参数资料
| 型号： | SP334ET-L |
| 厂商： | Exar Corporation |
| 文件页数： | 12/13页 |
| 文件大小： | 0K |
| 描述： | IC TXRX RS232/485 PROG 28WSOIC |
| 标准包装： | 27 |
| 类型： | 收发器 |
| 驱动器/接收器数： | 3/5 |
| 规程： | RS232，RS485 |
| 电源电压： | 5V |
| 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 W |
| 包装： | 管件 |
| 其它名称： | 1016-1136-5 |
8
Exar Corporation 48720 Kato Road, Fremont CA, 94538 50-668-707 www.exar.com
SP334_00_090909
+5V
GND
TTL/CMOS
0V
0.1F
VCC
V+
V-
0V
RXEN
TTL/CMOS
T1
T2
T3
TX1
TX2
TX3
TI1
TI2
TI3
RI1
RI2
RI3
RI4
RX1
RX2
RX3
RX4
1
7
5
6
8
10
C1+
C1-
C2+
C2-
9
11
12
13
14
15
16
17
18
19
20
21
22
RS232/RS485
25
26
27
28
R1
R2
R3
R4
5K
Vcc
RS-232
0V
SP334
0.1F
400K
5K
TTL/CMOS
0.1F
C1+
C1-
C2+
C2-
2
+5V
VCC
5
GND
8
9
11
12
13
19
26
27
1
TTL/CMOS
T1
T3
R1
RS-485
V+
V-
+5V
RS232/ RS485
RS-485
4
6
7
10
14
16
15
25
3
RI2
RI1
TX3
TX4
TX1
TX2
TI1
TI3
RX1
TTL/CMOS
21
R3
17
18
RI4
RI3
RX3
RXEN
15K
400K
Vcc
400K
Vcc
RS-485
SP334
15K
0.1F
TXEN
TTL/CMOS
3
2
4
N/C
R5
5K
RI5 24
RS-232
RX5
23
TTL/CMOS
RS-232 MODE
RS-485 MDDE
Figure 2. Typical Operating Circuit
THEORY OF OPERATION
The
SP334 is made up of four separate
circuit blocks — the charge pump, drivers,
receivers, and decoder. Each of these circuit
blocks is described in more detail below.
Charge–Pump
Thechargepumpisa
Exar–patenteddesign
(U.S.5,306,954)andusesauniqueapproach
compared to older less efficient designs.
The charge pump still requires four external
capacitors, but uses a four–phase voltage
shifting technique to attain symmetrical 0V
power supplies. Figure 7(a) shows the
waveform found on the positive side of
capacitor C2, and Figure 7(b) shows the
negative side of capacitor C2. There is a
free–running oscillator that controls the four
phases of the voltage shifting. A description
of each phase follows.
Phase 1
— V
SS charge storage —During this phase of
theclockcycle,thepositivesideofcapacitors
C
and C2 are initially charged to +5V. C
+
is
then switched to ground and charge on
C
–
is transferred to C
2
–
. Since C
2
+
is con-
nected to +5V, the voltage potential across
capacitor C
2 is now 0V.
Phase 2
— V
SS transfer — Phase two of the clock con-
nects the negative terminal of C
2 to the VSS
storage capacitor and the positive terminal
of C
2 to ground, and transfers the generated
–l0V to C
3. Simultaneously, the positive side
of capacitor C
is switched to +5V and the
negative side is connected to ground.
Phase 3
— V
DD charge storage — The third phase
of the clock is identical to the first phase
— the charge transferred in C
produces
–5V in the negative terminal of C
, which
is applied to the negative side of capacitor
C
2. Since C2
+
is at +5V, the voltage potential
across C
2 is l0V.
Phase 4
— V
DD transfer — The fourth phase of the
clock connects the negative terminal of C
2
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| SP334ET-L/TR | 功能描述:RS-232接口集成电路 Programmable RS232/ RS485 Transceiver RoHS:否 制造商:Exar 数据速率:52 Mbps 工作电源电压:5 V 电源电流:300 mA 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体:LQFP-100 封装: |
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| SP3-3501 | 功能描述:CONN 3.5MM MALE STEREO PWR PLUG RoHS:是 类别:连接器，互连式 >> 套管 - 音频 系列:- 标准包装:1 系列:SealTite® 连接器类型:唱机（RCA）插座 类型:公头 信号线路:单声道 插头/配接插头直径:3.20mm 内径，9.00mm 外径（RCA） 位置/触点数:2 导线，2 触点 内部开关:不包括开关 安装类型:自由悬挂 端子:压缩 屏蔽:无屏蔽 特点:- 色彩 - 触头:金 触点材料:- 触点材料 - 镀层:- 体座材料:- 体座颜色:银 工作温度:- 电压 - 额定:- 额定电流:- 包装:散装 |
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| SP335ECR1-L | 功能描述:1/1, 2/2 Transceiver Full RS232, RS422, RS485 32-QFN (5x5) 制造商:exar corporation 系列:- 包装:散装 零件状态:有效 类型:收发器 协议:RS232，RS422，RS485 驱动器/接收器数:1/1，2/2 双工:全 接收器滞后:25mV 数据速率:1Mbps，20Mbps 电压 - 电源:3 V ~ 5.5 V 工作温度:0°C ~ 70°C 安装类型:表面贴装 封装/外壳:32-VFQFN 裸露焊盘 供应商器件封装:32-QFN（5x5） 标准包装:490 |
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