參數(shù)資料
型號(hào)： LTC3765IMSE#TRPBF
廠商： LINEAR TECHNOLOGY CORP
元件分類： 電源管理
英文描述： 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO16
封裝： LEAD FREE, PLASTIC, MSOP-16
文件頁(yè)數(shù)： 24/24頁(yè)
文件大?。?/td> 265K
代理商： LTC3765IMSE#TRPBF
LTC3765
9
3765f
OPERATION
TheLTC3765isaforwardconverterstart-upcontrollerand
gate driver for use in a single-switch forward converter
with active clamp reset. When connected through a pulse
transformer to the LTC3766 secondary-side synchronous
forward controller, it forms a highly efficient forward con-
verter with secondary-side regulation, galvanic isolation
between input and output, and synchronous rectification.
TheLTC3765andLTC3766biasvoltagesaregeneratedfrom
a proprietary self-starting architecture which eliminates
the need for an additional bias supply.
Linear Regulator
The LTC3765 features an external series pass linear
regulator controller that eliminates the long start-up time
associated with a conventional trickle charger. The NDRV
pin regulates the gate of an external NMOS transistor to
ramp up the VCC supply with a well controlled 35s ramp
time to the 8.5V regulation point. For low input supply
voltage applications where the threshold of the external
NMOS transistor limits the VCC voltage, an internal charge
pump boosts NDRV to a voltage higher than VIN so that
the external NMOS can be fully enhanced.
Self-Starting Start-up
When power is first applied and when the RUN pin and
VCC have satisfied their respective start-up requirements,
the LTC3765 begins open-loop operation using its own
internal oscillator. Power is supplied to the secondary by
switching the gate drivers with a gradually increasing duty
cycle from 0% to 70% as controlled by the rate of rise of
thevoltageontheSSFLTpin.Apeakchargecircuitpowered
from an auxiliary winding off of the main transformer al-
lows the LTC3766 to begin operation even for small duty
cycles. When the LTC3766 has adequate voltage to satisfy
its start-up requirements, it provides duty cycle informa-
tion through the pulse transformer as shown in Figure 2.
The LTC3765 detects this signal and transfers control of
the gate drivers to the LTC3766. The LTC3765 turns off
the linear regulator and, through an on-chip rectifier, also
extracts power from this signal.
Gate Drive Encoding
The LTC3766 secondary-side forward controller sends a
pulse-encoded signal through a small pulse transformer
and series DC restore capacitor to the IN+ and IN– pins of
the LTC3765. After a brief start-up sequence to establish a
communication lock between the two parts, the LTC3765
extracts clock and duty cycle information from the signal
and uses it to control the PG and AG gate driver outputs.
Figure 2 shows how the LTC3766 drives the pulse trans-
former in a complementary fashion, with a duty cycle of
79%. At the appropriate time during the positive cycle,
the LTC3766 applies a short (150ns) zero voltage pulse
across the pulse transformer, indicating the end of the
PG “on” time.
DUTY CYCLE = 15%
DUTY CYCLE = 0%
150ns
3765 F02
1 CLK PER
VIN+ – VIN–
Figure 2. Gate Drive Multiplexing Scheme
Gate Drivers and Delay Adjustment
The active clamp gate driver (AG) and the primary switch
gate driver (PG) are “in-phase,” with a programmable
overlap time set by the DELAY pin. In an active clamp
forward converter topology, the delay time between the
active clamp PMOS turn-off and the primary switch NMOS
turn-oniscriticalforoptimizingefficiency.Whentheactive
clamp is on, the drain of the primary NMOS, or primary
switch node (SWP), is driven to a voltage of approximately
VIN/(1 – Duty Cycle) by the main transformer. When the
active clamp turns off, the current in the magnetizing
inductance of the transformer ramps this voltage linearly
down to VIN. Transitional power loss in the primary switch
is minimized by turning it on when this voltage is at a
minimum.
相關(guān)PDF資料
PDF描述
LTC3766IGN#PBF SWITCHING CONTROLLER, 316 kHz SWITCHING FREQ-MAX, PDSO28
LTC3766HGN#TRPBF SWITCHING CONTROLLER, 316 kHz SWITCHING FREQ-MAX, PDSO28
LTC3766HUFD#TRPBF SWITCHING CONTROLLER, 316 kHz SWITCHING FREQ-MAX, PQCC28
LTC3766IUFD#TRPBF SWITCHING CONTROLLER, 316 kHz SWITCHING FREQ-MAX, PQCC28
LTC3766MPUFD#TRPBF SWITCHING CONTROLLER, 316 kHz SWITCHING FREQ-MAX, PQCC28
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
LTC3765MPMSE#PBF 功能描述:IC CONTROLLER GATE DR 16MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電源控制器，監(jiān)視器 系列:Direct Flux Limit™ 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 應(yīng)用:多相控制器 輸入電壓:- 電源電壓:9 V ~ 14 V 電流 - 電源:- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP（5x5） 包裝:帶卷 (TR)
LTC3765MPMSE#TRPBF 功能描述:IC CONTROLLER GATE DR 16MSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電源控制器，監(jiān)視器 系列:Direct Flux Limit™ 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 應(yīng)用:多相控制器 輸入電壓:- 電源電壓:9 V ~ 14 V 電流 - 電源:- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP（5x5） 包裝:帶卷 (TR)
LTC3766EGN#PBF 功能描述:IC CONTROLLER SYNCH 28-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電源控制器，監(jiān)視器 系列:Direct Flux Limit™, PolyPhase® 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 應(yīng)用:多相控制器 輸入電壓:- 電源電壓:9 V ~ 14 V 電流 - 電源:- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP（5x5） 包裝:帶卷 (TR)
LTC3766EGN#TRPBF 功能描述:IC CONTROLLER SYNCH 28SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 電源控制器，監(jiān)視器 系列:Direct Flux Limit™, PolyPhase® 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 應(yīng)用:多相控制器 輸入電壓:- 電源電壓:9 V ~ 14 V 電流 - 電源:- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP（5x5） 包裝:帶卷 (TR)
LTC3766EUFD#PBF 功能描述:IC CONTROLLER SYNCH 28QFN RoHS:是 類別:集成電路 (IC) >> PMIC - 電源控制器，監(jiān)視器 系列:Direct Flux Limit™, PolyPhase® 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 應(yīng)用:多相控制器 輸入電壓:- 電源電壓:9 V ~ 14 V 電流 - 電源:- 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:40-WFQFN 裸露焊盤 供應(yīng)商設(shè)備封裝:40-TQFN-EP（5x5） 包裝:帶卷 (TR)
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

*
*
*