- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄377779 > LTC485CN8 (LINEAR TECHNOLOGY CORP) Low Power RS485 Interface Transceiver PDF資料下載
參數(shù)資料
| 型號： | LTC485CN8 |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 通用總線功能 |
| 英文描述： | Low Power RS485 Interface Transceiver |
| 中文描述： | LINE TRANSCEIVER, PDIP8 |
| 封裝： | 0.300 INCH, PLASTIC, DIP-8 |
| 文件頁數(shù)： | 7/12頁 |
| 文件大?。?/td> | 327K |
| 代理商： | LTC485CN8 |
7
LTC485
APPLICATIU
Basic Theory of Operation
Previous RS485 transceivers have been designed using
bipolar technology because the common-mode range of
the device must extend beyond the supplies and the device
must be immune to ESD damage and latchup. Unfortu-
nately, the bipolar devices draw a large amount of supply
current, which is unacceptable for the numerous applica-
tions that require low power consumption. The LTC485 is
the first CMOS RS485/RS422 transceiver which features
ultra-low power consumption without sacrificing ESD and
latchup immunity.
The LTC485 uses a proprietary driver output stage, which
allows a common-mode range that extends beyond the
power supplies while virtually eliminating latchup and
providing excellent ESD protection. Figure 9 shows the
LTC485 output stage while Figure 10 shows a conven-
tional CMOS output stage.
When the conventional CMOS output stage of Figure 10
enters a high impedance state, both the P-channel (P1)
and the N-channel (N1) are turned off. If the output is then
driven above V
CC
or below ground, the P + /N-well diode
U
W
U
(D1) or the N + /P-substrate diode (D2) respectively will
turn on and clamp the output to the supply. Thus, the
output stage is no longer in a high impedance state and is
not able to meet the RS485 common-mode range require-
ment. In addition, the large amount of current flowing
through either diode will induce the well known CMOS
latchup condition, which could destroy the device.
The LTC485 output stage of Figure 9 eliminates these
problems by adding two Schottky diodes, SD3 and SD4.
The Schottky diodes are fabricated by a proprietary modi-
fication to the standard N-well CMOS process. When the
output stage is operating normally, the Schottky diodes
are forward biased and have a small voltage drop across
them. When the output is in the high impedance state and
is driven above V
CC
or below ground, the parasitic diodes
D1 or D2 still turn on, but SD3 or SD4 will reverse bias and
prevent current from flowing into the N-well or the sub-
strate. Thus, the high impedance state is maintained even
with the output voltage beyond the supplies. With no
minority carrier current flowing into the N-well or sub-
strate, latchup is virtually eliminated under power-up or
power-down conditions.
LOGIC
V
CC
SD3
P1
D1
OUTPUT
SD4
D2
N1
LTC485 F09
LOGIC
V
CC
P1
D1
OUTPUT
D2
N1
LTC485 F10
Figure 9. LTC485 Output Stage
Figure 10. Conventional CMOS Output Stage
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC485CS8 | Low Power RS485 Interface Transceiver |
| LTC485I | Low Power RS485 Interface Transceiver |
| LTC485IS8 | Low Power RS485 Interface Transceiver |
| LTC485M | Low Power RS485 Interface Transceiver |
| LTC485MJ8 | Low Power RS485 Interface Transceiver |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC485CN8#PBF | 功能描述:IC TXRX INTRFC RS485 LOPWR 8-DIP RoHS:是 類別:集成電路 (IC) >> 接口 - 驅(qū)動(dòng)器，接收器，收發(fā)器 系列:- 標(biāo)準(zhǔn)包裝:98 系列:* |
| LTC485CN8PBF | 制造商:Linear Technology 功能描述:LTC485CN8PBF |
| LTC485CS8 | 功能描述:IC TXRX INTRFC RS485 LOPWR 8SOIC RoHS:否 類別:集成電路 (IC) >> 接口 - 驅(qū)動(dòng)器，接收器，收發(fā)器 系列:- 標(biāo)準(zhǔn)包裝:121 系列:- 類型:收發(fā)器 驅(qū)動(dòng)器/接收器數(shù):1/1 規(guī)程:RS422，RS485 電源電壓:3 V ~ 3.6 V 安裝類型:表面貼裝 封裝/外殼:10-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:10-DFN（3x3） 包裝:管件 |
| LTC485CS8#PBF | 功能描述:IC TXRX INTRFC RS485 LOPWR 8SOIC RoHS:是 類別:集成電路 (IC) >> 接口 - 驅(qū)動(dòng)器，接收器，收發(fā)器 系列:- 產(chǎn)品培訓(xùn)模塊:RS-232 & USB Transceiver 標(biāo)準(zhǔn)包裝:2,000 系列:- 類型:收發(fā)器 驅(qū)動(dòng)器/接收器數(shù):1/1 規(guī)程:RS232 電源電壓:3 V ~ 5.5 V 安裝類型:表面貼裝 封裝/外殼:16-SSOP（0.209"，5.30mm 寬） 供應(yīng)商設(shè)備封裝:16-SSOP 包裝:帶卷 (TR) 其它名稱:296-19849-2 |
| LTC485CS8#TR | 功能描述:IC TXRX INTRFC RS485 LOPWR 8SOIC RoHS:否 類別:集成電路 (IC) >> 接口 - 驅(qū)動(dòng)器，接收器，收發(fā)器 系列:- 標(biāo)準(zhǔn)包裝:121 系列:- 類型:收發(fā)器 驅(qū)動(dòng)器/接收器數(shù):1/1 規(guī)程:RS422，RS485 電源電壓:3 V ~ 3.6 V 安裝類型:表面貼裝 封裝/外殼:10-WFDFN 裸露焊盤 供應(yīng)商設(shè)備封裝:10-DFN（3x3） 包裝:管件 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。