- 您现在的位置：买卖IC网 > PDF目录19895 > LTC4304CDD#TRPBF (Linear Technology)IC BUS BUFFER I2C 10-DFN PDF资料下载
参数资料
| 型号： | LTC4304CDD#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 9/16页 |
| 文件大小： | 644K |
| 描述： | IC BUS BUFFER I2C 10-DFN |
| 产品培训模块： | LTC4310 - Hot-Swappable I²C Isolators |
| 标准包装： | 2,500 |
| 类型： | 热交换开关 |
| 应用： | 通用型缓冲器/总线扩展器 |
| 内部开关： | 是 |
| 电源电压： | 2.7 V ~ 5.5 V |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-WFDFN 裸露焊盘 |
| 供应商设备封装： | 10-DFN（3x3） |
| 包装： | 带卷 (TR) |
LTC4304
9
4304fa
A rising edge on ENABLE after a stuck bus condition has
occurred forces a connection between SDAIN, SDAOUT
and SCLIN, SCLOUT even if bus idle conditions are not
met. At this time the internal 30ms timer is reset but not
disabled.
Rise Time Accelerators
Once connection has been established, rise time accel-
erator circuits on all four SDA and SCL pins are activated
(assuming accelerators are enabled, see ACC pin descrip-
tion). These allow the use of a large pull-up resistor to
reduce power consumption, or bus capacitance beyond
that speci ed in I
2
C, while still meeting system rise time
requirements. During positive bus transitions, the LTC4304
switches in 3.5mA (typical) of current to quickly slew the
SDA and SCL lines once their DC voltages exceed 0.8V.
Choose a pull-up resistor so that the bus will rise on its
own at a rate of at least 0.8V/祍 to guarantee activation
of the accelerators. Rise time accelerators turn off when
SDA and SCL lines are approximately 1V below V
CC
.
Rise time accelerators are automatically disabled during
automatic clocking.
Resistor Pull-Up Selection
The system pull-up resistors must be strong enough
to provide a positive slew rate of 0.8V/祍 on the SDA
and SCL pins, in order to activate the rise time accelera-
tors during rising edges. Choose maximum resistor value
R
PULL-UP(MAX)
using the formula:
R
k
V
V
ns V
C
pF
PULLUP MAX
BUS MIN
BUS
(
)
( )
[ ]
.
"
[ / ]
[ ]
& =
(
)
0 8
1250
where V
BUSMIN
is the minimum operating pull-up sup-
ply voltage, and C
BUS
the total capacitance on respec-
tive bus line.
For example, assume V
BUS
= V
CC
= 3.3V, and assuming
?0% supply tolerance, V
BUSMIN
= 2.97V. With C
BUS
=
100pF, R
PULL-UP, MAX
= 27.1k. Therefore a smaller pull-up
resistor than 27.1k must be used, so 10k works ne.
Live Insertion and Capacitance Buffering Application
Figures 3 through 6 illustrate applications of the LTC4304
that take advantage of both its Hot Swap
TM
controlling and
capacitance buffering features. In all of these applications,
note that if the I/O cards were plugged directly into the
backplane without the LTC4304 buffer, all of the backplane
and card capacitances would add directly together, making
rise- and fall-time requirements dif cult to meet. Placing a
LTC4304 on the edge of each card, however, isolates the
card capacitance from the backplane. For a given I/O card,
the LTC4304 drives the capacitance on the card side and
the backplane must drive only the digital input capacitance
of the LTC4304, which is less than 10pF.
In most applications the LTC4304 will be used with a
staggered connector where V
CC
and GND will be long
pins. SDA and SCL are medium length pins to ensure that
the V
CC
and GND pins make contact rst. This will allow
the precharge circuitry to be activated on SDA and SCL
before they make contact. ENABLE is a short pin that is
pulled down when not connected. This is to ensure that the
connection between the backplane and the cards data and
clock busses is not enabled until the transients associated
with live insertion have settled.
Figure 3 shows the LTC4304 in a CompactPCI
TM
con gura-
tion. Connect V
CC
and ENABLE to the output of one of the
CompactPCI power supply Hot Swap circuits. Use a pull-up
resistor to ENABLE for a card side enable/disable. V
CC
is
monitored by a ltered UVLO circuit. With the V
CC
voltage
powering up after all the other pins have established con-
nection, the UVLO circuit ensures that the backplane and
the card data and clock busses are not connected until
the transients associated with live insertion have settled.
Owing to their small capacitance, the SDAIN and SCLIN
pins cause minimal disturbance on the backplane busses
when they make contact with the connector.
Hot Swap is a trademark of Linear Technology Corporation.
OPERATION
APPLICATIONS INFORMATION
相关PDF资料 |
PDF描述 |
|---|---|
| TOP224GN-TL | IC OFFLINE SWIT PWM OCP HV 8SMD |
| EYM10DTBN-S189 | CONN EDGECARD 20POS R/A .156 SLD |
| ESA50DRSN-S288 | CONN EDGECARD 100POS .125 EXTEND |
| VE-21W-CY-F4 | CONVERTER MOD DC/DC 5.5V 50W |
| LTC4301LIMS8#PBF | IC BUFFER BUS HOTSWAP 2WR 8MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC4304CMS | 制造商:Linear Technology 功能描述:MS-Bus Buffers, I2C Bus Buffer with Stuck Bus Recovery |
| LTC4304CMS#PBF | 功能描述:IC BUS BUFFER I2C 10-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:119 系列:- 类型:热交换控制器 应用:通用型，PCI Express? 内部开关:无 电流限制:- 电源电压:3.3V，12V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:80-TQFP 供应商设备封装:80-TQFP（12x12） 包装:托盘 产品目录页面:1423 (CN2011-ZH PDF) |
| LTC4304CMS#TRPBF | 功能描述:IC BUS BUFFER I2C 10-MSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 标准包装:50 系列:- 类型:热交换控制器 应用:-48V 远程电力系统，AdvancedTCA ? 系统，高可用性 内部开关:无 电流限制:可调 电源电压:11.5 V ~ 14.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:10-TFSOP，10-MSOP（0.118"，3.00mm 宽） 供应商设备封装:10-MSOP 包装:管件 |
| LTC4304IDD | 制造商:Linear Technology 功能描述:Hot Swappable Bus Buffer 10-Pin DFN EP |
| LTC4304IDD#PBF | 功能描述:IC BUS BUFFER I2C 10-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:100 系列:- 类型:热插拔开关 应用:通用 内部开关:是 电流限制:可调 电源电压:9 V ~ 13.2 V 工作温度:-40°C ~ 150°C 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-TDFN-EP（3x3） 包装:管件 |
发布紧急采购，3分钟左右您将得到回复。