参数资料
型号: LTC3809EMS
厂商: LINEAR TECHNOLOGY CORP
元件分类: 稳压器
英文描述: 1 A SWITCHING CONTROLLER, 825 kHz SWITCHING FREQ-MAX, PDSO10
封装: PLASTIC, MSOP-10
文件页数: 21/24页
文件大小: 266K
代理商: LTC3809EMS
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LTC3809
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PLLLPF (Pin 1): Frequency Set/PLL Lowpass Filter. When
synchronizing to an external clock, this pin serves as the
low pass filter point for the phase-locked loop. Normally,
a series RC is connected between this pin and ground.
When not synchronizing to an external clock, this pin serves
as the frequency select input. Tying this pin to GND selects
300kHz operation; tying this pin to VIN selects 750kHz
operation. Floating this pin selects 550kHz operation.
Connect a 2.2nF capacitor between this pin and GND, and
a 1000pF capacitor between this pin and the SYNC/MODE
when using spread spectrum modulation operation.
SYNC/MODE (Pin 2): This pin performs four functions: 1)
auxiliary winding feedback input, 2) external clock syn-
chronization input for phase-locked loop, 3) Burst Mode,
pulse skipping or forced continuous mode select, and 4)
enable spread spectrum modulation operation in pulse
skipping mode. Applying a clock with frequency between
250kHz to 750kHz causes the internal oscillator to phase-
lock to the external clock and disables Burst Mode opera-
tion but allows pulse skipping at low load currents.
To select Burst Mode operation at light loads, tie this pin
to VIN. Grounding this pin selects forced continuous
operation, which allows the inductor current to reverse.
Tying this pin to VFB selects pulse skipping mode. In these
cases, the frequency of the internal oscillator is set by the
voltage on the PLLLPF pin. Tying to a voltage between
1.35V to VIN – 0.5V enables spread spectrum modulation
operation. In this case, an internal 2.6
A pull-down cur-
rent source helps to set the voltage at this pin by tying a
resistor with appropriate value between this pin and VIN.
Do not leave this pin floating.
VFB (Pin 3): Feedback Pin. This pin receives the remotely
sensed feedback voltage for the controller from an exter-
nal resistor divider across the output.
ITH (Pin 4): Current Threshold and Error Amplifier Com-
pensation Point. Nominal operating range on this pin is
from 0.7V to 2V. The voltage on this pin determines the
threshold of the main current comparator.
RUN (Pin 5): Run Control Input. Forcing this pin below
1.1V shuts down the chip. Driving this pin to VIN or
releasing this pin enables the chip to start-up with the
internal soft-start.
IPRG (Pin 6): Three-State Pin to Select Maximum Peak
Sense Voltage Threshold. This pin selects the maximum
allowed voltage drop between the VIN and SW pins (i.e.,
the maximum allowed drop across the external P-channel
MOSFET). Tie to VIN, GND or float to select 204mV, 85mV
or 125mV respectively.
BG (Pin 7): Bottom (NMOS) Gate Drive Output. This pin
drives the gate of the external N-channel MOSFET. This pin
has an output swing from PGND to VIN.
TG (Pin 8): Top (PMOS) Gate Drive Output. This pin drives
the gate of the external P-channel MOSFET. This pin has an
output swing from PGND to VIN.
VIN (Pin 9): Chip Signal Power Supply. This pin powers the
entire chip, the gate drivers and serves as the positive
input to the differential current comparator.
SW (Pin 10): Switch Node Connection to Inductor. This
pin is also the negative input to the differential current
comparator and an input to the reverse current compara-
tor. Normally this pin is connected to the drain of the
external P-channel MOSFET, the drain of the external
N-channel MOSFET and the inductor.
GND (Pin 11): Exposed Pad. The Exposed Pad is ground
and must be soldered to the PCB ground for electrical
contact and optimum thermal performance.
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相关代理商/技术参数
参数描述
LTC3809EMSE 功能描述:IC REG CTRLR BUCK PWM CM 10-MSOP 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)
LTC3809EMSE#PBF 功能描述:IC REG CTRLR BUCK PWM CM 10-MSOP 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)
LTC3809EMSE#TR 功能描述:IC REG CTRLR BUCK PWM CM 10-MSOP 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)
LTC3809EMSE#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 10-MSOP 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)
LTC3809EMSE-1 功能描述:IC REG CTRLR BUCK PWM CM 10-MSOP 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)