- 您现在的位置：买卖IC网 > PDF目录15309 > LTC1735CGN-1#TRPBF (Linear Technology)IC REG CTRLR BUCK PWM CM 16-SSOP PDF资料下载
参数资料
| 型号： | LTC1735CGN-1#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 13/28页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 16-SSOP |
| 标准包装： | 2,500 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 335kHz |
| 占空比： | 99.4% |
| 电源电压： | 3.5 V ~ 30 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： | 0°C ~ 85°C |
| 封装/外壳： | 16-SSOP（0.154"，3.90mm 宽） |
| 包装： | 带卷 (TR) |
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页第12页当前第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
LTC1735-1
APPLICATIO S I FOR ATIO
MOSFET from turning on and storing charge during the
dead-time, which could cost as much as 1% in efficiency.
A 3A Schottky is generally a good size for 10A to 12A regu-
lators due to the relatively small average current. Larger
diodes result in additional transition losses due to their
larger junction capacitance. The diode may be omitted if the
efficiency loss can be tolerated.
C IN Selection
In continuous mode, the source current of the top
N-channel MOSFET is a square wave of duty cycle V OUT /
V IN . To prevent large voltage transients, a low ESR input
capacitor sized for the maximum RMS current must be
used. The maximum RMS capacitor current is given by:
the output ripple will be less than 50mV at max V IN
assuming:
C OUT required ESR < 2.2 R SENSE
C OUT > 1/(8fR SENSE )
The first condition relates to the ripple current into the ESR
of the output capacitance while the second term guaran-
tees that the output voltage does not significantly dis-
charge during the operating frequency period due to ripple
current. The choice of using smaller output capacitance
increases the ripple voltage due to the discharging term
but can be compensated for by using capacitors of very
low ESR to maintain the ripple voltage at or below 50mV.
The I TH pin OPTI-LOOP compensation components can be
? I O ( MAX ) OUT ? IN – 1 ?
I RMS
V ? V ?
V IN ? V OUT ?
1 / 2
optimized to provide stable, high performance transient
response regardless of the output capacitors selected.
The selection of output capacitors for CPU or other appli-
This formula has a maximum at V IN = 2V OUT , where I RMS
= I OUT /2. This simple worst-case condition is commonly
used for design because even significant deviations do not
offer much relief. Note that capacitor manufacturer’s ripple
current ratings are often based on only 2000 hours of life.
This makes it advisable to further derate the capacitor, or
to choose a capacitor rated at a higher temperature than
required. Several capacitors may also be paralleled to
meet size or height requirements in the design. Always
consult the manufacturer if there is any question.
C OUT Selection
The selection of C OUT is primarily determined by the
effective series resistance (ESR) to minimize voltage ripple.
The output ripple ( ? V OUT ) in continuous mode is deter-
mined by:
cations with large load current transients is primarily de-
termined by the voltage tolerance specifications of the load.
The resistive component of the capacitor, ESR, multiplied
by the load current change plus any output voltage ripple
must be within the voltage tolerance of the load (CPU).
The required ESR due to a load current step is:
R ESR < ? V/ ? I
where ? I is the change in current from full load to zero load
(or minimum load) and ? V is the allowed voltage deviation
(not including any droop due to finite capacitance).
The amount of capacitance needed is determined by the
maximum energy stored in the inductor. The capacitance
must be sufficient to absorb the change in inductor current
when a high current to low current transition occurs. The
opposite load current transition is generally determined by
? V OUT L ? ESR +
8 fC OUT ?
≈ ? I
?
?
1 ?
?
the control loop OPTI-LOOP components, so make sure
not to over compensate and slow down the response. The
minimum capacitance to assure the inductors’ energy is
( )
L ? I
2 ( ) V OUT
wheref=operatingfrequency,C OUT =outputcapacitance,
and ? I L = ripple current in the inductor. The output ripple
is highest at maximum input voltage since ? I L increases
with input voltage. Typically, once the ESR requirement
for C OUT has been met, the RMS current rating generally
far exceeds the I RIPPLE(P-P) requirement. With ? I L =
adequately absorbed is:
2
C OUT >
? V
where ? I is the change in load current.
0.3I OUT(MAX) and allowing for 2/3 of the ripple due to ESR,
13
相关PDF资料 |
PDF描述 |
|---|---|
| UPS2E470MHD | CAP ALUM 47UF 250V 20% RADIAL |
| RBC20DRYI-S734 | CONN EDGECARD 40POS DIP .100 SLD |
| UPM2E330MHD1TN | CAP ALUM 33UF 250V 20% RADIAL |
| VI-2WD-EW-F2 | CONVERTER MOD DC/DC 85V 100W |
| VI-JWN-EW-F4 | CONVERTER MOD DC/DC 18.5V 100W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC1735CGNPBF | 制造商:Linear Technology 功能描述:Regulator Synch Step Down LTC1735CGN |
| LTC1735CS | 功能描述:IC REG CTRLR BUCK PWM CM 16-SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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 ~ 125°C 封装/外壳:24-WQFN 裸露焊盘 包装:带卷 (TR) |
| LTC1735CS#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 16-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 特色产品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 标准包装:1 系列:PowerWise® PWM 型:电压模式 输出数:1 频率 - 最大:1MHz 占空比:81% 电源电压:4.5 V ~ 18 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:-5°C ~ 125°C 封装/外壳:32-WFQFN 裸露焊盘 包装:Digi-Reel® 产品目录页面:1303 (CN2011-ZH PDF) 其它名称:LM3754SQDKR |
| LTC1735CS#TR | 功能描述:IC REG CTRLR BUCK PWM CM 16-SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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 ~ 125°C 封装/外壳:24-WQFN 裸露焊盘 包装:带卷 (TR) |
| LTC1735CS#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 16-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:96% 电源电压:4 V ~ 36 V 降压:无 升压:是 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 ~ 125°C 封装/外壳:24-WQFN 裸露焊盘 包装:带卷 (TR) |
发布紧急采购，3分钟左右您将得到回复。