- 您现在的位置：买卖IC网 > PDF目录19716 > LTC4245IG#TRPBF (Linear Technology)IC CNTRLR HOT SWAP 36-SSOP PDF资料下载
参数资料
| 型号： | LTC4245IG#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 26/36页 |
| 文件大小： | 431K |
| 描述： | IC CNTRLR HOT SWAP 36-SSOP |
| 标准包装： | 1,000 |
| 类型： | 热交换控制器 |
| 应用： | CompactPCI? |
| 内部开关： | 无 |
| 电源电压： | 3.3V，5V，12V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 36-SSOP（0.209"，5.30mm 宽） |
| 供应商设备封装： | 36-SSOP |
| 包装： | 带卷 (TR) |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页当前第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页
LTC4245
26
4245fa
Table 2. Sense Resistance Values
SUPPLY
R
SENSE
(1%)
I
TRIP(MIN)
I
TRIP(MAX)
12V
50m?/DIV>
891mA
1.1A
5V
3.5m?/DIV>
6.4A
7.9A
3.3V
2.5m?/DIV>
8.9A
11.1A
12V
100m?/DIV>
396mA
606mA
If necessary, two resistors with the same tolerance can
be connected in parallel to yield the 3.5m?and 2.5m?
values.
2. Select the SS capacitor for limiting the rate of rise of
inrush current. Equations 1 and 2 lead to the following
design equation:
C
G I
R
dI dt
SS MIN
SS SS MAX
SENSE MIN
MA
( )
( )
( )
(
"
"( / )
e
XX)
(6)
Applying Equation 6 to the 12V supply, with G
SS
of 46mV/V,
I
SS(MAX)
of 24糀, R
SENSE(MIN)
of 49.5m? and (dI/dt)
(MAX)
of 150mA/ms yields a C
SS(MIN)
greater than 149nF. This
capacitance value satis es the dI/dt requirements of the
other supplies too. Hence, a 220nF (?0%) capacitor is
chosen for C
SS
.
3. To determine the TIMER capacitance, the time required
to completely power-up all supply outputs simultaneously
needs to be calculated. There are three parts to this time:
time for the internal current limit to cross zero (t
1
), time
for the gate to slew to the MOSFET threshold voltage (t
2
)
and the time for the current ow to charge up the load
capacitors (t
3
) (see Figure 17).
t
1
: The time for the internal current limit to rise above
zero is simply:
t
I
dI dt
FBL MIN
MIN
1
4
= "
( / )
( )
( )
(7)
t
2
: The maximum time for the gate of the external MOSFET to
rise to the threshold voltage depends on I
GATE(UP)(MIN)
and
the gate charge required to turn on the external MOSFET.
A typical value for this time is 1ms. This can be veri ed
after the MOSFETs are selected. Since the current limit
ramp is almost stopped while any MOSFET is turning on,
t
2
is 4 times 1ms or 4ms, since in the worst case none of
the four MOSFET turn-ons overlaps in time.
t
3
: Under simultaneous power-up each output voltage af-
fects the inrush current pro le. To simplify calculations, the
inrush current pro le shown in Figure 17 is chosen. All the
current is assumed to charge the load capacitor, i.e., there
is no load current. There are four parts to t
3
as shown.
Equations 8 to 11 are used to determine t
31
to t
34
:
t
I
dI dt
FBL MIN
MIN
31
=
( )
( )
( / )
(8)
t
C V
I
t
L FB
FBL MIN
32
31
0 5
=
"
. "
( )
(9)
t
I
I
dI dt
C
FBH MIN FBL MIN
MIN
L
33
2
=min
( / )
,
"
( )
( )
( )
""(
)
( / )
( )
V
V
dI dt
t
t
OUT FB
MIN
+
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
2
31
31
煙
?/DIV>
?/DIV>
?/DIV>
(10)
t
C V
V
t
I
I
L
OUT FB
FBL MIN
34
33
0
0 5
=
+
max
,
"(
) . "
"(
( )
FFBH MIN
FBH MIN
I
( )
( )
)
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
?/DIV>
(11)
APPLICATIO S I FOR ATIO
U
U
U
t
1
t
31
V
GATE
= 0
V
GATE
= V
TH
I
NEG
0
I
FBL
I
FBH
V
OUT
= V
FB
V
OUT
= V
IN
(SMALL C
L
)
V
OUT
= V
IN
(LARGE C
L
)
t
32
t
33
t
33
t
34
OR
t
2
4245 F17
INTERNAL CURRENT LIMIT
INRUSH CURRENT FOR LARGER C
L
INRUSH CURRENT FOR SMALLER C
L
Figure 17. Inrush Current Pro le for Design Example
相关PDF资料 |
PDF描述 |
|---|---|
| 190-009-163R001 | CONN DB9 MALE R/A SOLDER SMD |
| ESA43DRMN | CONN EDGECARD 86POS .125 SQ WW |
| ISPLSI 2128E-135LT176 | IC PLD ISP 128I/O 7.5NS 176TQFP |
| EMA43DRMN | CONN EDGECARD 86POS .125 SQ WW |
| MIC39150-2.5BT | IC REG LDO 2.5V 1.5A TO-220 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AD7606BSTZ | 制造商:Analog Devices 功能描述:IC ADC 16BIT 200KSPS QFP-64 制造商:Analog Devices 功能描述:IC, ADC, 16BIT, 200KSPS, QFP-64 |
| AD7606BSTZ-4 | 功能描述:IC DAS W/ADC 16BIT 4CH 64LQFP RoHS:是 类别:集成电路 (IC) >> 数据采集 - ADCs/DAC - 专用型 系列:- 产品培训模块:Data Converter Basics 标准包装:1 系列:- 类型:电机控制 分辨率（位）:12 b 采样率（每秒）:1M 数据接口:串行，并联 电压电源:单电源 电源电压:2.7 V ~ 3.6 V，4.5 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:100-TQFP 供应商设备封装:100-TQFP（14x14） 包装:剪切带 (CT) 其它名称:296-18373-1 |
| AD7606BSTZ-4 | 制造商:Analog Devices 功能描述:IC, ADC, 16BIT, 200KSPS, QFP-64 |
| AD7606BSTZ-4RL | 功能描述:IC DAS W/ADC 16BIT 64LQFP RoHS:是 类别:集成电路 (IC) >> 数据采集 - ADCs/DAC - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 类型:数据采集系统（DAS） 分辨率（位）:16 b 采样率（每秒）:21.94k 数据接口:MICROWIRE?，QSPI?，串行，SPI? 电压电源:模拟和数字 电源电压:1.8 V ~ 3.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP（6x6） 包装:托盘 |
| AD7606BSTZ-6 | 功能描述:IC DAS W/ADC 16BIT 6CH 64LQFP RoHS:是 类别:集成电路 (IC) >> 数据采集 - ADCs/DAC - 专用型 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:50 系列:- 类型:数据采集系统（DAS） 分辨率（位）:16 b 采样率（每秒）:21.94k 数据接口:MICROWIRE?，QSPI?，串行，SPI? 电压电源:模拟和数字 电源电压:1.8 V ~ 3.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:40-WFQFN 裸露焊盘 供应商设备封装:40-TQFN-EP（6x6） 包装:托盘 |
发布紧急采购，3分钟左右您将得到回复。