- 您現(xiàn)在的位置：買(mǎi)賣(mài)IC網(wǎng) > PDF目錄384524 > ISL6269A (Intersil Corporation) High-Performance Notebook PWM Controller(高性能筆記本PWM控制器) PDF資料下載
參數(shù)資料
| 型號(hào)： | ISL6269A |
| 廠商： | Intersil Corporation |
| 英文描述： | High-Performance Notebook PWM Controller(高性能筆記本PWM控制器) |
| 中文描述： | 高性能筆記本PWM控制器（高性能筆記本的PWM控制器） |
| 文件頁(yè)數(shù)： | 8/14頁(yè) |
| 文件大?。?/td> | 313K |
| 代理商： | ISL6269A |
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)當(dāng)前第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)
8
FN9253.2
May 30, 2007
The PGOOD pin indicates when the converter is capable of
supplying regulated voltage. The PGOOD pin is an
undefined impedance if
V
VCC
has not reached the rising
POR threshold
V
VCC_THR
, or if
V
VCC
is below the falling POR
threshold
V
VCC_THF
. The ISL6269A features a unique fault-
identification capability that can drastically reduce trouble-
shooting time and effort. The pull-down resistance of the
PGOOD pin corresponds to the fault status of the controller.
During soft-start or if an undervoltage fault occurs, the
PGOOD pulldown resistance is 95
Ω
, or 30
Ω
for an
overcurrent fault, or 60
Ω
for an overvoltage fault.
MOSFET Gate-Drive Outputs LG and UG
The ISL6269A has internal gate-drivers for the high-side and
low-side N-Channel MOSFETs. The LG gate-driver is
optimized for low duty-cycle applications where the low-side
MOSFET conduction losses are dominant, requiring a low
r
DS(ON)
MOSFET. The LG pulldown resistance is small in
order to clamp the gate of the MOSFET below the V
GS(th)
at
turnoff. The current transient through the gate at turnoff can
be considerable because the switching charge of a low
r
DS(ON)
MOSFET can be large. Adaptive shoot-through
protection prevents a gate-driver output from turning on until
the opposite gate-driver output has fallen below
approximately 1V. The dead-time shown in Figure 5. is
extended by the additional period that the falling gate voltage
stays above the 1V threshold. The high-side gate-driver
output voltage is measured across the UG and PHASE pins
while the low-side gate-driver output voltage is measured
across the LG and PGND pins. The power for the LG
gate-driver is sourced directly from the PVCC pin. The power
for the UG gate-driver is sourced from a “boot” capacitor
connected across the BOOT and PHASE pins. The boot
capacitor is charged from a 5V bias supply through a “boot
diode” each time the low-side MOSFET turns on, pulling the
PHASE pin low. The ISL6269A has an integrated boot diode
connected from the PVCC pin to the BOOT pin.
Diode Emulation
The ISL6269A normally operates in continuous-conduction-
mode (CCM), minimizing conduction losses by forcing the
low-side MOSFET to operate as a synchronous rectifier. An
improvement in light-load efficiency is achieved by allowing
the converter to operate in diode-emulation-mode (DEM),
where the low-side MOSFET behaves as a smart-diode,
forcing the device to block negative inductor current flow.
The ISL6269A can be configured to operate in DEM by
setting the FCCM pin low. Setting the FCCM pin high will
disable DEM.
Positive-going inductor current flows from either the source
of the high-side MOSFET, or the drain of the low-side
MOSFET. Negative-going inductor current usually flows into
the drain of the low-side MOSFET. When the low-side
MOSFET conducts positive inductor current, the phase
voltage will be negative with respect to the GND and PGND
pins. Conversely, when the low-side MOSFET conducts
negative inductor current, the phase voltage will be positive
with respect to the GND and PGND pins. Negative inductor
current occurs when the output load current is less than
the inductor ripple current. Sinking negative inductor current
through the low-side MOSFET lowers efficiency through
unnecessary conduction losses. Efficiency can be further
improved with a reduction of unnecessary switching losses
by reducing the PWM frequency. It is characteristic of the R
3
architecture for the PWM frequency to decrease while in
diode emulation. The extent of the frequency reduction is
proportional to the reduction of load current. Upon entering
DEM, the PWM frequency makes an initial step-reduction
because of a 33% step-increase of the window voltage V
W
.
With FCCM pulled low, the converter will automatically enter
DEM after the PHASE pin has detected positive voltage,
TABLE 1. PGOOD PULL-DOWN RESISTANCE
CONDITION
PGOOD RESISTANCE
VCC Below POR
Undefined
Soft Start or Undervoltage
95
Ω
Overvoltage
60
Ω
Overcurrent
30
Ω
EN
VCC and PVCC
VOUT
PGOOD
1.5ms
2.75ms
FIGURE 4. SOFT-START SEQUENCE
FIGURE 5. LG AND UG DEAD-TIME
UG
LG
50%
50%
t
LGFUGR
t
UGFLGR
ISL6269A
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ISL6271ACRZ | Integrated XScale Regulator |
| ISL6271ACRZ-T | Integrated XScale Regulator |
| ISL6271A | Integrated XScale Regulator |
| ISL6271ACR | Integrated XScale Regulator |
| ISL6271ACR-T | Integrated XScale Regulator |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ISL6269ACRZ | 功能描述:IC REG CTRLR BUCK PWM 16-QFN RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:Robust Ripple Regulator™ (R³) 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:- PWM 型:電流模式 輸出數(shù):1 頻率 - 最大:275kHz 占空比:50% 電源電壓:18 V ~ 110 V 降壓:無(wú) 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:是 工作溫度:-40°C ~ 85°C 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 包裝:帶卷 (TR) |
| ISL6269ACRZ-T | 功能描述:IC REG CTRLR BUCK PWM 16-QFN RoHS:是 類(lèi)別:集成電路 (IC) >> PMIC - 穩(wěn)壓器 - DC DC 切換控制器 系列:Robust Ripple Regulator™ (R³) 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:- PWM 型:電流模式 輸出數(shù):1 頻率 - 最大:275kHz 占空比:50% 電源電壓:18 V ~ 110 V 降壓:無(wú) 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:是 工作溫度:-40°C ~ 85°C 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 包裝:帶卷 (TR) |
| ISL6269ACRZ-TR5453 | 制造商:Intersil Corporation 功能描述:STD. ISL6269ACRZ-T WITH GOLD BOND WIRE ONLY, T&R - Tape and Reel |
| ISL6269AEVAL2 | 制造商:Intersil Corporation 功能描述:ISL6269A EVALUATION BOARD 2 - Bulk |
| ISL6269AEVAL2Z | 功能描述:EVALUATION BOARD FOR ISL6269A RoHS:是 類(lèi)別:編程器，開(kāi)發(fā)系統(tǒng) >> 評(píng)估板 - DC/DC 與 AC/DC（離線）SMPS 系列:Robust Ripple Regulator™ (R³) 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:True Shutdown™ 主要目的:DC/DC，步升 輸出及類(lèi)型:1，非隔離 功率 - 輸出:- 輸出電壓:- 電流 - 輸出:1A 輸入電壓:2.5 V ~ 5.5 V 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):升壓 頻率 - 開(kāi)關(guān):3MHz 板類(lèi)型:完全填充 已供物品:板 已用 IC / 零件:MAX8969 |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。