参数资料
型号: LTC1649CS
厂商: Linear Technology
文件页数: 14/16页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM VM 16-SOIC
标准包装: 50
PWM 型: 电压模式
输出数: 1
频率 - 最大: 260kHz
占空比: 93%
电源电压: 2.7 V ~ 5 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: 0°C ~ 70°C
封装/外壳: 16-SOIC(0.154",3.90mm 宽)
包装: 管件
产品目录页面: 1333 (CN2011-ZH PDF)
LTC1649
APPLICATIO N S I N FOR M ATIO N
and output capacitors, the source of Q2, the LTC1649 GND
pin, the output return and the input supply return all
clustered at one point. Figure 9 is a modified schematic
showing the common connections in a proper layout. Note
that at 10A current levels or above, current density in the
PC board itself can become a concern; traces carrying high
currents should be as wide as possible.
Power Component Hook-Up/Heat Sinking
As current levels rise much above 1A, the power compo-
nents supporting the LTC1649 start to become physically
large (relative to the LTC1649, at least) and can require
special mounting considerations. Input and output ca-
pacitors need to carry high peak currents and must have
low ESR; this mandates that the leads be clipped as short
as possible and PC traces be kept wide and short. The
power inductor will generally be the most massive single
component on the board; it can require a mechanical hold-
down in addition to the solder on its leads, especially if it
is a surface mount type.
The power MOSFETs used require some care to ensure
proper operation and reliability. Depending on the current
levels and required efficiency, the MOSFETs chosen may
be as large as TO-220s or as small as SO-8s. High
efficiency circuits may be able to avoid heat sinking the
power devices, especially with TO-220 type MOSFETs. As
an example, a 90% efficient converter working at a steady
2.5V/10A output will dissipate only (25W/90%)10% =
2.8W. The power MOSFETs generally account for the
majority of the power lost in the converter; even assuming
that they consume 100% of the power used by the
converter, that’s only 2.8W spread over two or three
devices. A typical SO-8 MOSFET with a R ON suitable to
provide 90% efficiency in this design can commonly
dissipate 2W when soldered to an appropriately sized
piece of copper trace on a PC board. Slightly less efficient
or higher output current designs can often get by with
standing a TO-220 MOSFET straight up in an area with
some airflow; such an arrangement can dissipate as much
as 3W without a heat sink. Designs which must work in
high ambient temperatures or which will be routinely
overloaded will generally fare best with a heat sink.
V IN
D CP
+
V IN
PV CC2
PV CC1
C IN
22 ?
CP OUT
G1
+
10 μ F
1k
1 μ F
Q1
L1
V CC
LTC1649
I FB
0.1 μ F
V OUT
+
10 μ F
1 μ F
C +
I MAX
R IMAX
R1
C –
COMP
G2
FB
Q2
+
C OUT
C1
R C
C C
SS
C SS
GND
SHDN
R2
14
SHDN
Figure 9. Typical Schematic Showing Layout Considerations
1649 F09
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LTC1649CS#PBF 功能描述:IC REG CTRLR BUCK PWM VM 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
LTC1649CS#TR 功能描述:IC REG CTRLR BUCK PWM VM 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)
LTC1649CS#TRPBF 功能描述:IC REG CTRLR BUCK PWM VM 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)
LTC1649IS 功能描述:IC REG CTRLR BUCK PWM VM 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: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
LTC1649IS#PBF 功能描述:IC REG CTRLR BUCK PWM VM 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: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