- 您现在的位置：买卖IC网 > PDF目录15237 > LTC1629IG-PG#PBF (Linear Technology)IC REG CTRLR BUCK PWM CM 28-SSOP PDF资料下载
参数资料
| 型号： | LTC1629IG-PG#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 12/28页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 28-SSOP |
| 标准包装： | 47 |
| 系列： | PolyPhase® |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 360kHz |
| 占空比： | 99.5% |
| 电源电压： | 4 V ~ 36 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 28-SSOP（0.209"，5.30mm 宽） |
| 包装： | 管件 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页当前第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页
LTC1629/LTC1629-PG
APPLICATIO S I FOR ATIO
R SENSE Selection For Output Current
R SENSE1, 2 are chosen based on the required output
current. The LTC1629 current comparator has a maxi-
mum threshold of 75mV/R SENSE and an input common
mode range of SGND to 1.5( INTV CC ). The current com-
parator threshold sets the peak inductor current, yielding
a maximum average output current I MAX equal to the peak
value less half the peak-to-peak ripple current, ? I L .
Allowing a margin for variations in the LTC1629 and
2.5
2.0
1.5
1.0
0.5
0
external component values yields:
120
170 220 270
OPERATING FREQUENCY (kHz)
320
R SENSE = (50mV/I MAX )N
where N = number of stages.
When using the controller in very low dropout conditions,
the maximum output current level will be reduced due to
internal slope compensation required to meet stability
criterion for buck regulators operating at greater than 50%
duty factor. A curve is provided to estimate this reduction
in peak output current level depending upon the operating
duty factor.
Operating Frequency
The LTC1629 uses a constant frequency, phase-lockable
architecture with the frequency determined by an internal
1629 F02
Figure 2. Operating Frequency vs V PLLFLTR
MOSFET gate charge and transition losses. In addition to
this basic tradeoff, the effect of inductor value on ripple
current and low current operation must also be consid-
ered. The PolyPhase approach reduces both input and
output ripple currents while optimizing individual output
stages to run at a lower fundamental frequency, enhancing
efficiency.
The inductor value has a direct effect on ripple current. The
inductor ripple current ? I L per individual section, N,
decreases with higher inductance or frequency and in-
creases with higher V IN or V OUT :
? 1 ?
fL ?
V IN ?
capacitor.Thiscapacitorischargedbyafixedcurrentplus
an additional current which is proportional to the voltage
applied to the PLLFLTR pin. Refer to Phase-Locked Loop
and Frequency Synchronization in the Applications Infor-
? I L =
V OUT ? V OUT ?
?
mation section for additional information.
A graph for the voltage applied to the PLLFLTR pin vs
frequency is given in Figure 2. As the operating frequency
is increased the gate charge losses will be higher, reducing
efficiency (see Efficiency Considerations). The maximum
switching frequency is approximately 310kHz.
Inductor Value Calculation and Output Ripple Current
The operating frequency and inductor selection are inter-
related in that higher operating frequencies allow the use
of smaller inductor and capacitor values. So why would
anyone ever choose to operate at lower frequencies with
larger components? The answer is efficiency. A higher
frequency generally results in lower efficiency because of
12
where f is the individual output stage operating frequency.
In a PolyPhase converter, the net ripple current seen by the
output capacitor is much smaller than the individual
inductor ripple currents due to the ripple cancellation. The
details on how to calculate the net output ripple current
can be found in Application Note 77.
Figure 3 shows the net ripple current seen by the output
capacitors for the different phase configurations. The
output ripple current is plotted for a fixed output voltage as
the duty factor is varied between 10% and 90% on the
x-axis. The output ripple current is normalized against the
inductor ripple current at zero duty factor. The graph can
be used in place of tedious calculations. As shown in
Figure 3, the zero output ripple current is obtained when:
相关PDF资料 |
PDF描述 |
|---|---|
| VE-J7N-EY-F3 | CONVERTER MOD DC/DC 18.5V 50W |
| H2AAT-10104-N8-ND | JUMPER-H1502TR/A3048N/H1502TR 4" |
| LTC1629IG-PG | IC REG CTRLR BUCK PWM CM 28-SSOP |
| LTC3703IGN-5#PBF | IC REG CTRLR BST PWM VM 16-SSOP |
| LT3757MPMSE#TRPBF | IC REG CTRLR PWM CM 10-MSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC1642ACGN | 制造商:Linear Technology 功能描述:Hot Swap Controller 1-CH 16.5V 16-Pin SSOP N |
| LTC1642ACGN#PBF | 功能描述:IC CONTROLLER HOTSWAP ADJ 16SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:100 系列:- 类型:热插拔开关 应用:通用 内部开关:是 电流限制:可调 电源电压:9 V ~ 13.2 V 工作温度:-40°C ~ 150°C 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-TDFN-EP（3x3） 包装:管件 |
| LTC1642ACGN#TRPBF | 功能描述:IC CONTROLLER HOTSWAP ADJ 16SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:100 系列:- 类型:热插拔开关 应用:通用 内部开关:是 电流限制:可调 电源电压:9 V ~ 13.2 V 工作温度:-40°C ~ 150°C 安装类型:表面贴装 封装/外壳:10-WFDFN 裸露焊盘 供应商设备封装:10-TDFN-EP（3x3） 包装:管件 |
| LTC1642AIGN | 制造商:Linear Technology 功能描述:Hot Swap Controller 1-CH 16.5V 16-Pin SSOP N |
| LTC1642AIGN#PBF | 功能描述:IC CONTROLLER HOTSWAP ADJ 16SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热交换 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:119 系列:- 类型:热交换控制器 应用:通用型，PCI Express? 内部开关:无 电流限制:- 电源电压:3.3V，12V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:80-TQFP 供应商设备封装:80-TQFP（12x12） 包装:托盘 产品目录页面:1423 (CN2011-ZH PDF) |
发布紧急采购，3分钟左右您将得到回复。