- 您现在的位置：买卖IC网 > PDF目录15228 > LTC3890MPUH#PBF (Linear Technology)IC REG CTRLR BUCK PWM CM 32-QFN PDF资料下载
参数资料
| 型号： | LTC3890MPUH#PBF |
| 厂商： | Linear Technology |
| 文件页数： | 15/40页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 32-QFN |
| 标准包装： | 73 |
| 系列： | PolyPhase® |
| PWM 型： | 电流模式 |
| 输出数： | 2 |
| 频率 - 最大： | 850kHz |
| 占空比： | 99% |
| 电源电压： | 4 V ~ 60 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： | -55°C ~ 150°C |
| 封装/外壳： | 32-WFQFN 裸露焊盘 |
| 包装： | 管件 |
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页当前第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页第33页第34页第35页第36页第37页第38页第39页第40页
LTC3890
APPLICATIONS INFORMATION
The Typical Application on the first page is a basic LTC3890
application circuit. LTC3890 can be configured to use
either DCR (inductor resistance) sensing or low value
resistor sensing. The choice between the two current
sensing schemes is largely a design trade-off between
cost, power consumption and accuracy. DCR sensing
is becoming popular because it saves expensive current
sensing resistors and is more power efficient, especially
in high current applications. However, current sensing
resistors provide the most accurate current limits for the
controller. Other external component selection is driven
by the load requirement, and begins with the selection of
R SENSE (if R SENSE is used) and inductor value. Next, the
power MOSFETs and Schottky diodes are selected. Finally,
input and output capacitors are selected.
Filter components mutual to the sense lines should be
placed close to the LTC3890, and the sense lines should
run close together to a Kelvin connection underneath the
current sense element (shown in Figure 3). Sensing cur-
rent elsewhere can effectively add parasitic inductance
and capacitance to the current sense element, degrading
the information at the sense terminals and making the
programmed current limit unpredictable. If inductor DCR
sensing is used (Figure 4b), sense resistor R1 should be
TO SENSE FILTER,
NEXT TO THE CONTROLLER
C OUT
3890 F03
INDUCTOR OR R SENSE
Figure 3. Sense Lines Placement with Inductor or Sense Resistor
R SENSE
SENSE +
SENSE –
CurrentLimitProgramming
The I LIM pin is a tri-level logic input which sets the maxi-
mum current limit of the controller. When I LIM is grounded,
the maximum current limit threshold voltage of the cur-
rent comparator is programmed to be 30mV. When I LIM
is floated, the maximum current limit threshold is 75mV.
When I LIM is tied to INTV CC , the maximum current limit
threshold is set to 50mV.
SENSE + and SENSE – Pins
The SENSE + and SENSE – pins are the inputs to the cur-
rent comparators. The common mode voltage range on
these pins is 0V to 28V (abs max), enabling the LTC3890
to regulate output voltages up to a nominal 24V (allowing
margin for tolerances and transients).
V IN V IN
INTV CC
BOOST
TG
SW
LTC3890
BG
R1*
C1* PLACE CAPACITOR NEAR
SENSE PINS
SGND
*R1 AND C1 ARE OPTIONAL.
(4a) Using a Resistor to Sense Current
V IN V IN
INTV CC
V OUT
3890 F04a
The SENSE + pin is high impedance over the full common
mode range, drawing at most ±1μA. This high impedance
allows the current comparators to be used in inductor
DCR sensing.
BOOST
TG
SW
LTC3890
BG
INDUCTOR
L DCR
V OUT
(R1||R2) ? C1 =
*PLACE C1 NEAR
R SENSE(EQ) = DCR
SENSE PINS
TheimpedanceoftheSENSE – pinchangesdependingon
the common mode voltage. When SENSE – is less than
INTV CC – 0.5V, a small current of less than 1μA flows out
of the pin. When SENSE – is above INTV CC + 0.5V, a higher
current (~700μA) flows into the pin. Between INTV CC –
0.5V and INTV CC + 0.5V, the current transitions from the
smaller current to the higher current.
R1
SENSE +
C1* R2
SENSE –
SGND
L R2
DCR R1 + R2
(4b) Using the Inductor DCR to Sense Current
3890 F04b
Figure 4. Current Sensing Methods
3890fc
15
相关PDF资料 |
PDF描述 |
|---|---|
| ELL-6PV330M | COIL PWR CHOKE 33UH 600MA SMD |
| ELL-6PV270M | COIL PWR CHOKE 27UH 670MA SMD |
| ELL-6PV220M | COIL PWR CHOKE 22UH 700MA SMD |
| ELL-6PV180M | COIL PWR CHOKE 18UH 840MA SMD |
| ELL-6PV150M | COIL PWR CHOKE 15UH 880MA SMD |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LTC3891EFE#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 20TSSOP 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 |
| LTC3891EFE#PBF | 制造商:Linear Technology 功能描述:IC DC-DC CONV 900kHz TSSOP20 |
| LTC3891EFE#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 20TSSOP 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) |
| LTC3891EUDC#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 20-QFN 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 |
| LTC3891EUDC#PBF | 制造商:Linear Technology 功能描述:IC DC-DC CONV 900kHz QFN20 |
发布紧急采购，3分钟左右您将得到回复。