参数资料
| 型号： | LTC3730CG#TR |
| 厂商： | Linear Technology |
| 文件页数： | 16/28页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR BUCK POLYPHASE 36-SSOP |
| 标准包装： | 2,000 |
| 应用： | 控制器，Intel 移动式 VID |
| 输入电压： | 4 V ~ 36 V |
| 输出数： | 1 |
| 输出电压： | 0.6 V ~ 1.75 V |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 36-SSOP（0.209"，5.30mm 宽） |
| 供应商设备封装： | 36-SSOP |
| 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页第13页第14页第15页当前第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
LTC3730
APPLICATIO S I FOR ATIO
C OUT required ESR < N ? R SENSE
and
C OUT > 1/(8Nf)(R SENSE )
The emergence of very low ESR capacitors in small,
surface mount packages makes very small physical imple-
mentations possible. The ability to externally compensate
the switching regulator loop using the I TH pin allows a
much wider selection of output capacitor types. The
has a typical maximum threshold of 75mV/R SENSE and an
input common mode range of SGND to (1.1) ? V CC . The
current comparator threshold sets the peak inductor cur-
rent, 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 IC and external
component values yields:
impedance characteristics of each capacitor type is sig-
nificantly different than an ideal capacitor and therefore
requires accurate modeling or bench evaluation during
R SENSE = N
50mV
I MAX
design.
Manufacturers such as Nichicon, Nippon Chemi-Con and
Sanyo should be considered for high performance through-
hole capacitors. The OS-CON semiconductor dielectric
capacitor available from Sanyo and the Panasonic SP
surface mount types have a good (ESR)(size) product.
Once the ESR requirement for C OUT has been met, the
RMS current rating generally far exceeds the I RIPPLE(P-P)
requirement. Ceramic capacitors from AVX, Taiyo Yuden,
Murata and Tokin offer high capacitance value and very
low ESR, especially applicable for low output voltage
applications.
In surface mount applications, multiple capacitors may have
to be paralleled to meet the ESR or RMS current handling
requirements of the application. Aluminum electrolytic and
dry tantalum capacitors are both available in surface mount
configurations. New special polymer surface mount
capacitors offer very low ESR also but have much lower
capacitive density per unit volume. In the case of tantalum,
it is critical that the capacitors are surge tested for use in
switching power supplies. Several excellent choices are
the AVX TPS, AVX TPSV, the KEMET T510 series of sur-
face-mount tantalums or the Panasonic SP series of sur-
face mount special polymer capacitors available in case
heights ranging from 2mm to 4mm. Other capacitor types
include Sanyo POS CAP, Sanyo OS-CON, Nichicon PL series
and Sprague 595D series. Consult the manufacturers for
other specific recommendations.
R SENSE Selection for Output Current
Once the frequency and inductor have been chosen,
R SENSE1, R SENSE2, R SENSE3 are determined based on the
required peak inductor current. The current comparator
The IC works well with values of R SENSE from 0.002 ? to
0.02 ? .
V CC Decoupling
The V CC pin supplies power not only the internal circuits
of the controller but also the top and bottom gate drivers
on the IC and therefore must be bypassed very carefully
to ground with a ceramic capacitor, type X7R or X5R
(depending upon the operating temperature environ-
ment) of at least 1 μ F immediately next to the IC and
preferably an additional 10 μ F placed very close to the IC
due to the extremely high instantaneous currents in-
volved. The total capacitance, taking into account the
voltage coefficient of ceramic capacitors, should be 100
times as large as the total combined gate charge capaci-
tance of ALL of the MOSFETs being driven. Good bypass-
ing close to the IC is necessary to supply the high transient
currents required by the MOSFET gate drivers while keep-
ing the 5V supply quiet enough so as not to disturb the very
small-signal high bandwidth of the current comparators.
Topside MOSFET Driver Supply (C B , D B )
External bootstrap capacitors, C B , connected to the BOOST
pins, supply the gate drive voltages for the topside
MOSFETs. Capacitor C B in the Functional Diagram is
charged though diode D B from V CC when the SW pin is
low. When one of the topside MOSFETs turns on, the
driver places the C B voltage across the gate-source of the
desired MOSFET. This enhances the MOSFET and turns on
the topside switch. The switch node voltage, SW, rises to
V IN and the BOOST pin follows. With the topside MOSFET
on, the boost voltage is above the input supply (V BOOST =
V CC + V IN ). The value of the boost capacitor C B needs to be
3730fa
16
相关PDF资料 |
PDF描述 |
|---|---|
| EEM40DTAT-S189 | CONN EDGECARD 80POS R/A .156 SLD |
| AMC18DRTS | CONN EDGECARD 36POS .100 DIP SLD |
| RSM12DRKI-S13 | CONN EDGECARD 24POS .156 EXTEND |
| RBC65DREH-S13 | CONN EDGECARD 130PS .100 EXTEND |
| LT1182CS | IC SW REG CCFL/LCD CONTRST16SOIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3731CG | 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 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 ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LTC3731CG#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 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 |
| LTC3731CG#TR | 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 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 ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LTC3731CG#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 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 ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
| LTC3731CUH | 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:PolyPhase® 标准包装:4,500 系列:PowerWise® PWM 型:控制器 输出数:1 频率 - 最大:1MHz 占空比:95% 电源电压:2.8 V ~ 5.5 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 ~ 125°C 封装/外壳:6-WDFN 裸露焊盘 包装:带卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名称:LM1771SSDX |
发布紧急采购，3分钟左右您将得到回复。