參數(shù)資料
型號: LTC1699-80
廠商: Linear Technology Corporation
英文描述: SMBus VID Voltage Programmers(SMBus 接口VID電壓編程器)
中文描述: VID電壓編程的SMBus(西元的SMBus接口電壓編程器)
文件頁數(shù): 14/20頁
文件大?。?/td> 250K
代理商: LTC1699-80
LTC1699 Series
14
pin is used to shut down the converters without the need
for lengthy SMBus Off protocols and can also be used to
turn on up to three DC/DC converters simultaneously. The
VRON pin has an internal 2.5uA current source pull-up.
The CPU_ON, IO_ON and CLK_ON pins are N-channel,
open drain outputs. These outputs can be connected to the
RUN/SS pin of LTC DC/DC converters that generate the
V
CC
supplies of the CPU, I/O circuits and the clock buffer.
The RUN/SS pin shuts down the converter if pulled low
and also serves as a connection for the soft-start capaci-
tor. The CPU_ON, IO_ON and CLK_ON pins are open drain
outputs and do not interfere with soft-start when switched
into a high impedance state. To keep the I/O and clock
buffer V
CC
supplies alive at all times, disconnect the IO_ON
and CLK_ON pins from the corresponding RUN/SS pins.
The N-channel FETs at the CPU_ON, IO_ON and CLK_ON
pins typically discharge a 0.1
μ
F (0.01
μ
F) soft-start capaci-
tor from 3V to 0.35V in 21
μ
s (2.3
μ
s) with V
CC
= 2.7V.
The PGOOD or “Power Good” pin is also an open drain,
N-channel output. The PGOOD pin pulls low if the DC/DC
converters are shutdown. If the converters are turned on,
an internal timer keeps PGOOD low for 50
μ
s (typical)
which allows time for the converters to enter regulation.
Toggling the SEL pin while the converters are turned on
also causes the PGOOD pin to pull low for 50
μ
s. The
PGOOD pin may be used to force continuous operation in
an LTC DC/DC converter. If the SEL pin is toggled to select
a lower output voltage, it may take an unacceptably long
time for the output of the DC/DC converter to decrease to
the new voltage under light load conditions. To reduce this
time needed, the PGOOD pin can be connected to the FCB
(force continuous bar) pin of the converter. When the SEL
pin is toggled to select a new code, FCB pin is forced low
for 50
μ
s. This forces the DC/DC converter out of Burst
Mode
TM
operation and into continuous mode.
The VRON pin and SMBON, the output of the internal on/
off state machine, control the state of the CPU_ON, IO_ON,
CLK_ON and PGOOD pins. The DCON signal is a logical
NAND function of the logical states of VRON and SMBON
and is the status bit that is returned during Read-back.
Table3 shows the state of the CPU_ON, IO_ON, and
CLK_ON pins for various combinations of VRON and
SMBON.
Table 3. DC/DC Converter Control Pins
VRON
SMBON
DCON
0
X
(Note 3)
1
0
1
PGOOD
0
CPU_ON, IO_ON, CLK_ON
0
1
1
0
0
0 for 50
μ
s
(Note 1)
0 for 50
μ
s
(Note 1)
Z (Note 2)
1
Z (Note 2)
Note 1:
Also triggered by SEL pin toggling.
Note 2:
Z = High Impedance
Note 3:
X = Don’t care
If the DCON control bit goes high, the N-channel transistor
at the CPU_ON, IO_ON, CLK_ON and PGOOD pins turn on,
pulling these pins to ground. Any connected RUN/SS pins
are pulled to ground, shutting down the converters.
If the DCON control bit goes low, the N-channel transistor
at the CPU_ON, CLK_ON, IO_ON and PGOOD pins turn off
and become high impedance outputs. This allows the soft-
start capacitor at each RUN/SS pin to charge up and the
DC/DC converters wake up gradually with a soft-start
cycle. The PGOOD pin also pulls low for typically 50
μ
s to
indicate that the converter outputs are temporarily out of
regulation. An internal timer determines the duration of
the low pulse. The timer is triggered by SEL toggling or
DCON going low.
Power-Up Reset
On power-up, the internal POR circuit generates a low
reset pulse, which stays low until V
CC
rises above approxi-
mately 2.2V. The reset pulse forces the SMBus interface
into an idle state in which it listens for a start bit. At the
same time the outputs of both Register 0 and Register 1
are set to 11111B. The DCON bit is pulled high so that the
CPU_ON, IO_ON, CLK_ON and PGOOD pins are pulled low
to shut down the DC/DC converters.
APPLICATIU
W
U
U
Burst Mode is a trademark of Linear Technology Corporation.
相關PDF資料
PDF描述
LTC1699-81 SMBus VID Voltage Programmers(SMBus接口 VID電壓編程器)
LTC1699-82 SMBus VID Voltage Programmers(SMBus 接口VID電壓編程器)
LTC1701 Synchronous 8-Bit Up/Down Binary Counters 24-SOIC 0 to 70
LTC1701ES5 Synchronous 8-Bit Up/Down Binary Counters 24-SOIC 0 to 70
LTC1703 Synchronous 8-Bit Up/Down Binary Counters 24-PDIP 0 to 70
相關代理商/技術參數(shù)
參數(shù)描述
LTC1699EGN-80 功能描述:IC PROGRAMMER VOLT SMBUS 16SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 標準包裝:1 系列:- 應用:手持/移動設備 電流 - 電源:- 電源電壓:3 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-WFDFN 裸露焊盤 供應商設備封裝:14-LLP-EP(4x4) 包裝:Digi-Reel® 配用:LP3905SD-30EV-ND - BOARD EVALUATION LP3905SD-30 其它名稱:LP3905SD-30DKR
LTC1699EGN-80#PBF 功能描述:IC PROGRAMMER VOLT SMBUS 16SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 應用說明:Ultrasound Imaging Systems Application Note 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:37 系列:- 應用:醫(yī)療用超聲波成像,聲納 電流 - 電源:- 電源電壓:2.37 V ~ 6 V 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:56-WFQFN 裸露焊盤 供應商設備封裝:56-TQFN-EP(8x8) 包裝:管件
LTC1699EGN-80#TR 功能描述:IC PROGRAMMER VOLT SMBUS 16SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 標準包裝:1 系列:- 應用:手持/移動設備 電流 - 電源:- 電源電壓:3 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-WFDFN 裸露焊盤 供應商設備封裝:14-LLP-EP(4x4) 包裝:Digi-Reel® 配用:LP3905SD-30EV-ND - BOARD EVALUATION LP3905SD-30 其它名稱:LP3905SD-30DKR
LTC1699EGN-80#TRPBF 功能描述:IC PROGRAMMER VOLT SMBUS 16SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 應用說明:Ultrasound Imaging Systems Application Note 產(chǎn)品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:37 系列:- 應用:醫(yī)療用超聲波成像,聲納 電流 - 電源:- 電源電壓:2.37 V ~ 6 V 工作溫度:0°C ~ 70°C 安裝類型:表面貼裝 封裝/外殼:56-WFQFN 裸露焊盤 供應商設備封裝:56-TQFN-EP(8x8) 包裝:管件
LTC1699EGN-81 功能描述:IC PROGRAMMER VOLT SMBUS 16SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 電源管理 - 專用 系列:- 標準包裝:1 系列:- 應用:手持/移動設備 電流 - 電源:- 電源電壓:3 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:14-WFDFN 裸露焊盤 供應商設備封裝:14-LLP-EP(4x4) 包裝:Digi-Reel® 配用:LP3905SD-30EV-ND - BOARD EVALUATION LP3905SD-30 其它名稱:LP3905SD-30DKR