參數(shù)資料
型號: LTC1551LCMS8
廠商: LINEAR TECHNOLOGY CORP
元件分類: 穩(wěn)壓器
英文描述: Advanced,Self-Calibrating, Precision, Dual Operational Amplifier 8-SOIC
中文描述: SWITCHED CAPACITOR REGULATOR, 900 kHz SWITCHING FREQ-MAX, PDSO8
封裝: PLASTIC, MSOP-8
文件頁數(shù): 9/12頁
文件大小: 271K
代理商: LTC1551LCMS8
9
LTC1550L/LTC1551L
APPLICATIO
S I
FOR
ATIO
U
Figure 4 shows a marked decrease in peak-to-peak output
ripple when a 0.1
μ
F ceramic capacitor is added in parallel
with the tantalum output capacitor. The additional ripple
with the tantalum output capacitor alone is mostly very
high order harmonics of the 900kHz clock, which appear
as sharp "spikes" at the output. The energy in these spikes
is very small and they do not contribute to the RMS output
voltage, but their peak-to-peak amplitude can be several
millivolts under some conditions. A 0.1
μ
F ceramic capaci-
tor has significantly lower impedance at the spike fre-
quency than a large tantalum capacitor, and eliminates
most of these left-over switching spikes that the tantalum
capacitor leaves behind. Figure 5 and 6 show scope photos
of the output of Figure 4 with and without the additional
ceramic capacitor at the output.
W
U
U
A series RC or LC filter can reduce high frequency output
noise even further. Due to the high 900kHz switching
frequency, not much R or L is required; a ferrite bead or a
relatively long PC board trace in series with 0.1
μ
F ceramic
capacitor will usually keep the output ripple well below
1mV
P-P
. Figure 1 shows an example of an ultralow noise
–2V generator. The corresponding spectrum and spot
noise plots for this circuit are shown in the Typical Perfor-
mance Characteristics section.
5
μ
s/DIV
1550L/51L F05
Figure 5. Output Ripple with 10
μ
F Tantalum Capacitor
V
AC COUPLE
5mV/DIV
Figure 3. Output Ripple Test Circuit
Figure 4. Output Ripple vs Output Capacitance
OUTPUT CAPACITANCE (
μ
F)
8
7
6
5
4
3
2
1
0
10
1550L/51L F04
O
P
)
1
100
V
CC
= 5V
T
A
= 25
°
C
C
IN
= 2.2
μ
F
WITHOUT 0.1
μ
F
WITH 0.1
μ
F
1
2
V
CC
8
7
REG
CP
OUT
SHDN
V
CC
C1
+
V
OUT
LTC1551L
GND
C1
C
OUT
10
μ
F
1550L/51L F03
V
–4.1V
C
CP
0.1
μ
F
C1
0.1
μ
F
C
IN
2.2
μ
F
3
4
6
5
C
L
0.1
μ
F
+
+
R1
10k
10
μ
s/DIV
1550L/51L F06
V
AC COUPLE
2mV/DIV
Figure 6. Output Ripple with 10
μ
F Tantalum
Capacitor Paralleled with 0.1
μ
F Ceramic Capacitor
相關(guān)PDF資料
PDF描述
LTC1551LCS8 Low Noise, Switched Capacitor Regulated Voltage Inverters
LTC1553CG 5-Bit Programmable Synchronous Switching Regulator Controller for Pentium II Processor
LTC1553CSW Advanced,Self-Calibrating, Precision, Dual Operational Amplifier 8-SOIC -55 to 125
LTC1553L 5-Bit Programmable Synchronous Switching Regulator Controller for Pentium II Processor
LTC1553LCG Advanced,Self-Calibrating, Precision, Dual Operational Amplifier 8-SOIC -40 to 125
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC1551LCMS8#PBF 功能描述:IC REG SWITCHD CAP INV ADJ 8MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:升壓(升壓) 輸出類型:可調(diào)式 輸出數(shù):1 輸出電壓:1.24 V ~ 30 V 輸入電壓:1.5 V ~ 12 V PWM 型:電流模式,混合 頻率 - 開關(guān):600kHz 電流 - 輸出:500mA 同步整流器:無 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC(0.154",3.90mm 寬) 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:8-SOIC
LTC1551LCMS8#TR 功能描述:IC REG SWITCHD CAP INV ADJ 8MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:升壓(升壓) 輸出類型:可調(diào)式 輸出數(shù):1 輸出電壓:1.24 V ~ 30 V 輸入電壓:1.5 V ~ 12 V PWM 型:電流模式,混合 頻率 - 開關(guān):600kHz 電流 - 輸出:500mA 同步整流器:無 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC(0.154",3.90mm 寬) 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:8-SOIC
LTC1551LCMS8#TRPBF 功能描述:IC REG SWITCHD CAP INV ADJ 8MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:升壓(升壓) 輸出類型:可調(diào)式 輸出數(shù):1 輸出電壓:1.24 V ~ 30 V 輸入電壓:1.5 V ~ 12 V PWM 型:電流模式,混合 頻率 - 開關(guān):600kHz 電流 - 輸出:500mA 同步整流器:無 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC(0.154",3.90mm 寬) 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:8-SOIC
LTC1551LCMS8-4.1 功能描述:IC REG SWITCHED CAP INV 8MSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:升壓(升壓) 輸出類型:可調(diào)式 輸出數(shù):1 輸出電壓:1.24 V ~ 30 V 輸入電壓:1.5 V ~ 12 V PWM 型:電流模式,混合 頻率 - 開關(guān):600kHz 電流 - 輸出:500mA 同步整流器:無 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC(0.154",3.90mm 寬) 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:8-SOIC
LTC1551LCMS8-4.1#PBF 功能描述:IC REG SWITCHED CAP INV 8MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 開關(guān)穩(wěn)壓器 系列:- 標(biāo)準(zhǔn)包裝:2,500 系列:- 類型:升壓(升壓) 輸出類型:可調(diào)式 輸出數(shù):1 輸出電壓:1.24 V ~ 30 V 輸入電壓:1.5 V ~ 12 V PWM 型:電流模式,混合 頻率 - 開關(guān):600kHz 電流 - 輸出:500mA 同步整流器:無 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC(0.154",3.90mm 寬) 包裝:帶卷 (TR) 供應(yīng)商設(shè)備封裝:8-SOIC