- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385504 > LTC1556 (Linear Technology Corporation) SIM Power Supply and Level Translator(SMI電源和電平轉(zhuǎn)換器) PDF資料下載
參數(shù)資料
| 型號(hào)： | LTC1556 |
| 廠商： | Linear Technology Corporation |
| 英文描述： | SIM Power Supply and Level Translator(SMI電源和電平轉(zhuǎn)換器) |
| 中文描述： | SIM卡電源和電平轉(zhuǎn)換（學(xué)校管理新措施電源和電平轉(zhuǎn)換器） |
| 文件頁(yè)數(shù)： | 7/12頁(yè) |
| 文件大小： | 223K |
| 代理商： | LTC1556 |
7
LTC1555/LTC1556
The LTC1555/LTC1556 perform the two primary func-
tions necessary for 3V controllers (e.g., GSM cellular
telephone controllers, smart card readers, etc.) to com-
municate with 5V SIMs or smart cards. They produce a
regulated 5V V
CC
supply for the SIM and provide level
translators for communication between the SIM and the
controller.
V
CC
Voltage Regulator
The regulator section of the LTC1555/LTC1556 (refer to
the Block Diagram) consists of a step-up/step-down charge
pump DC/DC converter. The charge pump can operate
over a wide input voltage range (2.7V to 10V) while
maintaining a regulated V
CC
output. The wide V
IN
range
enables the parts to be powered directly from a battery (if
desired) rather than from a 3V DC/DC converter output.
When V
IN
is less than the desired V
CC
the parts operate as
switched capacitor voltage doublers. When V
IN
is greater
than V
CC
the parts operate as gated switch step-down
converters. In either case, voltage conversion requires
only one small flying capacitor and output capacitor.
The V
CC
output can be programmed to either 5V or 3V via
the M0 and M1 mode pins. This feature is useful in
applications where either a 5V or 3V SIM may be used. The
charge pump V
CC
output may also be connected directly to
V
IN
if desired. When the charge pump is put into shutdown
(M0, M1 = 0), V
CC
is pulled to GND via an internal switch
to aid in proper system supply sequencing.
The soft start feature limits inrush currents upon start-up
or coming out of shutdown mode. When the SS pin is tied
to GND, the soft start feature is enabled. This limits the ef-
fective inrush current out of V
IN
to approximately 25mA
(C
OUT
= 10
μ
F). Inrush current limiting is especially useful
when powering the LTC1555/LTC1556 from a 3V DC/DC
output since the unlimited inrush current may approach
200mA and cause voltage transients on the 3V supply. How-
ever, in cases where fast turn-on time is desired, the soft
start feature may be overridden by tying the SS pin to DV
CC
.
APPLICATIO
S I
FOR
ATIO
U
W
U
U
Capacitor Selection
For best performance, it is recommended that low ESR
(<0.5
) capacitors be used for both C
IN
and C
OUT
to reduce
noise and ripple. The C
IN
and C
OUT
capacitors should be
either ceramic or tantalum and should be 10
μ
F or greater
(ceramic capacitors will produce the smallest output ripple).
If the input source impedance is very low (<0.5
), C
IN
may
not be needed. Increasing the size of C
OUT
to 22
μ
F or greater
will reduce output voltage ripple—particularly with high V
IN
voltages (8V or greater). A ceramic capacitor is recom-
mended for the flying capacitor C1 with a value of 0.1
μ
F or
0.22
μ
F.
Output Ripple
Normal LTC1555/LTC1556 operation produces voltage
ripple on the V
CC
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
delays 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 (V
IN
< 8V) under maximum load is
75mV peak-to-peak with a low ESR, 10
μ
F output capaci-
tor. For applications requiring V
IN
to exceed 8V, a 22
μ
F or
larger C
OUT
capacitor is recommended to maintain maxi-
mum ripple in the 75mV range.
The magnitude of the ripple voltage depends on several
factors. High input voltages increase the output ripple
since more charge is delivered to C
OUT
per charging cycle.
A large C1 flying capacitor (> 0.22
μ
F) also increases ripple
in step-up mode for the same reason. Large output current
load and/or a small output capacitor (< 10
μ
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 V
OUT
with every clock cycle.
A 10
μ
F ceramic capacitor on the V
CC
pin should produce
acceptable levels of output voltage ripple in nearly all
applications. However, there are several ways to further
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LTC1559-5 | Backup Battery Controller with Fixed Output(帶固定輸出后備電池控制器) |
| LTC1560-1 | 1MHz/500kHz Continuous Time, Low Noise, Lowpass Elliptic Filter |
| LTC1560-1C | Advanced,Self-Calibrating, Precision, Dual Operational Amplifier 20-LCCC -55 to 125 |
| LTC1560-1CS8 | 1MHz/500kHz Continuous Time, Low Noise, Lowpass Elliptic Filter |
| LTC1560-1I | Advanced,Self-Calibrating, Precision, Dual Operational Amplifier 8-CDIP -55 to 125 |
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(wú)/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(yè)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(wú)/無(wú) 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(wú)/無(wú) 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(wú)/無(wú) 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(wú)/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(yè)面:1088 (CN2011-ZH PDF) 其它名稱:576-1360-6 |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。