- 您现在的位置：买卖IC网 > PDF目录1832 > LTC3827IG-1#TRPBF (Linear Technology)IC REG CTRLR BUCK PWM CM 28-SSOP PDF资料下载
参数资料
| 型号： | LTC3827IG-1#TRPBF |
| 厂商： | Linear Technology |
| 文件页数： | 13/32页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 28-SSOP |
| 标准包装： | 2,000 |
| 系列： | PolyPhase® |
| PWM 型： | 电流模式 |
| 输出数： | 2 |
| 频率 - 最大： | 580kHz |
| 占空比： | 99.4% |
| 电源电压： | 4 V ~ 36 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： | 28-SSOP（0.209"，5.30mm 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页第29页第30页第31页第32页
LTC3827-1
OPERATION (Refer to Functional Diagram)
duty cycles which, in turn, are dependent upon the input
3.0
voltage V IN (Duty Cycle = V OUT /V IN ). Figure 2 shows how
the RMS input current varies for single-phase and 2-phase
operation for 3.3V and 5V regulators over a wide input
2.5
2.0
SINGLE PHASE
DUAL CONTROLLER
voltage range.
1.5
It can readily be seen that the advantages of 2-phase op-
eration are not just limited to a narrow operating range,
for most applications is that 2-phase operation will reduce
the input capacitor requirement to that for just one channel
1.0
0.5
2-PHASE
DUAL CONTROLLER
V O1 = 5V/3A
V O2 = 3.3V/3A
operating at maximum current and 50% duty cycle.
0
0
10
20 30
40
The schematic on the ?rst page is a basic LTC3827-1 ap-
INPUT VOLTAGE (V)
38271 F02
plication circuit. External component selection is driven
by the load requirement, and begins with the selection of
R SENSE and the inductor value. Next, the power MOSFETs
are selected. Finally, C IN and C OUT are selected.
APPLICATIONS INFORMATION
R SENSE Selection For Output Current
R SENSE is chosen based on the required output current.
The current comparator has a maximum threshold of
100mV/R SENSE and an input common mode range of
SGND to 10V. The current comparator threshold sets the
peak of the inductor current, yielding a maximum average
output current I MAX equal to the peak value less half the
peak-to-peak ripple current, Δ I L .
Allowing a margin for variations in the IC and external
component values yields:
Figure 2. RMS Input Current Comparison
Operating Frequency and Synchronization
The choice of operating frequency, is a trade-off between
ef?ciency and component size. Low frequency operation
improves ef?ciency by reducing MOSFET switching losses,
both gate charge loss and transition loss. However, lower
frequency operation requires more inductance for a given
amount of ripple current.
The internal oscillator for each of the LTC3827-1’s controllers
runs at a nominal 400kHz frequency when the PLLLPF pin
is left ?oating and the PLLIN/MODE pin is a DC low or high.
R SENSE =
80mV
I MAX
Pulling the PLLLPF to INTV CC selects 530kHz operation;
pulling the PLLLPF to SGND selects 250kHz operation.
Alternatively, the LTC3827-1 will phase-lock to a clock
When using the controller in very low dropout conditions,
the maximum output current level will be reduced due to
the internal compensation required to meet stability cri-
terion for buck regulators operating at greater than 50%
duty factor. A curve is provided in the Typical Performance
Characteristics section to estimate this reduction in peak
output current level depending upon the operating duty
factor.
signal applied to the PLLIN/MODE pin with a frequency
between 140kHz and 650kHz (see Phase-Locked Loop
and Frequency Synchronization).
Inductor Value Calculation
The operating frequency and inductor selection are inter-
related in that higher operating frequencies allow the use
of smaller inductor and capacitor values. So why would
anyone ever choose to operate at lower frequencies with
38271fe
13
相关PDF资料 |
PDF描述 |
|---|---|
| LTC3828EUH#TRPBF | IC REG CTRLR BUCK PWM CM 32-QFN |
| LTC3829EFE#PBF | IC REG CTRLR BUCK PWM CM 38TSSOP |
| LTC3830ES8#PBF | IC REG CTRLR BUCK PWM VM 8-SOIC |
| LTC3831EGN | IC SW REG CONTROLLR SYNC 16-SSOP |
| LTC3832-1ES8#PBF | IC REG CTRLR BUCK PWM VM 8-SOIC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3827IUH#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 32-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 |
| LTC3827IUH#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 32-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 |
| LTC3828EG#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 28-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:2,000 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:1MHz 占空比:50% 电源电压:9 V ~ 10 V 降压:无 升压:是 回扫:是 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:8-TSSOP（0.173"，4.40mm 宽） 包装:带卷 (TR) |
| LTC3828EG#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 28-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 |
| LTC3828EUH | 制造商:Linear Technology 功能描述:DC DC Cntrlr Dual-OUT Sync Step Down 4.5V to 28V Input 32-Pin QFN EP |
发布紧急采购，3分钟左右您将得到回复。