參數(shù)資料
型號(hào)： LTC3860IUH#PBF
廠商： LINEAR TECHNOLOGY CORP
元件分類： 穩(wěn)壓器
英文描述： DUAL SWITCHING CONTROLLER, 1250 kHz SWITCHING FREQ-MAX, PQCC32
封裝： 5 X 5 MM, LEAD FREE, PLASTIC, MO-220WHHD, QFN-32
文件頁(yè)數(shù)： 4/36頁(yè)
文件大?。?/td> 436K
代理商： LTC3860IUH#PBF
LTC3860
12
3860fc
Certain applications can result in the start-up of the
converter into a non-zero load voltage, where residual
charge is stored on the output capacitor at the onset of
converter switching. In order to prevent the output from
discharging under these conditions, the bottom MOSFET
is disabled until soft-start is complete. However, the bot-
tom MOSFET will be turned on for 20ns every 8 cycles
to allow the driver IC to recharge its topside gate drive
capacitor.
Soft-Start and Tracking Using TRACK/SS Pin
The user can connect an external capacitor greater than
10nF to the TRACK/SS pin for the relevant channel to
increase the soft-start ramp time beyond the internally set
default. The TRACK/SS pin represents a noninverting input
to the error amplier and behaves identically to the internal
ramp described in the previous section. An internal 2.5μA
current source charges the capacitor, creating a voltage
ramp on the TRACK/SS pin. As the TRACK/SS pin voltage
rises from 0V to 0.6V, the output voltage rises smoothly
from 0V to its nal value in:
C
SS 0.6V
2.5A
seconds
Alternatively, the TRACK/SS pin can be used to force the
start-up of VOUT to track the voltage of another supply.
Typically this requires connecting the TRACK/SS pin to
an external divider from the other supply to ground (see
Applications Information). It is only possible to track
another supply that is slower than the internal soft-start
ramp. The TRACK/SS pin also has an internal open-drain
NMOS pull-down transistor that turns on to reset the
TRACK/SS voltage when the channel is shut down (RUN
= 0V or VCC < UVLO threshold) or during an OC fault
condition.
In multiphase operation, one master error amplier is
used to control all of the PWM comparators. The FB pins
for the unused error ampliers are connected to VCC in
order to three-state these amplier outputs, and the COMP
pins are connected together. The TRACK/SS pins should
also be connected together so that the slave phases can
detect when soft-start is complete and enable the bottom
MOSFET.
Frequency Selection and the Phase-Locked Loop (PLL)
The selection of the switching frequency is a trade-off
between efciency, transient response and component
size. High frequency operation reduces the size of the
inductor and output capacitor as well as increasing the
maximum practical control loop bandwidth. However,
efciency is generally lower due to increased transition
and switching losses.
The LTC3860’s switching frequency can be set in three
ways: using an external resistor to linearly program the
frequency, synchronizing to an external clock, or simply
selecting one of two xed frequencies (400kHz and
600kHz). Table 1 highlights these modes.
Table 1. Frequency Selection
CLKIN PIN
FREQ PIN
FREQUENCY
Clocked
RFREQ to GND
250kHz to 1.25MHz
High
RFREQ to GND
250kHz to 1.25MHz
Low
400kHz
Low
High
600kHz
No external PLL lter is required to synchronize the
LTC3860 to an external clock. Applying an external clock
signal to the CLKIN pin will automatically enable the PLL
with internal lter.
Constant frequency operation brings with it a number of
benets: inductor and capacitor values can be chosen
for a precise operating frequency and the feedback loop
can be similarly tightly specied. Noise generated by the
circuit will always be at known frequencies.
Using the CLKOUT and PHSMD Pins in
Multiphase Applications
The LTC3860 features CLKOUT and PHSMD pins that al-
low multiple LTC3860 ICs to be daisychained together in
multiphase applications. The clock output signal on the
CLKOUT pin can be used to synchronize additional ICs in
a 3-, 4-, 6- or 12-phase power supply solution feeding a
single high current output, or even several outputs from
the same input supply.
The PHSMD pin is used to adjust the phase relationship
between channel 1 and channel 2, as well as the phase
OPERATION (Refer to Functional Diagram)
相關(guān)PDF資料
PDF描述
LTC3862HUH#TRPBF DUAL SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, QCC24
LTC3862IFE#PBF DUAL SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO24
LTC3862HFE#PBF DUAL SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO24
LTC3862EGN#TRPBF DUAL SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO24
LTC3862IUH#PBF DUAL SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, QCC24
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC3861EUH-1#PBF 制造商:Linear Technology 功能描述:IC REG CTRLR BUCK PWM VM 32-QFN 制造商:Linear Technology 功能描述:BUCK CNTRL DUAL 12PH 2.25MHZ 32QFN 制造商:Linear Technology 功能描述:BUCK, CNTRL, DUAL, 12PH, 2.25MHZ, 32QFN 制造商:Linear Technology 功能描述:PWM CONTROLLER, BUCK, 2.25MHZ, 24V, QFN-32, Input Voltage:24V, Output Voltage:5.5V, Output Current:60A, Supply Voltage Min:3V, Supply Voltage Max:5.5V, Digital IC Case Style:QFN, No. of Pins:32, Frequency:2.25MHz , RoHS Compliant: Yes 制造商:Linear Technology 功能描述:DP-SWREG/Controller, Dual-Phase/Dual-Channel Step-Down Voltage Mode Controller w
LTC3861EUH-1#TRPBF 制造商:Linear Technology 功能描述:IC REG CTRLR BUCK PWM VM 32-QFN
LTC3861EUHE#PBF 功能描述:IC REG CTRLR BUCK PWM VM 36-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 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
LTC3861EUHE#TRPBF 功能描述:IC REG CTRLR BUCK PWM VM 36-QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 標(biāo)準(zhǔn)包裝:2,500 系列:- PWM 型:電流模式 輸出數(shù):1 頻率 - 最大:500kHz 占空比:96% 電源電壓:4 V ~ 36 V 降壓:無(wú) 升壓:是 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:24-WQFN 裸露焊盤 包裝:帶卷 (TR)
LTC3861IUH-1#PBF 制造商:Linear Technology 功能描述:DC DC Cntrlr Dual-OUT Sync Step Down 3V to 24V Input 32-Pin QFN EP 制造商:Linear Technology 功能描述:IC REG CTRLR BUCK PWM VM 32-QFN 制造商:Linear Technology 功能描述:BUCK CNTRL DUAL 12PH 2.25MHZ 32QFN 制造商:Linear Technology 功能描述:BUCK, CNTRL, DUAL, 12PH, 2.25MHZ, 32QFN 制造商:Linear Technology 功能描述:DP-SWREG/Controller, Dual-Phase/Dual-Channel Step-Down Voltage Mode Controller w 制造商:Linear Technology 功能描述:PWM CONTROLLER, BUCK, 2.25MHZ, 24V, QFN-32, Input Voltage:24V, Output Voltage:5.5V, Output Current:60A, Supply Voltage Min:3V, Supply Voltage Max:5.5V, Digital IC Case Style:QFN, No. of Pins:32, Frequency:2.25MHz , RoHS Compliant: Yes
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*