs in less than 10
μ
s and,
more importantly, complete recovery from the shut down
state to full operation occurs in less than 2
μ
s. The biasing
circuitry in the LT1794 reacts very quickly to bring the
amplifiers back to normal operation.
Figure 4. Providing Logic Input Control of Operating Current
V
SHDNREF = 0V
AMPLIFIER
OUTPUT
1794 F05
Figure 5. Shutdown and Recovery Timing
相关PDF资料
PDF描述
LT1794CFE Dual 500mA, 200MHz xDSL Line Driver Amplifier
LT1794CSW Dual 500mA, 200MHz xDSL Line Driver Amplifier
LT1794IFE Dual 500mA, 200MHz xDSL Line Driver Amplifier
LT1796 Overvoltage Fault Protected CAN Transceiver
LT1796CN8 Overvoltage Fault Protected CAN Transceiver
相关代理商/技术参数
参数描述
LT1794CFE 功能描述:IC AMP XDSL LINE DRIVER 20TSSOP RoHS:否 类别:集成电路 (IC) >> 接口 - 驱动器,接收器,收发器 系列:- 标准包装:27 系列:- 类型:收发器 驱动器/接收器数:3/3 规程:RS232,RS485 电源电压:4.75 V ~ 5.25 V 安装类型:表面贴装 封装/外壳:28-SOIC(0.295",7.50mm 宽) 供应商设备封装:28-SOIC 包装:管件
LT1794CFE#PBF 功能描述:IC AMP XDSL LINE DRIVER 20TSSOP RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器,接收器,收发器 系列:- 标准包装:27 系列:- 类型:收发器 驱动器/接收器数:3/3 规程:RS232,RS485 电源电压:4.75 V ~ 5.25 V 安装类型:表面贴装 封装/外壳:28-SOIC(0.295",7.50mm 宽) 供应商设备封装:28-SOIC 包装:管件
LT1794CFE#TR 功能描述:IC OPAMP 200MHZ DUAL 20-TSSOP RoHS:否 类别:集成电路 (IC) >> 接口 - 驱动器,接收器,收发器 系列:- 标准包装:27 系列:- 类型:收发器 驱动器/接收器数:3/3 规程:RS232,RS485 电源电压:4.75 V ~ 5.25 V 安装类型:表面贴装 封装/外壳:28-SOIC(0.295",7.50mm 宽) 供应商设备封装:28-SOIC 包装:管件
LT1794CFE#TRPBF 功能描述:IC AMP XDSL LINE DRIVER 20TSSOP RoHS:是 类别:集成电路 (IC) >> 接口 - 驱动器,接收器,收发器 系列:- 标准包装:27 系列:- 类型:收发器 驱动器/接收器数:3/3 规程:RS232,RS485 电源电压:4.75 V ~ 5.25 V 安装类型:表面贴装 封装/外壳:28-SOIC(0.295",7.50mm 宽) 供应商设备封装:28-SOIC 包装:管件
LT1794CSW 功能描述:IC OPAMP 200MHZ DUAL 20-SOIC RoHS:否 类别:集成电路 (IC) >> 接口 - 驱动器,接收器,收发器 系列:- 标准包装:27 系列:- 类型:收发器 驱动器/接收器数:3/3 规程:RS232,RS485 电源电压:4.75 V ~ 5.25 V 安装类型:表面贴装 封装/外壳:28-SOIC(0.295",7.50mm 宽) 供应商设备封装:28-SOIC 包装:管件