- 您现在的位置：买卖IC网 > PDF目录15303 > LTC1735CGN#TRPBF (Linear Technology)IC REG CTRLR BUCK PWM CM 16-SSOP PDF资料下载
参数资料
| 型号： | LTC1735CGN#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 26/32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： | 4 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页当前第26页第27页第28页第29页第30页第31页第32页
LTC1735
APPLICATIO S I FOR ATIO
Next verify the minimum on-time of 200ns is not violated.
The minimum on-time occurs at maximum V IN :
C IN is chosen for an RMS current rating of at least 2.5A at
temperature. C OUT is chosen with an ESR of 0.02 ? for low
output ripple. The output ripple in continuous mode will be
t ON ( MIN ) =
V OUT
V IN ( MAX ) f
=
1 . 8 V
22 V ( 300 kHz )
= 273 ns
highest at the maximum input voltage. The worst-case
output voltage ripple due to ESR is approximately:
R 1 ( MAX ) = 24 k ?
? 2 . 4 V – V OUT ?
= 24 k ?
? = 32 k
( 5 ) 2 [ 1 + ( 0 . 005 )( 50 ° C – 25 ° C ) ] ( 0 . 035 ? )
P MAIN =
+ 1 . 7 ( 22 V ) ( 5 A )( 100 pF )( 300 kHz )
Sincetheoutputvoltageisbelow2.4Vtheoutputresistive
divider will need to be sized to not only set the output
voltage but also to absorb the sense pin current.
? 0 . 8 V ?
?
? 0 . 8 V ?
? 2 . 4 V – 1 . 8 V ?
Choosing 1% resistors: R1 = 25.5k and R2 = 32.4k yields
an output voltage of 1.816V.
The power dissipation on the topside MOSFET can be
easily estimated. Choosing a Siliconix Si4412ADY results
in R DS(ON) = 0.035 ? , C RSS = 100pF. At maximum input
voltage with T(estimated) = 50 ° C:
1 .8 V
22 V
2
= 204 mW
Because the duty cycle of the bottom MOSFET is much
greater than the top, a larger MOSFET, Siliconix Si4410DY,
(R DS(ON) = 0.02 ? ) is chosen. The power dissipation in the
bottom MOSFET, again assuming T A = 50 ° C, is:
V ORIPPLE = R ESR ( ? I L ) = 0 . 02 ? ( 2 . 3 A ) = 46 mV P ? P
PC Board Layout Checklist
When laying out the printed circuit board, the following
checklist should be used to ensure proper operation of the
LTC1735. These items are also illustrated graphically in
the layout diagram of Figure 12. Check the following in
your layout:
1) Are the signal and power grounds segregated? The
LTC1735 PGND pin should tie to the ground plane close to
the input capacitor(s). The SGND pin should then connect
to PGND, and all components that connect to SGND
should make a single point tie to the SGND pin. The
synchronous MOSFET source pins should connect to the
input capacitor(s) ground.
2) Does the V OSENSE pin connect directly to the feedback
resistors? The resistive divider R1, R2 must be connected
between the (+) plate of C OUT and signal ground. The 47pF
to 100pF capacitor should be as close as possible to the
LTC1735. Be careful locating the feedback resistors too far
away from the LTC1735. The V OSENSE line should not be
routed close to any other nodes with high slew rates.
3) Are the SENSE – and SENSE + leads routed together with
minimum PC trace spacing? The filter capacitor between
SENSE + and SENSE – should be as close as possible to the
LTC1735. Ensure accurate current sensing with Kelvin
P SYNC =
22 V – 1. 8 V
22 V
( 5 A ) ( 2 1 . 1 ) ( 0 . 02 ? )
connections as shown in Figure 13. Series resistance can
be added to the SENSE lines to increase noise rejection.
= 505 mW
Thanks to current foldback, the bottom MOSFET dissipa-
tion in short-circuit will be less than under full load
conditions.
4) Does the (+) terminal of C IN connect to the drain of the
topside MOSFET(s) as closely as possible? This capacitor
provides the AC current to the MOSFET(s).
5) Is the INTV CC decoupling capacitor connected closely
between INTV CC and the power ground pin? This capaci-
tor carries the MOSFET driver peak currents. An addi-
tional 1 μ F ceramic capacitor placed immediately next to
1735fc
26
相关PDF资料 |
PDF描述 |
|---|---|
| ESC15DRTI-S93 | CONN EDGECARD 30POS DIP .100 SLD |
| LTC3770EUH#PBF | IC REG CTRLR BUCK PWM CM 32-QFN |
| VI-JWF-EW-F1 | CONVERTER MOD DC/DC 72V 100W |
| TVX2W2R2MCD | CAP ALUM 2.2UF 450V 20% AXIAL |
| VE-JWB-EY-F2 | CONVERTER MOD DC/DC 95V 50W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 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) |
| LTC1735CS-1 | 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) |
发布紧急采购，3分钟左右您将得到回复。