参数资料
型号: LTC1544CG
厂商: Linear Technology
文件页数: 5/20页
文件大小: 0K
描述: IC TXRX SOFTWARE SELECTBL 28SSOP
标准包装: 47
类型: 收发器
驱动器/接收器数: 4/4
电源电压: 4.75 V ~ 5.25 V
安装类型: 表面贴装
封装/外壳: 28-SSOP(0.209",5.30mm 宽)
供应商设备封装: 28-SSOP
包装: 管件
13
LTC1544
Charge Pump
The LTC1543 uses an internal capacitive charge pump to
generate VDD and VEE as shown in Figure 21. A voltage
doubler generates about 8V on VDD and a voltage inverter
generates about – 7.5V for VEE. Four 1F surface mounted
tantalum or ceramic capacitors are required for C1, C2, C3
and C4. The VEE capacitor C5 should be a minimum of
3.3
F.Allcapacitorsare16Vandshouldbeplacedasclose
as possible to the LTC1543 to reduce EMI.
The generator differential impedance must be 50
to
150
and the impedance between shorted terminals (A
and B) and ground C must be 150
±15. For the
generator termination, switches S1 and S2 are both on and
the top side of the center resistor is brought out to a pin so
it can be bypassed with an external capacitor to reduce
common mode noise as shown in Figure 20.
Figure 20. V.35 Driver Using the LTC1344A
V.35 DRIVER
A
B
C
51.5
S2
ON
S1
ON
1544 F20
51.5
LTC1344A
124
C1
100pF
28
27
26
25
1544 F21
3
2
1
4
C3
1
F
C4
1
F
5V
C1
1
F
C2
1
F
C5
3.3
F
LTC1543
VDD
C1+
C1
VCC
C2+
C2
VEE
GND
+
Figure 21. Charge Pump
Any mismatch in the driver rise and fall times or skew in
the driver propagation delays will force current through
the center termination resistor to ground, causing a high
frequency common mode spike on the A and B terminals.
The common mode spike can cause EMI problems that are
reduced by capacitor C1 which shunts much of the com-
mon mode energy to ground rather than down the cable.
No-Cable Mode
The no-cable mode (M0 = M1 = M2 = 1) is intended for the
case when the cable is disconnected from the connector.
The charge pump, bias circuitry, drivers and receivers are
turned off, the driver outputs are forced into a high
impedance state, and the supply current drops to less than
200
A.
Receiver Fail-Safe
All LTC1543/LTC1544 receivers feature fail-safe opera-
tion in all modes. If the receiver inputs are left floating or
shorted together by a termination resistor, the receiver
output will always be forced to a logic high.
DTE vs DCE Operation
The DCE/DTE pin acts as an enable for Driver 3/Receiver
1 in the LTC1543, and Driver 3/Receiver 1 and Driver 4/
Receiver 4 in the LTC1544. The INVERT pin in the LTC1544
allows the Driver 4/Receiver 4 enable to be high or low true
polarity.
APPLICATIONS INFORMATION
WU
U
相关PDF资料
PDF描述
IDT72V3612L12PF8 IC FIFO 64X36X2 12NS 120QFP
VE-B1V-MY CONVERTER MOD DC/DC 5.8V 50W
LT1131ACSW IC 5DRV/4RCV RS232 5V 28-SOIC
AD1376JD IC ADC SNGL 16BIT 32DIP
LT1132ACSW IC 5DRV/3RCV RS232 5V 24-SOIC
相关代理商/技术参数
参数描述
LTC1544CG#PBF 功能描述:IC TXRX SOFTWARE SELECTBL 28SSOP 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:1 系列:- 类型:线路收发器 驱动器/接收器数:5/3 规程:RS232 电源电压:3 V ~ 5.5 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:Digi-Reel® 产品目录页面:918 (CN2011-ZH PDF) 其它名称:296-25096-6
LTC1544CG#TR 功能描述:IC TXRX SFTWR SEL DTE/DCE 28SSOP 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
LTC1544CG#TRPBF 功能描述:IC TXRX SOFTWARE SELECTBL 28SSOP 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
LTC1544IG 功能描述:IC TXRX SFTWR SEL DTE/DCE 28SSOP 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:250 系列:- 类型:收发器 驱动器/接收器数:2/2 规程:RS232 电源电压:3 V ~ 5.5 V 安装类型:表面贴装 封装/外壳:16-TSSOP(0.173",4.40mm 宽) 供应商设备封装:16-TSSOP 包装:带卷 (TR)
LTC1544IG#PBF 功能描述:IC TXRX SOFTWARE SELECTBL 28SSOP 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:250 系列:- 类型:收发器 驱动器/接收器数:2/2 规程:RS232 电源电压:3 V ~ 5.5 V 安装类型:表面贴装 封装/外壳:16-TSSOP(0.173",4.40mm 宽) 供应商设备封装:16-TSSOP 包装:带卷 (TR)