- 您现在的位置：买卖IC网 > PDF目录15297 > LTC3855EFE#TRPBF (Linear Technology)IC REG CTRLR BUCK PWM CM 38TSSOP PDF资料下载
参数资料
| 型号： | LTC3855EFE#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 23/44页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 38TSSOP |
| 标准包装： | 2,000 |
| 系列： | PolyPhase® |
| PWM 型： | 电流模式 |
| 输出数： | 2 |
| 频率 - 最大： | 850kHz |
| 占空比： | 95% |
| 电源电压： | 4.5 V ~ 38 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： | 38-TFSOP （0.173"，4.40mm 宽）裸露焊盘 |
| 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页当前第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页
LTC3855
APPLICATIONS INFORMATION
producing a small offset error. To minimize this error, select
the tracking resistive divider value to be small enough to
make this error negligible.
In order to track down another channel or supply after
the soft-start phase expires, the LTC3855 is forced into
continuous mode of operation as soon as V FB is below the
undervoltage threshold of 0.54V regardless of the setting
on the MODE/PLLIN pin. However, the LTC3855 should
always be set in force continuous mode tracking down
when there is no load. After TK/SS drops below 0.1V, its
channel will operate in discontinuous mode.
Output Voltage Tracking
The LTC3855 allows the user to program how its output
ramps up and down by means of the TK/SS pins. Through
these pins, the output can be set up to either coincidentally
or ratiometrically track another supply’s output, as shown
in Figure 8. In the following discussions, V OUT1 refers to
the LTC3855’s output 1 as a master channel and V OUT2
refers to the LTC3855’s output 2 as a slave channel. In
practice, though, either phase can be used as the master.
V OUT1
V OUT2
To implement the coincident tracking in Figure 8a, con-
nect an additional resistive divider to V OUT1 and connect
its midpoint to the TK/SS pin of the slave channel. The
ratio of this divider should be the same as that of the slave
channel’s feedback divider shown in Figure 9a. In this
tracking mode, V OUT1 must be set higher than V OUT2 . To
implement the ratiometric tracking in Figure 9b, the ratio of
the V OUT2 divider should be exactly the same as the master
channel’s feedback divider shown in Figure 9b. By select-
ing different resistors, the LTC3855 can achieve different
modes of tracking including the two in Figure 8.
So which mode should be programmed? While either
mode in Figure 8 satisfies most practical applications,
some tradeoffs exist. The ratiometric mode saves a pair
of resistors, but the coincident mode offers better output
regulation.
When the master channel’s output experiences dynamic
excursion (under load transient, for example), the slave
channel output will be affected as well. For better output
regulation, use the coincident tracking mode instead of
ratiometric.
V OUT1
V OUT2
TIME
3855 F08a
TIME
3855 F08b
(8a) Coincident Tracking
(8b) Ratiometric Tracking
Figure 8. Two Different Modes of Output Voltage Tracking
V OUT1
V OUT2
V OUT1
V OUT2
TO
TK/SS2
PIN
R3
R4
R1
R2
TO
V FB1
PIN
TO
V FB2
PIN
R3
R4
TO
TK/SS2
PIN
R1
R2
TO
V FB1
PIN
TO
V FB2
PIN
R3
R4
3855 F09
(9a) Coincident Tracking Setup
(9b) Ratiometric Tracking Setup
Figure 9. Setup for Coincident and Ratiometric Tracking
3855f
相关PDF资料 |
PDF描述 |
|---|---|
| VE-JWF-EY-F3 | CONVERTER MOD DC/DC 72V 50W |
| LTC3835EFE#PBF | IC REG CTRLR BUCK PWM CM 20TSSOP |
| VE-JWK-EY-F3 | CONVERTER MOD DC/DC 40V 50W |
| VE-JWK-EY-F2 | CONVERTER MOD DC/DC 40V 50W |
| VE-JWJ-EY-F1 | CONVERTER MOD DC/DC 36V 50W |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3855EUJ#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 40-QFN 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 |
| LTC3855EUJ#PBF | 制造商:Linear Technology 功能描述:IC DUAL SYNC DC/DC CONTROLLER QFN-40 |
| LTC3855EUJ#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 40-QFN 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: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) |
| LTC3855IFE#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 38-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 |
| LTC3855IFE#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 38TSSOP 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 |
发布紧急采购，3分钟左右您将得到回复。