參數(shù)資料
型號(hào): LTC1709-9
廠商: Linear Technology Corporation
英文描述: CHOKE COIL 33UH 260MA SMD
中文描述: 2相,5位VID,電流模式,高效率同步降壓型開關(guān)穩(wěn)壓器
文件頁(yè)數(shù): 11/28頁(yè)
文件大?。?/td> 319K
代理商: LTC1709-9
11
LTC1709-7
OPERATIOU
Frequency Synchronization
The phase-locked loop allows the internal oscillator to be
synchronized to an external source via the PLLIN pin. The
output of the phase detector at the PLLFLTR pin is also the
DC frequency control input of the oscillator that operates
over a 140kHz to 310kHz range corresponding to a DC
voltage input from 0V to 2.4V. When locked, the PLL aligns
the turn on of the top MOSFET to the rising edge of the
synchronizing signal. When PLLIN is left open, the PLLFLTR
pin goes low, forcing the oscillator to minimum frequency.
Input capacitance ESR requirements and efficiency losses
are substantially reduced because the peak current drawn
from the input capacitor is effectively divided by two and
power loss is proportional to the RMS current squared. A
two stage, single output voltage implementation can
reduce input path power loss by 75% and radically reduce
the required RMS current rating of the input capacitor(s).
(Refer to Functional Diagram)
INTV
CC
/EXTV
CC
Power
Power for the top and bottom MOSFET drivers and most
of the IC circuitry is derived from INTV
CC
. When the
EXTV
CC
pin is left open, an internal 5V low dropout
regulator supplies INTV
CC
power. If the EXTV
CC
pin is
taken above 4.7V, the 5V regulator is turned off and an
internal switch is turned on connecting EXTV
CC
to INTV
CC
.
This allows the INTV
CC
power to be derived from a high
efficiency external source such as the output of the regu-
lator itself or a secondary winding, as described in the
Applications Information section. An external Schottky
diode can be used to minimize the voltage drop from
EXTV
CC
to INTV
CC
in applications requiring greater than
the specified INTV
CC
current.
Voltages up to 7V can be
applied to EXTV
CC
for additional gate drive capability.
Differential Amplifier
This amplifier provides true differential output voltage
sensing. Sensing both V
OUT+
and V
OUT–
benefits regula-
tion in high current applications and/or applications
having electrical interconnection losses. The amplifier is
not capable of sinking current and therefore must be
resistively loaded to do so.
Output Overvoltage Protection
An overvoltage comparator, OV, guards against transient
overshoots (>7.5%) as well as other more serious condi-
tions that may overvoltage the output. In this case, the top
MOSFET is turned off and the bottom MOSFET is turned on
until the overvoltage condition is cleared.
Power Good (PGOOD)
The PGOOD pin is connected to the drain of an internal
MOSFET. The MOSFET turns on when the output voltage
is not within
±
7.5% of its nominal output level as deter-
mined by the feedback divider. When the output is within
±
7.5% of its nominal value, the MOSFET is turned off
within 10
μ
s and the PGOOD pin should be pulled up by an
external resistor to a source of up to 7V.
Short-Circuit Detection
The RUN/SS capacitor is used initially to limit the inrush
current from the input power source. Once the control-
lers have been given time, as determined by the capacitor
on the RUN/SS pin, to charge up the output capacitors
and provide full-load current, the RUN/SS capacitor is
then used as a short-circuit timeout circuit. If the output
voltage falls to less than 70% of its nominal output
voltage the RUN/SS capacitor begins discharging as-
suming that the output is in a severe overcurrent and/or
short-circuit condition. If the condition lasts for a long
enough period as determined by the size of the RUN/SS
capacitor, the controller will be shut down until the
RUN/SS pin voltage is recycled. This built-in latchoff can
be overidden by providing a current >5
μ
A at a compli-
ance of 5V to the RUN/SS pin. This current shortens the
soft-start period but also prevents net discharge of the
RUN/SS capacitor during a severe overcurrent and/or
short-circuit condition. Foldback current limiting is acti-
vated when the output voltage falls below 70% of its
nominal level whether or not the short-circuit latchoff
circuit is enabled.
相關(guān)PDF資料
PDF描述
LTC1709EG CHOKE COIL 6.8UH 620MA SMD
LTC1709EG-7 RADIATION HARDENED HIGH EFFICIENCY, 5 AMP SWITCHING REGULATORS
LTC1726ES8-2.5 Triple Supply Monitor and uP Supervisor with Adjustable Reset and Watchdog Timer
LTC1726EMS8-2.5 Triple Supply Monitor and uP Supervisor with Adjustable Reset and Watchdog Timer
LTC1726 Triple Supply Monitor and uP Supervisor with Adjustable Reset and Watchdog Timer
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC1709EG 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1709EG#PBF 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,000 系列:- PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤 包裝:帶卷 (TR)
LTC1709EG#TR 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數(shù):1 頻率 - 最大:1MHz 占空比:95% 電源電壓:2.8 V ~ 5.5 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 125°C 封裝/外殼:6-WDFN 裸露焊盤 包裝:帶卷 (TR) 配用:LM1771EVAL-ND - BOARD EVALUATION LM1771 其它名稱:LM1771SSDX
LTC1709EG#TRPBF 功能描述:IC REG CTRLR BUCK PWM CM 36-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:- 標(biāo)準(zhǔn)包裝:4,000 系列:- PWM 型:電壓模式 輸出數(shù):1 頻率 - 最大:1.5MHz 占空比:66.7% 電源電壓:4.75 V ~ 5.25 V 降壓:是 升壓:無(wú) 回掃:無(wú) 反相:無(wú) 倍增器:無(wú) 除法器:無(wú) Cuk:無(wú) 隔離:無(wú) 工作溫度:-40°C ~ 85°C 封裝/外殼:40-VFQFN 裸露焊盤 包裝:帶卷 (TR)
LTC1709EG7 制造商:Linear Technology 功能描述: