參數(shù)資料
型號(hào)： ISL6308CRZ
廠商： INTERSIL CORP
元件分類： 穩(wěn)壓器
英文描述： Three-Phase Buck PWM Controller with High Current Integrated MOSFET Drivers
中文描述： SWITCHING CONTROLLER, 1500 kHz SWITCHING FREQ-MAX, PQCC40
封裝： 6 X 6 MM, ROHS COMPLIANT, PLASTIC, MO-220VJJD-1, QFN-40
文件頁(yè)數(shù)： 15/27頁(yè)
文件大?。?/td> 765K
代理商： ISL6308CRZ
15
FN9208.2
October 19, 2005
Initialization
Prior to initialization, proper conditions must exist on the
ENLL, VCC, PVCC and the REF0 and REF1 pins. When the
conditions are met, the controller begins soft-start. Once the
output voltage is within the proper window of operation, the
controller asserts PGOOD.
Enable and Disable
While in shutdown mode, the PWM outputs are held in a
high-impedance state to assure the drivers remain off. The
following input conditions must be met before the ISL6308 is
released from shutdown mode.
1. The bias voltage applied at VCC must reach the internal
power-on reset (POR) rising threshold. Once this
threshold is reached, proper operation of all aspects of
the ISL6308 is guaranteed. Hysteresis between the rising
and falling thresholds assure that once enabled, the
ISL6308 will not inadvertently turn off unless the bias
voltage drops substantially (see
Electrical
Specifications
).
2. The voltage on ENLL must be above 0.66V. The EN input
allows for power sequencing between the controller bias
voltage and another voltage rail. The enable comparator
holds the ISL6308 in shutdown until the voltage at ENLL
rises above 0.66V. The enable comparator has 100mV of
hysteresis to prevent bounce.
3. The driver bias voltage applied at the PVCC pins must
reach the internal power-on reset (POR) rising threshold.
In order for the ISL6308 to begin operation, PVCC1 is the
only pin that is required to have a voltage applied that
exceeds POR. However, for 2 or 3-phase operation
PVCC2 and PVCC3 must also exceed the POR
threshold. Hysteresis between the rising and falling
thresholds assure that once enabled, the ISL6308 will not
inadvertently turn off unless the PVCC bias voltage drops
substantially (see
Electrical Specifications
).
When each of these conditions is true, the controller
immediately begins the soft-start sequence.
Soft-Start
During soft-start, the DAC voltage ramps linearly from zero
to the programmed level. The PWM signals remain in the
high-impedance state until the controller detects that the
ramping DAC level has reached the output-voltage level.
This protects the system against the large, negative inductor
currents that would otherwise occur when starting with a pre-
existing charge on the output as the controller attempted to
regulate to zero volts at the beginning of the soft-start cycle.
The Output soft-start time, T
SS
, begins with a delay period
equal to 64 switching cycles after the ENLL has exceeded its
POR level, followed by a linear ramp with a rate determined
by the switching period, 1/F
sw
.
For example, a regulator with 450kHz switching frequency
having REF voltage set to 1.2V has T
SS
equal to 3.55ms.
A 100mV offset exists on the remote-sense amplifier at the
beginning of soft-start and ramps to zero during the first 640
cycles of soft-start (704 cycles following enable). This
prevents the large inrush current that would otherwise occur
should the output voltage start out with a slight negative
bias.
The ISL6308 also has the ability to start up into a pre-
charged output as shown in Figure 12, without causing any
unnecessary disturbance. The FB pin is monitored during
soft-start, and should it be higher than the equivalent internal
ramping reference voltage, the output drives hold both
MOSFETs off. Once the internal ramping reference exceeds
the FB pin potential, the output drives are enabled, allowing
the output to ramp from the pre-charged level to the final
level dictated by the reference setting. Should the output be
pre-charged to a level exceeding the reference setting, the
output drives are enabled at the end of the soft-start period,
leading to an abrupt correction in the output voltage down to
the “reference set” level.
FIGURE 11. POWER SEQUENCING USING THRESHOLD-
SENSITIVE ENABLE (ENLL) FUNCTION
-
+
0.66V
EXTERNAL CIRCUIT
ISL6308 INTERNAL CIRCUIT
ENLL
+12V
POR
CIRCUIT
10.7k
1.40k
ENABLE
COMPARATOR
SOFT-START
AND
FAULT LOGIC
VCC
PVCC1
T
SS
--------+
F
SW
1280
=
(EQ. 12)
ISL6308
相關(guān)PDF資料
PDF描述
ISL6308CRZ-T Quadruple 2-Input Exclusive-OR Gates 14-SOIC -40 to 85
ISL6308IRZ-T Three-Phase Buck PWM Controller with High Current Integrated MOSFET Drivers
ISL6315 Two-Phase Multiphase Buck PWM Controller with Integrated MOSFET Drivers(帶集成MOSFET驅(qū)動(dòng)器的雙相降壓PWM控制器)
ISL6316 Quadruple 2-Input Exclusive-OR Gates 14-SOIC -40 to 85
ISL6316IRZ MINIATURE TOGGLE SWITCH
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ISL6308CRZR5374 制造商:Intersil Corporation 功能描述:ISL6308CRZ W/ 24HR BURN-IN - Rail/Tube 制造商:Intersil Corporation 功能描述:IC CTRLR PWM 3PHASE BUCK 40-QFN 制造商:Intersil 功能描述:ISL6308CRZ W/24HRU RN-IN
ISL6308CRZ-T 功能描述:電壓模式 PWM 控制器 DAC-LESS MULTI-PHS PWM CNTRLR W/3-DRVRS RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓?fù)浣Y(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關(guān)頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
ISL6308CRZ-TR5374 制造商:Intersil Corporation 功能描述:ISL6308CRZ W/ 24HR BURN-IN - Tape and Reel 制造商:Intersil Corporation 功能描述:IC CTRLR PWM 3PHASE BUCK 40-QFN 制造商:Intersil 功能描述:ISL6308CRZ W/24HRU RN-IN
ISL6308CRZ-TR5453 制造商:Intersil Corporation 功能描述:STD. ISL6308CRZ-T W/GOLD BOND WIRE ONLY - Tape and Reel
ISL6308EVAL1Z 制造商:Intersil Corporation 功能描述:ISL6308 EVALUATION BOARD 1 - ROHS COMPLIANT - QFN - Bulk
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

*
*
*