參數(shù)資料
型號(hào): LTC4240CGN
廠商: LINEAR TECHNOLOGY CORP
元件分類: 電源管理
英文描述: CompactPCI Hot Swap Controller with I2C Compatible Interface
中文描述: 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO28
封裝: 0.150 INCH, PLASTIC, SSOP28
文件頁(yè)數(shù): 16/28頁(yè)
文件大?。?/td> 486K
代理商: LTC4240CGN
LTC4240
16
4240f
A high to low transition on BD_SEL# causes the voltages
on the TIMER, GATE, 3V
OUT
, 5V
OUT
, 12V
OUT
and V
EEOUT
pins to begin ramping (see Figure 4). The TIMER pin
capacitance is charged by an 11.5
μ
A current source while
the GATE capacitance is charged by a 65
μ
A current source.
Concurrently, an internal charge pump turns on the gates
of the internal power switches that isolate the 12V and
–12V supplies. All faults are ignored during the time that
the voltage at the TIMER pin remains below 5.5V. In order
to avoid faults due to the charging of the bulk output
capacitors, all output voltages must settle before the
TIMER pin reaches 5.5V. See TIMER section for more
details.
The 5V
OUT
and 3V
OUT
supply outputs will ramp up accord-
ing to the slowest of the following slew rates:
dV
dt
A
C
or
I
I
C
a
or
I
I
C
b
LIMIT
V
LOAD V
LOAD VOUT
5
(
)
LIMIT
V
LOAD V
LOAD VOUT
3
(
=
μ
1
=
=
65
1
( )
1
( )
5
5
3
3
,
,
(
)
(
)
(
)
(
)
)
stage in the hot plug sequence, indicating that the
LTC4240 is in reset mode with all power switches off
(BD_SEL# is still pulled high to long 5V).
The 12V and –12V supplies make contact at this stage.
Zener clamps Z1 and Z2 plus shunt RC snubbers R13-
C4 and R14-C5 help protect the 12V
IN
and V
EEIN
pins,
respectively, from large transient voltages during hot
insertion and short-circuit conditions.
The signal pins also connect at this point. This includes
the HEALTHY# signal connecting to the PWRGD pin
and the PCI_RST# signal connecting to the RESETIN
pin. The PWRGD and RESETIN signals are combined
internally with Bit 3 (C3) of the I
2
C command latch (see
Send Byte protocol) to generate the LOCAL_PCI_RST#
signal, which is available at the RESETOUT pin.
4. Short pins make contact. BD_SEL# signal connects to
the OFF/ON pin. This starts the electrical part of the
connection process. If the BD_SEL# signal is grounded
on the backplane, then the electrical connection pro-
cess starts immediately. Note that the electrical con-
nection process can be interrupted with the Send Byte
protocol of the I
2
C serial interface.
System backplanes that do not ground the BD_SEL#
signal will instead have circuitry that detects when
BD_SEL# has made contact with the plug-in board. The
backplane logic can then control the power up process
by pulling BD_SEL# low. Figure 4 illustrates the power
up sequence. The mating of BD_SEL# is represented by
the high to low transition of the BD_SEL# signal.
Power-Up Sequence
Two external N-channel power MOSFETs isolate the 3.3V
and 5V power paths, while two internal MOS switches
isolate the 12V and –12V power paths. (See front page
Application Circuit). Sense resistors R1 and R2 provide
current limit and fault detection for the 3V
IN
and 5V
IN
supplies, while R5 and C1 provide current control loop
compensation. Current fault detection for the 12V and
–12V supplies is done internally.
TIMER
10V/DIV
GATE
10V/DIV
12V
OUT
10V/DIV
5V
OUT
10V/DIV
3V
10V/DIV
V
10V/DIV
BD_SEL#
5V/DIV
LCL_PCI_RST#
5V/DIV
HEALTHY#
5V/DIV
10ms/DIV
4240 F04
Figure 4. Normal Power-Up Sequence
APPLICATIU
W
U
U
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PDF描述
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC4240CGN#PBF 功能描述:IC CTLR HOT SWAP CPCI I2C 28SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:119 系列:- 類型:熱交換控制器 應(yīng)用:通用型,PCI Express? 內(nèi)部開關(guān):無(wú) 電流限制:- 電源電壓:3.3V,12V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:80-TQFP 供應(yīng)商設(shè)備封裝:80-TQFP(12x12) 包裝:托盤 產(chǎn)品目錄頁(yè)面:1423 (CN2011-ZH PDF)
LTC4240CGN#TR 功能描述:IC CTRLR HOT SWAP CPCI 28-SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:119 系列:- 類型:熱交換控制器 應(yīng)用:通用型,PCI Express? 內(nèi)部開關(guān):無(wú) 電流限制:- 電源電壓:3.3V,12V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:80-TQFP 供應(yīng)商設(shè)備封裝:80-TQFP(12x12) 包裝:托盤 產(chǎn)品目錄頁(yè)面:1423 (CN2011-ZH PDF)
LTC4240CGN#TRPBF 功能描述:IC CTRLR HOTSWAP CPCI I2C 28SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:119 系列:- 類型:熱交換控制器 應(yīng)用:通用型,PCI Express? 內(nèi)部開關(guān):無(wú) 電流限制:- 電源電壓:3.3V,12V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:80-TQFP 供應(yīng)商設(shè)備封裝:80-TQFP(12x12) 包裝:托盤 產(chǎn)品目錄頁(yè)面:1423 (CN2011-ZH PDF)
LTC4240IGN 功能描述:IC CTRLR HOT SWAP CPCI 28-SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:119 系列:- 類型:熱交換控制器 應(yīng)用:通用型,PCI Express? 內(nèi)部開關(guān):無(wú) 電流限制:- 電源電壓:3.3V,12V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:80-TQFP 供應(yīng)商設(shè)備封裝:80-TQFP(12x12) 包裝:托盤 產(chǎn)品目錄頁(yè)面:1423 (CN2011-ZH PDF)
LTC4240IGN#PBF 功能描述:IC CTRLR HOTSWAP CPCI I2C 28SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 熱交換 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:119 系列:- 類型:熱交換控制器 應(yīng)用:通用型,PCI Express? 內(nèi)部開關(guān):無(wú) 電流限制:- 電源電壓:3.3V,12V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:80-TQFP 供應(yīng)商設(shè)備封裝:80-TQFP(12x12) 包裝:托盤 產(chǎn)品目錄頁(yè)面:1423 (CN2011-ZH PDF)