- 您现在的位置：买卖IC网 > PDF目录17644 > ISL9443IRZ-T (Intersil)IC REG CTRLR BUCK PWM CM 32-QFN PDF资料下载
参数资料
| 型号： | ISL9443IRZ-T |
| 厂商： | Intersil |
| 文件页数： | 21/23页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM CM 32-QFN |
| 标准包装： | 6,000 |
| PWM 型： | 电流模式 |
| 输出数： | 3 |
| 频率 - 最大： | 1.32MHz |
| 电源电压： | 4.5 V ~ 26 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | * |
| 包装： | * |
ISL9443
Use only specialized low-ESR capacitors intended for
switching-regulator applications for the bulk capacitors. In most
5.0
cases, multiple small-case electrolytic capacitors perform better
than a single large-case capacitor.
The stability requirement on the selection of the output capacitor
is that the ‘ESR zero’ (f Z ) be between 2kHz and 60kHz. This range
is set by an internal, single compensation zero at 8.8kHz. The
ESR zero can be a factor of five on either side of the internal zero
and still contribute to increased phase margin of the control loop.
4.5
4.0
3.5
3.0
2.5
2.0
IN PHASE
OUT-OF-PHASE
C OUT = ----------------------------------
Therefore:
1
2 π ( ESR ) ( f Z )
(EQ. 17)
1.5
1.0
0.5
3.3V
5V
In conclusion, the output capacitors must meet three criteria:
1. They must have sufficient bulk capacitance to sustain the
0
0
1
2 3
3.3V AND 5V LOAD CURRENT
4
5
output voltage during a load transient while the output
inductor current is slewing to the value of the load transient.
2. The ESR must be sufficiently low to meet the desired output
voltage ripple due to the output inductor current.
3. The ESR zero should be placed, in a rather large range, to
provide additional phase margin.
The recommended output capacitor value for the ISL9443 is
between 100μF to 680μF, to meet stability criteria with external
compensation. Use of aluminum electrolytic (POSCAP) or
tantalum type capacitors is recommended. Use of low ESR
ceramic capacitors is possible but would take more rigorous loop
analysis to ensure stability.
Input Capacitor Selection
The important parameters for the bulk input capacitor(s) are the
voltage rating and the RMS current rating. For reliable operation,
select bulk input capacitors with voltage and current ratings
above the maximum input voltage and largest RMS current
required by the circuit. The capacitor voltage rating should be at
least 1.25 times greater than the maximum input voltage and
1.5 times is a conservative guideline. The AC RMS Input current
varies with the load. The total RMS current supplied by the input
capacitance is:
FIGURE 24. INPUT RMS CURRENT vs LOAD
Depending on the specifics of the input power and its
impedance, most (or all) of this current is supplied by the input
capacitor(s). Figure 24 shows the advantage of having the PWM
converters operating out-of-phase. If the converters were
operating in-phase, the combined RMS current would be the
algebraic sum, which is a much larger value as shown. The
combined out-of-phase current is the square root of the sum of
the square of the individual reflected currents and is significantly
less than the combined in-phase current.
Use a mix of input bypass capacitors to control the voltage ripple
across the MOSFETs. Use ceramic capacitors for the high
frequency decoupling and bulk capacitors to supply the RMS
current. Small ceramic capacitors can be placed very close to the
upper MOSFET to suppress the voltage induced in the parasitic
circuit impedances.
For board designs that allow through-hole components, the
Sanyo OS-CON? series offers low ESR and good temperature
performance. For surface mount designs, solid tantalum
capacitors can be used, but caution must be exercised with
regard to the capacitor surge current rating. These capacitors
must be capable of handling the surge-current at power-up. The
I RMS1 + I RMS2
I RMS =
2 2
(EQ. 18)
TPS series available from AVX is surge current tested.
Where DC is duty cycle of the respective PWM.
DC – DC ? I O
I RMSx =
2
21
(EQ. 19)
FN7663.1
February 24, 2012
相关PDF资料 |
PDF描述 |
|---|---|
| FOXSDLF/221-20 | CRYSTAL 22.1184 MHZ 20PF SMD |
| ZL2004ALNFT1 | IC REG CTRLR BUCK SYNC ADJ 32QFN |
| SBG3030CT-T | DIODE SCHOTTKY CC 30V 30A D2-PAK |
| FOXSDLF/115-20 | CRYSTAL 11.0592 MHZ 20PF SMD |
| ISL62392CIRTZ-T | IC PWR SUPPLY CTRLR 28TQFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL9443IRZ-T7A | 功能描述:软开关 PWM 控制器 ISL9443 TRIPLE STEP CONTRLR IMVP-6. 32LD RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel |
| ISL9443IRZ-T7AS2750 | 制造商:Intersil Corporation 功能描述:ISL9443 TRIPLE, STEP- DOWN PWM CONTROLLER IMVP-6. 32 LD MLFP - Tape and Reel |
| ISL9443IRZ-TS2750 | 制造商:Intersil Corporation 功能描述:PB FREE. ISL9443 TRIPLE, STEP- DOWN PWM CONTROLLER IMVP-6. 3 - Tape and Reel |
| ISL9444CRZ | 制造商:Intersil Corporation 功能描述:PB FREE. ISL9444 TRIPLE, STEP- DOWN PWM CONTROLLER IMVP-6. 4 - Rail/Tube 制造商:Intersil Corporation 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN 制造商:Intersil 功能描述:Pb Free. ISL9444 Tri ple, Step- Down PWM |
| ISL9444CRZ-T | 制造商:Intersil Corporation 功能描述:PB FREE. ISL9444 TRIPLE, STEP- DOWN PWM CONTROLLER IMVP-6. 4 - Tape and Reel 制造商:Intersil Corporation 功能描述:IC REG CTRLR BUCK PWM CM 32-QFN 制造商:Intersil 功能描述:Pb Free. ISL9444 Tri ple, Step- Down PWM |
发布紧急采购，3分钟左右您将得到回复。