- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄8875 > LTC1555LEGN-1.8 (Linear Technology)IC LEVEL TRANSLATER 16-SSOP PDF資料下載
參數(shù)資料
| 型號： | LTC1555LEGN-1.8 |
| 廠商： | Linear Technology |
| 文件頁數(shù)： | 6/8頁 |
| 文件大小： | 0K |
| 描述： | IC LEVEL TRANSLATER 16-SSOP |
| 標(biāo)準(zhǔn)包裝： | 100 |
| 邏輯功能： | 電平移位器 |
| 位數(shù)： | 1 |
| 輸入類型： | 電壓 |
| 輸出類型： | 電壓 |
| 通道數(shù)： | 1 |
| 輸出/通道數(shù)目： | 1 |
| 差分 - 輸入:輸出： | 無/無 |
| 傳輸延遲（最大）： | 18ns |
| 電源電壓： | 1.8 V ~ 5.5 V |
| 工作溫度： | -40°C ~ 85°C |
| 封裝/外殼： | 16-SSOP（0.154"，3.90mm 寬） |
| 供應(yīng)商設(shè)備封裝： | 16-SSOP |
| 包裝： | 管件 |
LTC1555L-1.8
6
APPLICATIO S I FOR ATIO
WU
U
The LTC1555L-1.8 performs the two primary functions
necessary for low voltage controllers (e.g., GSM cellular
telephone controllers, smart card readers, etc.) to com-
municate with 5V SIMs or smart cards. The part produces
a regulated 1.8V, 3V or 5V VCC supply for the SIM, and also
provides level translators for communication between the
SIM and the controller.
VCC Voltage Regulator
The regulator section of the LTC1555L-1.8 (refer to Block
Diagram) consists of a buck/boost charge pump DC/DC
converter. The charge pump can operate over a wide input
voltage range (2.6V to 6V) while maintaining a regulated
VCC output. The wide VIN range enables the part to be
powered directly from a battery (if desired) rather than
from a DC/DC converter output. When VIN is less than the
selected VCC voltage, the part operates as a switched
capacitor voltage doubler. When VIN is greater than VCC,
the part operates as gated switch step-down converter. In
either case, voltage conversion requires only one small
flying capacitor and output capacitor.
The VCC output can be programmed via the M0-M2 pins to
either 1.8V, 3V, 5V or direct connection to VIN. This
flexibility is useful in applications where multiple voltage
SIMs may be used. When the charge pump is put into
shutdown (M0, M1 = 0), VCC is pulled to GND via an
internal switch to aid in proper system supply sequencing.
An internal soft-start feature helps to limit inrush currents
upon start-up or when coming out of shutdown mode.
Inrush current limiting is especially useful when powering
the LTC1555L-1.8 from a DC/DC output since the unlim-
ited inrush current may approach 300mA and cause
voltage transients on the 3V supply. The part is fully short-
circuit and over temperature protected, and can survive an
indefinite short from VCC to GND.
Capacitor Selection
For best performance, it is recommended that low ESR
(< 0.5
)capacitorsbeusedforbothCINandCOUTtoreduce
noise and ripple. The CIN and COUT capacitors should be
either ceramic or tantalum and should be 1
F or greater
(ceramic capacitors will produce the smallest output ripple).
If the input source impedance is very low (< 0.5
),CINmay
not be needed. Increasing the size of COUTto2.2Forgreater
will reduce output voltage ripple—particularly with high VIN
voltages (4V or greater). A ceramic capacitor is recom-
mended for the flying capacitor C1 with a value of 0.1
F or
0.22
F.
Output Ripple
Normal LTC1555L-1.8 operation produces voltage ripple
on the VCC pin. Output voltage ripple is required for the
parts to regulate. Low frequency ripple exists due to the
hysteresis in the sense comparator and propagation de-
lays in the charge pump enable/disable circuits. High
frequency ripple is also present mainly from the ESR
(equivalent series resistance) in the output capacitor.
Typical output ripple (VIN < 4V) under maximum load is
75mV peak-to-peak with a low ESR, 2.2
F output capaci-
tor (VCC = 5V).
The magnitude of the ripple voltage depends on several
factors. High input voltages increase the output ripple
since more charge is delivered to COUT per charging cycle.
A large C1 flying capacitor (> 0.22
F) also increases ripple
in step-up mode for the same reason. Large output current
load and/or a small output capacitor (< 1
F) results in
higher ripple due to higher output voltage dV/dt. High ESR
capacitors (ESR > 0.5
) on the output pin cause high
frequency voltage spikes on VOUT with every clock cycle.
A 2.2
F ceramic capacitor on the VCC pin should produce
acceptable levels of output voltage ripple in nearly all
applications. Also, in order to keep noise down all capaci-
tors should be placed close to LTC1555L-1.8.
Level Translators
All SIMs and smart cards contain a clock input, a reset
input, and a bidirectional data input/output. The
LTC1555L-1.8 provides level translators to allow
controllers to communicate with the SIM. (See Figure 1a
and 1b). The CLK and RST inputs to the SIM are level
shifted from the controller supply rails (DVCC and GND) to
the SIM supply rails (VCC and GND). The data input to the
SIM may be provided two different ways. The first method
is to use the DATA pin as a bidirectional level translator.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC1555LEGN#TRPBF | IC LEVEL TRANSLATOR 16-SSOP |
| LTC1555LEGN#PBF | IC LEVEL TRANSLATOR 16-SSOP |
| LTC1555LEGN | IC LEVEL TRANSLATER 16-SSOP |
| SY89325VMG TR | IC XLATOR CML/PECL/LV-LVDS 8MLF |
| SY100ELT25ZG TR | IC TRANSLATOR DIFF 8-SOIC |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LTC1556CGN | 功能描述:IC LEVEL TRANSLTOR W/LDO 20SSOP RoHS:否 類別:集成電路 (IC) >> 邏輯 - 變換器 系列:- 標(biāo)準(zhǔn)包裝:1 系列:100ELT 邏輯功能:變換器 位數(shù):1 輸入類型:TTL 輸出類型:差分 數(shù)據(jù)速率:- 通道數(shù):2 輸出/通道數(shù)目:1 差分 - 輸入:輸出:無/是 傳輸延遲（最大）:0.6ns 電源電壓:3 V ~ 3.8 V 工作溫度:-40°C ~ 85°C 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:8-SOIC 包裝:Digi-Reel® 產(chǎn)品目錄頁面:1088 (CN2011-ZH PDF) 其它名稱:576-1360-6 |
| LTC1556CGN#PBF | 功能描述:IC LEVEL TRANSLTOR W/LDO 20SSOP RoHS:是 類別:集成電路 (IC) >> 邏輯 - 變換器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:100 系列:- 邏輯功能:變換器，雙向 位數(shù):2 輸入類型:CMOS 輸出類型:CMOS 數(shù)據(jù)速率:16Mbps 通道數(shù):2 輸出/通道數(shù)目:1 差分 - 輸入:輸出:無/無 傳輸延遲（最大）:15ns 電源電壓:1.65 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 封裝/外殼:10-UFQFN 供應(yīng)商設(shè)備封裝:10-UTQFN（1.4x1.8） 包裝:管件 |
| LTC1556CGN#TR | 功能描述:IC LEVEL XLATOR/SIM PS 20SSOP RoHS:否 類別:集成電路 (IC) >> 邏輯 - 變換器 系列:- 產(chǎn)品培訓(xùn)模塊:Logic Packages 標(biāo)準(zhǔn)包裝:2,500 系列:- 邏輯功能:變換器，雙向 位數(shù):2 輸入類型:電壓 輸出類型:電壓 數(shù)據(jù)速率:- 通道數(shù):2 輸出/通道數(shù)目:1 差分 - 輸入:輸出:無/無 傳輸延遲（最大）:1.5ns 電源電壓:3 V ~ 3.6 V 工作溫度:-40°C ~ 85°C 封裝/外殼:8-TSSOP，8-MSOP（0.118"，3.00mm 寬） 供應(yīng)商設(shè)備封裝:8-TSSOP 包裝:帶卷 (TR) 其它名稱:935284857118GTL2002DP/S440-TGTL2002DP/S440-T-ND |
| LTC1556CGN#TRPBF | 功能描述:IC LEVEL TRANSLTOR W/LDO 20SSOP RoHS:是 類別:集成電路 (IC) >> 邏輯 - 變換器 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:100 系列:- 邏輯功能:變換器，雙向 位數(shù):2 輸入類型:CMOS 輸出類型:CMOS 數(shù)據(jù)速率:16Mbps 通道數(shù):2 輸出/通道數(shù)目:1 差分 - 輸入:輸出:無/無 傳輸延遲（最大）:15ns 電源電壓:1.65 V ~ 5.5 V 工作溫度:-40°C ~ 85°C 封裝/外殼:10-UFQFN 供應(yīng)商設(shè)備封裝:10-UTQFN（1.4x1.8） 包裝:管件 |
| LTC1556IGN | 功能描述:IC LEVEL TRANSLTOR W/LDO 20SSOP RoHS:否 類別:集成電路 (IC) >> 邏輯 - 變換器 系列:- 標(biāo)準(zhǔn)包裝:1 系列:100ELT 邏輯功能:變換器 位數(shù):1 輸入類型:TTL 輸出類型:差分 數(shù)據(jù)速率:- 通道數(shù):2 輸出/通道數(shù)目:1 差分 - 輸入:輸出:無/是 傳輸延遲（最大）:0.6ns 電源電壓:3 V ~ 3.8 V 工作溫度:-40°C ~ 85°C 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:8-SOIC 包裝:Digi-Reel® 產(chǎn)品目錄頁面:1088 (CN2011-ZH PDF) 其它名稱:576-1360-6 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。