參數資料
型號: ICL3217EIB
廠商: Intersil
文件頁數: 10/12頁
文件大小: 0K
描述: IC TXRX RS-232 3-5.5V ESD 24SOIC
標準包裝: 30
類型: 收發(fā)器
驅動器/接收器數: 5/3
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: 24-SOIC(0.295",7.50mm 寬)
供應商設備封裝: 24-SOIC
包裝: 管件
7
This automatic powerdown feature provides additional
system power savings without changes to the existing
operating system or hardware.
Utilizing power management circuitry, to power down the
rest of the communication circuitry (e.g., the UART) when
the ICL3217E powers down, produces even greater power
savings. Connecting a transition detector to the V- pin (see
Figure 3) is an easy way for the power management logic to
determine when the ICL3217E enters and exits powerdown.
Capacitor Selection
The charge pumps require 0.1
F, or greater, capacitors for
3.3V operation. With 0.1
F capacitors, five percent tolerance
supplies (e.g., 3.14V minimum) deliver greater than
±5V
transmitter swings at full data rate, while ten percent
tolerance supplies (e.g., 2.97V minimum) deliver
±4.95V
transmitter swings. If greater than
±5V transmitter swings
are required with a 10% tolerance 3.3V supply, 0.22
F
capacitors are recommended (see Table 3). Existing 5V
applications typically utilize either 0.1
F or 1F capacitors,
and the ICL32X7E works well with either value. New 5V
designs should use 0.22
F capacitors for the best results.
For other supply voltages refer to Table 3 for capacitor
values. Do not use values smaller than those listed in
Table 3. Increasing the capacitor values (by a factor of two)
reduces ripple on the transmitter outputs and slightly
reduces power consumption. C2, C3, and C4 can be
increased without increasing C1’s value, however, do not
increase C1 without also increasing C2, C3, and C4 to
maintain the proper ratios (C1 to the other capacitors).
When using minimum required capacitor values, make sure
that capacitor values do not degrade excessively with
temperature. If in doubt, use capacitors with a larger nominal
value. The capacitor’s equivalent series resistance (ESR)
usually rises at low temperatures and it influences the
amount of ripple on V+ and V-
.
Power Supply Decoupling
In most circumstances a 0.1
F bypass capacitor is
adequate. In applications that are particularly sensitive to
power supply noise, decouple VCC to ground with a
capacitor of the same value as the charge-pump capacitor C1.
Connect the bypass capacitor as close as possible to the IC.
Transmitter Outputs when Exiting
Powerdown
Figure 6 shows the response of two ICL3217E transmitter
outputs when exiting powerdown mode. As they activate, the
two transmitter outputs properly go to opposite RS-232
levels, with no glitching, ringing, nor undesirable transients.
Each transmitter is loaded with 3k
in parallel with 2500pF.
Note that the transmitters enable only when the magnitude
of the supplies exceed approximately 3V.
.
FIGURE 4. DEFINITION OF VALID RS-232 RECEIVER
LEVELS
0.3V
-0.3V
-2.7V
2.7V
INVALID LEVEL - POWERDOWN OCCURS AFTER 30
s
VALID RS-232 LEVEL - ICL3217E IS ACTIVE
INDETERMINATE - POWERDOWN MAY OR
MAY NOT OCCUR
INDETERMINATE - POWERDOWN MAY OR
MAY NOT OCCUR
RECEIVER
INPUTS
TRANSMITTER
OUTPUTS
V+
VCC
0
V-
INVALID
REGION
}
FIGURE 5. AUTOMATIC POWERDOWN TIMING DIAGRAM
AUTOPWDN
PWR UP (tWU)
TABLE 3. REQUIRED CAPACITOR VALUES
VCC (V)
C1 (F)
C2, C3, C4 (F)
3.15 to 3.6
0.1
3.0 to 3.6
0.22
4.5 to 5.5
0.1 to 1.0
3.0 to 5.5
0.22
TIME (20
s/DIV.)
T1
T2
2V/DIV
5V/DIV
VCC = +3.3V
C1 - C4 = 0.1
F
RXIN
FIGURE 6. TRANSMITTER OUTPUTS WHEN EXITING
POWERDOWN (ICL3217E ONLY)
ICL3207E, ICL3217E
相關PDF資料
PDF描述
MS3126E14-18PZ CONN PLUG 18POS STRAIGHT W/PINS
MS3126E14-18PW CONN PLUG 18POS STRAIGHT W/PINS
MS3126E14-18P CONN PLUG 18POS STRAIGHT W/PINS
ICL3217ECB IC TXRX RS-232 3-5.5V ESD 24SOIC
HIN232ACP IC TXRX RS-232 5V HS 16-DIP
相關代理商/技術參數
參數描述
ICL3217EIB-T 功能描述:IC 5DRVR/3RCVR RS232 3V 24-SOIC RoHS:否 類別:集成電路 (IC) >> 接口 - 驅動器,接收器,收發(fā)器 系列:- 標準包裝:1,000 系列:- 類型:收發(fā)器 驅動器/接收器數:2/2 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-SOIC(0.295",7.50mm 寬) 供應商設備封裝:16-SOIC 包裝:帶卷 (TR)
ICL3217EIBZ 功能描述:RS-232接口集成電路 RS232 3V 5D/3R 15KV AUTODWN 24 IND 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:
ICL3217EIBZ-T 功能描述:RS-232接口集成電路 RS232 3V 5D/3R 15KV AUTODWN 24 INDEL 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:
ICL3217EIP 制造商:Rochester Electronics LLC 功能描述:- Bulk
ICL3217IA 功能描述:IC 5DRVR/3RCVR RS232 3V 24-SSOP RoHS:否 類別:集成電路 (IC) >> 接口 - 驅動器,接收器,收發(fā)器 系列:- 標準包裝:1,000 系列:- 類型:收發(fā)器 驅動器/接收器數:2/2 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-SOIC(0.295",7.50mm 寬) 供應商設備封裝:16-SOIC 包裝:帶卷 (TR)