- 您現(xiàn)在的位置：買賣IC網 > PDF目錄44992 > LTC3707IGN-SYNC (LINEAR TECHNOLOGY CORP) 3 A SWITCHING CONTROLLER, 360 kHz SWITCHING FREQ-MAX, PDSO28 PDF資料下載
參數資料
| 型號： | LTC3707IGN-SYNC |
| 廠商： | LINEAR TECHNOLOGY CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 3 A SWITCHING CONTROLLER, 360 kHz SWITCHING FREQ-MAX, PDSO28 |
| 封裝： | 0.150 INCH, PLASTIC, SSOP-28 |
| 文件頁數： | 9/32頁 |
| 文件大?。?/td> | 403K |
| 代理商： | LTC3707IGN-SYNC |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁當前第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁
LTC3707-SYNC
17
3707sfa
INTVCC Regulator
An internal P-channel low dropout regulator produces 5V
at the INTVCC pin from the VIN supply pin. INTVCC powers
the drivers and internal circuitry within the LTC3707-SYNC.
The INTVCC pin regulator can supply a peak current of
50mA and must be bypassed to ground with a minimum
of 4.7μF tantalum, 10μF special polymer, or low ESR type
electrolytic capacitor. A 1μF ceramic capacitor placed di-
rectly adjacent to the INTVCC and PGND IC pins is highly
recommended. Good bypassing is necessary to supply
the high transient currents required by the MOSFET gate
drivers and to prevent interaction between channels.
Higher input voltage applications in which large MOSFETs
are being driven at high frequencies may cause the
maximum junction temperature rating for the IC to be
exceeded.Thesystemsupplycurrentisnormallydominated
by the gate charge current. Additional external loading of
the INTVCC and 3.3V linear regulators also needs to be
taken into account for the power dissipation calculations.
The total INTVCC current can be supplied by either the
5V internal linear regulator or by the EXTVCC input pin.
When the voltage applied to the EXTVCC pin is less than
4.7V, all of the INTVCC current is supplied by the internal
5V linear regulator. Power dissipation for the IC in this
case is highest: (VIN)(IINTVCC), and overall efciency is
lowered. The gate charge current is dependent on operating
frequency as discussed in the Efciency Considerations
section. The junction temperature can be estimated by
using the equations given in Note 2 of the Electrical
Characteristics. For example, the IC VIN current is limited
to less than 24mA from a 24V supply when not using the
EXTVCC pin as follows:
TJ = 70°C + (24mA)(24V)(95°C/W) = 125°C
Use of the EXTVCC input pin reduces the junction
temperature to:
TJ = 70°C + (24mA)(5V)(95°C/W) = 81°C
Dissipation should be calculated to also include any added
current drawn from the internal 3.3V linear regulator.
To prevent maximum junction temperature from being
exceeded, the input supply current must be checked
operating in continuous mode at maximum VIN.
APPLICATIONS INFORMATION
EXTVCC Connection
The IC contains an internal P-channel MOSFET switch
connected between the EXTVCC and INTVCC pins. When
the voltage applied to EXTVCC rises above 4.7V, the internal
regulator is turned off and the switch closes, connecting
the EXTVCC pin to the INTVCC pin thereby supplying internal
power. The switch remains closed as long as the voltage
applied to EXTVCC remains above 4.5V. This allows the
MOSFET driver and control power to be derived from the
output during normal operation (4.7V < VOUT < 7V) and
from the internal regulator when the output is out of regu-
lation (start-up, short-circuit). If more current is required
through the EXTVCC switch than is specied, an external
Schottky diode can be added between the EXTVCC and
INTVCC pins. Do not apply greater than 7V to the EXTVCC
pin and ensure that EXTVCC ≤ VIN.
Signicant efciency gains can be realized by powering
INTVCC from the output, since the VIN current resulting
from the driver and control currents will be scaled by a
factor of (Duty Cycle)/(Efciency). For 5V regulators this
supply means connecting the EXTVCC pin directly to VOUT.
However, for 3.3V and other lower voltage regulators,
additional circuitry is required to derive INTVCC power
from the output.
The following list summarizes the four possible connec-
tions for EXTVCC:
1. EXTVCC Left Open (or Grounded). This will cause INTVCC
to be powered from the internal 5V regulator resulting in an
efciency penalty of up to 10% at high input voltages.
2. EXTVCC Connected directly to VOUT. This is the normal
connection for a 5V regulator and provides the highest
efciency.
3. EXTVCC Connected to an External supply. If an external
supply is available in the 5V to 7V range, it may be used to
power EXTVCC providing it is compatible with the MOSFET
gate drive requirements.
4. EXTVCCConnectedtoanOutput-DerivedBoostNetwork.
For 3.3V and other low voltage regulators, efciency
gains can still be realized by connecting EXTVCC to an
output-derived voltage that has been boosted to greater
相關PDF資料 |
PDF描述 |
|---|---|
| LTC3728IUH | 3 A DUAL SWITCHING CONTROLLER, 590 kHz SWITCHING FREQ-MAX, PQCC32 |
| LTC3728IG | 3 A DUAL SWITCHING CONTROLLER, 590 kHz SWITCHING FREQ-MAX, PDSO28 |
| LTC3728LIUH-1#TR | 3 A DUAL SWITCHING CONTROLLER, 590 kHz SWITCHING FREQ-MAX, PQCC32 |
| LTC3728LIGN-1 | 3 A DUAL SWITCHING CONTROLLER, 590 kHz SWITCHING FREQ-MAX, PDSO28 |
| LTC3731HUH#TRPBF | 5 A SWITCHING CONTROLLER, 750 kHz SWITCHING FREQ-MAX, PQCC32 |
相關代理商/技術參數 |
參數描述 |
|---|---|
| LTC3707IGN-SYNC#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 標準包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數: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 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 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 |
| LTC3707IGN-SYNC#TRPBF | 功能描述:IC REG CTRLR BUCK PWM CM 28-SSOP RoHS:是 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 標準包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數: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 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 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 |
| LTC3708EUH | 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 標準包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數: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 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 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 |
| LTC3708EUH#PBF | 功能描述:IC REG CTRLR BUCK PWM CM 32-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® 特色產品:LM3753/54 Scalable 2-Phase Synchronous Buck Controllers 標準包裝:1 系列:PowerWise® PWM 型:電壓模式 輸出數:1 頻率 - 最大:1MHz 占空比:81% 電源電壓:4.5 V ~ 18 V 降壓:是 升壓:無 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 工作溫度:-5°C ~ 125°C 封裝/外殼:32-WFQFN 裸露焊盤 包裝:Digi-Reel® 產品目錄頁面:1303 (CN2011-ZH PDF) 其它名稱:LM3754SQDKR |
| LTC3708EUH#TR | 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN RoHS:否 類別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:PolyPhase® 標準包裝:4,500 系列:PowerWise® PWM 型:控制器 輸出數: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 回掃:無 反相:無 倍增器:無 除法器:無 Cuk:無 隔離:無 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 |
發(fā)布緊急采購，3分鐘左右您將得到回復。