- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄98002 > LTC1955IUH#TR (LINEAR TECHNOLOGY CORP) 2-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC32 PDF資料下載
參數(shù)資料
| 型號(hào)： | LTC1955IUH#TR |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 電源管理 |
| 英文描述： | 2-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC32 |
| 封裝： | 5 X 5 MM, 0.75 MM HEIGHT, MO-220WHHD, QFN-32 |
| 文件頁數(shù)： | 20/20頁 |
| 文件大小： | 243K |
| 代理商： | LTC1955IUH#TR |
LTC1955
9
1955fb
OPERATION
Serial Port
The microcontroller compatible serial port provides all
of the command and control inputs for the LTC1955, as
well as the status of the two smart cards. Data on the
DIN input is loaded on the rising edge of SCLK. D15 is
loaded rst and D0 last. At the same time, the command
bits are being shifted into the DIN input, the status bits
are being shifted out of the DOUT output. The status bits
are presented to DOUT on the rising edge of SCLK. Once
all bits have been clocked into the shift register, the com-
mand data is loaded into the command latch by bringing
LD low. At this time, the command latch is updated and
the LTC1955 will begin to act on the new command set.
When LD is low, the shift register is transparent to the
status data of the two smart card channels. The status
data is latched into the shift register on the rising edge of
LD. SCLK should be held in the high state when idle and
should only be clocked when LD is high. Likewise, LD
should only be brought high when SCLK is high. Figure 1
shows the operation of the serial port.
Multiple LTC1955s may be daisychained together by
connecting the DOUT pin of one LTC1955 to the DIN pin of
another. Figure 6 shows an example of multiple LTC1955s
daisychained together.
The maximum clock rate for the serial port is 10MHz.
The serial port controls the following parameters of each
smart card socket:
Selection/deselection of a smart card
VCC voltage level of each card (5V/3V/1.8V/0V)
Clock mode of each card (synchronous or asynchronous)
Operating mode of asynchronous cards (clock stop
high, low, ÷1, ÷2, ÷4 or ÷8)
Selection of the I/O, C4 or C8 pins for card socket A
The serial port provides the following status data:
It indicates the presence or absence of the smart
cards.
It indicates the readiness of the smart card VCC supplies.
Communication with a smart card is disabled until its
power supply voltage has reached the nal value.
It indicates fault status. In the event of an electrical or
ATR fault, the fault is reported. For electrical faults, the
LTC1955 will automatically deactivate the smart card.
Table 1 illustrates the command inputs and status outputs
associated with each bit of the serial data word.
Three voltage options are available from the LTC1955: 5V,
3V and 1.8V. Bits D0, D1 (card B) and D8, D9 (card A)
determine which voltage is selected. Setting both control
bits of a channel to 0 deactivates that channel and sets
the smart card supply voltage to 0V. If both channels are
deactivated, the LTC1955 is in shutdown. Table 2 shows
the operation of the supply control bits.
The CLK A/CLK B pins to the smart cards can be pro-
grammed for various modes. Both synchronous and asyn-
chronous cards are supported. There are several options
available with asynchronous cards. Table 3 shows how
all clock options are obtained using bits D5–D7 (card B)
and D13–D15 (card A). The default state of the LTC1955
on power up is synchronous mode.
DIN
SCLK
LD
X
D0
D15
XD1
DOUT
D15 FROM
INPUT
D0
D15
1955 F01
D14
D13
D15
D1
tLC
tDH
tDD
tDS
tH
tL
tLW
tCL
D14
D2
Figure 1. Serial Port Timing Diagram
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC1955IUH | 2-CHANNEL POWER SUPPLY SUPPORT CKT, PQCC32 |
| LTC2900-1CMS#TRPFB | 4-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO10 |
| LTC3125EDCB#TRPBF | SWITCHING REGULATOR, 1900 kHz SWITCHING FREQ-MAX, PDSO8 |
| LTC3125EDCB#PBF | SWITCHING REGULATOR, 1900 kHz SWITCHING FREQ-MAX, PDSO8 |
| LTC3406ES5-1.2#PBF | 1.3 A SWITCHING REGULATOR, 1800 kHz SWITCHING FREQ-MAX, PDSO5 |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC1957-1EMS8 | 功能描述:IC RF PWR CONTRLLR SINGLE 8-MSOP RoHS:否 類別:RF/IF 和 RFID >> RF 電源控制器 IC 系列:- 標(biāo)準(zhǔn)包裝:3,000 系列:- RF 型:GSM 頻率:450MHz ~ 2GHz 特點(diǎn):四頻帶 封裝/外殼:8-VFBGA 供應(yīng)商設(shè)備封裝:8-MicroSMD（1.51x1.51） 包裝:帶卷 (TR) 其它名稱:LMV243BLX |
| LTC1957-1EMS8#PBF | 功能描述:IC RF PWR CONTRLLR SINGLE 8-MSOP RoHS:是 類別:RF/IF 和 RFID >> RF 電源控制器 IC 系列:- 標(biāo)準(zhǔn)包裝:3,000 系列:- RF 型:GSM 頻率:450MHz ~ 2GHz 特點(diǎn):四頻帶 封裝/外殼:8-VFBGA 供應(yīng)商設(shè)備封裝:8-MicroSMD（1.51x1.51） 包裝:帶卷 (TR) 其它名稱:LMV243BLX |
| LTC1957-1EMS8#TR | 功能描述:IC RF PWR CONTRLLR SINGLE 8-MSOP RoHS:否 類別:RF/IF 和 RFID >> RF 電源控制器 IC 系列:- 標(biāo)準(zhǔn)包裝:3,000 系列:- RF 型:GSM 頻率:450MHz ~ 2GHz 特點(diǎn):四頻帶 封裝/外殼:8-VFBGA 供應(yīng)商設(shè)備封裝:8-MicroSMD（1.51x1.51） 包裝:帶卷 (TR) 其它名稱:LMV243BLX |
| LTC1957-1EMS8#TRPBF | 功能描述:IC RF PWR CONTRLLR SINGLE 8-MSOP RoHS:是 類別:RF/IF 和 RFID >> RF 電源控制器 IC 系列:- 標(biāo)準(zhǔn)包裝:3,000 系列:- RF 型:GSM 頻率:450MHz ~ 2GHz 特點(diǎn):四頻帶 封裝/外殼:8-VFBGA 供應(yīng)商設(shè)備封裝:8-MicroSMD（1.51x1.51） 包裝:帶卷 (TR) 其它名稱:LMV243BLX |
| LTC1957-2EMS | 功能描述:IC RF PWR CONTROLLR DUAL 10-MSOP RoHS:否 類別:RF/IF 和 RFID >> RF 電源控制器 IC 系列:- 標(biāo)準(zhǔn)包裝:3,000 系列:- RF 型:GSM 頻率:450MHz ~ 2GHz 特點(diǎn):四頻帶 封裝/外殼:8-VFBGA 供應(yīng)商設(shè)備封裝:8-MicroSMD（1.51x1.51） 包裝:帶卷 (TR) 其它名稱:LMV243BLX |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。