- 您現在的位置：買賣IC網 > PDF目錄385273 > DS276 (DALLAS SEMICONDUCTOR) Low Power Transceiver Chip(低功率的RS232收發(fā)器芯片) PDF資料下載
參數資料
| 型號： | DS276 |
| 廠商： | DALLAS SEMICONDUCTOR |
| 元件分類： | 通用總線功能 |
| 英文描述： | Low Power Transceiver Chip(低功率的RS232收發(fā)器芯片) |
| 中文描述： | LINE TRANSCEIVER, PDIP8 |
| 封裝： | 0.300 INCH, DIP-8 |
| 文件頁數： | 3/11頁 |
| 文件大?。?/td> | 89K |
| 代理商： | DS276 |
DS276
021998 3/11
DS276 BLOCK DIAGRAM
Figure 1
V
DRV+
V
CC
TX
IN
V
DRV–
RX
OUT
GND
TX
OUT
RX
IN
APPLICATIONS INFORMATION
The DS276 is designed as a low–cost, RS–232–E inter-
face expressly tailored for the unique requirements of
battery–operated handheld products. As shown in the
electrical specifications, the DS276 draws exceptionally
low operating and static current. During normal opera-
tion when data from the handheld system is sent from
the TX
OUT
output, the DS276 only draws significant
V
DRV+
current when TX
OUT
transitions positively (spac-
ing). This current flows primarily into the RS–232
receiver’s 3–7K
load at the other end of the attaching
cable. When TX
OUT
is marking (a negative data signal),
the V
DRV+
current falls dramatically since the negative
voltage is provided by the transmit signal from the other
end of the cable. This represents a large reduction in
overall operating current, since typical RS–232 inter-
face chips use charge–pump circuits to establish both
positive and negative levels at the transmit driver out-
put. To obtain the lowest power consumption from the
DS276, observe the following guidelines: First, to mini-
mize V
DRV+
current when connected to an RS–232 port,
always maintain TX
IN
at a logic 1 when data is not being
transmitted (idle state). This will force TX
OUT
into the
marking state, minimizing V
DRV+
current. Second,
V
DRV+
current will drop significantly when V
CC
is
grounded. Therefore, if V
DRV+
is derived independently
from V
CC
(for example connected to a 9V battery), the
logic supply voltage can be turned off to achieve the low-
est possible power state.
FULL–DUPLEX OPERATION
The DS276 is intended for full–duplex operation using
the full–duplex circuit shown in Figure 4 to generate a
negative rail from RX
IN
. The 22
μ
F capacitor forms a
negative–charge reservoir;
consequently, when the
TXD line RX
IN
is spacing (positive), TX
OUT
still has a
negative source available for a time period determined
by the capacitor and the load resistance at the other end
(3–7K
).
SUPPLY VOLTAGE OPTIONS
The DS276 is intended primarily for use in single supply
3– or 5– volts systems. However several supply config-
urations are possible.
3V OPERATION
The simplest configuration is to use a single 3V supply
for V
CC
and V
drv+
, and connect V
drv–
to ground. This will
result in the lowest power consumption and will give
adequate serial communication between two similar
devices over short distances, and into larger loads than
the 3K
RS–232 standard (Figure 2).
If V
drv+
is increased to 5V, and V
drv–
decreased (to less
than –2V) communication with standard RS–232
devices is possible, although of course the output volt-
age swing of the DS276 remains below the RS–232
specification. The V
drv–
supply can be derived using the
“stealing” technique shown in Figure 4.
5V OPERATION
The use of a single 5V supply for V
CC
and V
drv+
, and
V
drv–
derived using the circuit in Figure 4 can produce
reliable communication with standard RS–232 devices,
although the DS276 output voltage swings are below
the RS–232 minimum (Figure 3).
Increasing the magnitude of the voltage to V
drv+
to 10
volts or more will result in “true” RS–232 output voltage
levels.
相關PDF資料 |
PDF描述 |
|---|---|
| DS2782 | Stand-Alone Fuel Gauge IC |
| DS3234 | Extremely Accurate SPI Bus RTC with Integrated Crystal and SRAM |
| DS3234S | Extremely Accurate SPI Bus RTC with Integrated Crystal and SRAM |
| DS3234SN | Extremely Accurate SPI Bus RTC with Integrated Crystal and SRAM |
| DS33Z11 | Ethernet Mapper |
相關代理商/技術參數 |
參數描述 |
|---|---|
| DS276+ | 功能描述:RS-232接口集成電路 RoHS:否 制造商:Exar 數據速率:52 Mbps 工作電源電壓:5 V 電源電流:300 mA 工作溫度范圍:- 40 C to + 85 C 安裝風格:SMD/SMT 封裝 / 箱體:LQFP-100 封裝: |
| DS2760 | 制造商:DALLAS 制造商全稱:Dallas Semiconductor 功能描述:High Precision Li-Ion Battery Monitor |
| DS2760AE | 功能描述:IC BATT MON LI-ION HP 16-TSSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標準包裝:1 系列:- 功能:充電管理 電池化學:鋰離子（Li-Ion）、鋰聚合物（Li-Pol） 電源電壓:3.75 V ~ 6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應商設備封裝:SOT-23-5 包裝:剪切帶 (CT) 產品目錄頁面:669 (CN2011-ZH PDF) 其它名稱:MCP73831T-2ACI/OTCT |
| DS2760AE/T&R | 制造商:Maxim Integrated Products 功能描述:IC BATT MON LI-ION HP 16-TSSOP |
| DS2760AE/T&R | 功能描述:IC BATT MON LI-ION HP 16-TSSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 電池管理 系列:- 標準包裝:1 系列:- 功能:充電管理 電池化學:鋰離子（Li-Ion）、鋰聚合物（Li-Pol） 電源電壓:3.75 V ~ 6 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SC-74A，SOT-753 供應商設備封裝:SOT-23-5 包裝:剪切帶 (CT) 產品目錄頁面:669 (CN2011-ZH PDF) 其它名稱:MCP73831T-2ACI/OTCT |
發(fā)布緊急采購，3分鐘左右您將得到回復。