参数资料
型号: LTC3828EUH#TRPBF
厂商: Linear Technology
文件页数: 19/32页
文件大小: 0K
描述: IC REG CTRLR BUCK PWM CM 32-QFN
标准包装: 2,500
系列: PolyPhase®
PWM 型: 电流模式
输出数: 2
频率 - 最大: 590kHz
占空比: 99.4%
电源电压: 4.5 V ~ 28 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -40°C ~ 85°C
封装/外壳: 32-WFQFN 裸露焊盘
包装: 带卷 (TR)
LTC3828
APPLICATIONS INFORMATION
V OUT = 0 . 8 V ? 1 +
?
bypassing is necessary to supply the high transient cur-
rents required by the MOSFET gate drivers and to prevent
interaction between channels.
?
?
R 2 ?
R 1 ?
R 1 ( MAX ) = 24 k ?
? 2 . 4 V – V OUT ?
HigherinputvoltageapplicationsinwhichlargeMOSFETs
are being driven at high frequencies may cause the maxi-
mum junction temperature rating for the IC to be exceeded.
The system supply current is normally dominated by the
gate charge current. Additional external loading of the
INTV CC also needs to be taken into account for the power
dissipation calculations.
The absolute maximum rating for the INTV CC Pin is 50mA.
To prevent maximum junction temperature from being
exceeded, the input supply current must be checked
operating in continuous mode at maximum V IN .
Topside MOSFET Driver Supply (C B , D B )
External bootstrap capacitors, C B , connected to the BOOST
pins supply the gate drive voltages for the topside MOSFETs.
Capacitor C B in the Functional Diagram is charged though
external diode D B from INTV CC when the SW pin is low.
When one of the topside MOSFETs is to be turned on, the
driver places the C B voltage across the gate source of the
desired MOSFET. This enhances the MOSFET and turns on
the topside switch. The switch node voltage, SW, rises to
V IN and the BOOST pin follows. With the topside MOSFET
on, the boost voltage is above the input supply: V BOOST
= V IN + V INTVCC . The value of the boost capacitor, C B ,
needs to be 100 times that of the total input capacitance
of the topside MOSFET(s). The reverse breakdown of the
external Schottky diode must be greater than V IN(MAX) .
When adjusting the gate-drive level, the ?nal arbiter is the
total input current for the regulator. If a change is made
and the input current decreases, then the ef?ciency has
improved. If there is no change in input current, then there
where R1 and R2 are de?ned in Figure 1.
SENSE + /SENSE – Pins
The common mode input range of the current comparator
sense pins is from 0V to (1.1)INTV CC . Continuous linear
operation is guaranteed throughout this range allowing
output voltage setting from 0.8V to 7.7V. A differential
NPN input stage is biased with internal resistors from an
internal 2.4V source as shown in the Functional Diagram.
This requires that current either be sourced or sunk from
the SENSE pins depending on the output voltage. If the
output voltage is below 2.4V current will ?ow out of both
SENSE pins to the main output. The output can be easily
preloaded by the V OUT resistive divider to compensate
for the current comparator’s negative input bias current.
The maximum current ?owing out of each pair of SENSE
pins is:
I SENSE+ + I SENSE– = (2.4V – V OUT )/24k
Since V OSENSE is servoed to the 0.8V reference voltage,
we can choose R1 in Figure 1 to have a maximum value
to absorb this current.
? 0 . 8 V ?
?
for V OUT < 2.4V
Regulating an output voltage of 1.8V, the maximum value
of R1 should be 32k. Note that for an output voltage above
2.4V, R1 has no maximum value necessary to absorb the
sense currents; however, R1 is still bounded by the V OSENSE
feedback current.
is no change in ef?ciency.
RUN and Soft-Start
Output Voltage
The output voltages are each set by an external feedback
resistive divider carefully placed across the output capaci-
tor. The resultant feedback signal is compared with the
internal precision 0.800V voltage reference by the error
ampli?er. The output voltage is given by the equation:
The LTC3828 RUN pins shut down their respective chan-
nels independently. The LTC3828 is put in a low quiescent
current state (I Q < 30μA) if both RUN pin voltages are
below 1V. TRCKSS pins are actively pulled to ground in
this shutdown state. Once the RUN pin voltages are above
1.5V, the respective channel of the LTC3828 is powered
3828fc
19
相关PDF资料
PDF描述
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
LTC3833EFE#PBF IC REG CTRLR BUCK PWM CM 20TSSOP
相关代理商/技术参数
参数描述
LTC3829EFE#PBF 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® 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
LTC3829EFE#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
LTC3829EUHF#PBF 功能描述:IC REG CTRLR BUCK PWM CM 38-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)
LTC3829EUHF#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 38-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
LTC3829IFE#PBF 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