参数资料
| 型号： | ISL6263BHRZ-T |
| 厂商： | Intersil |
| 文件页数： | 16/18页 |
| 文件大小： | 0K |
| 描述： | IC DC/DC BUCK CTRLR 1PH 32-QFN |
| 标准包装： | 6,000 |
| 应用： | 转换器，Intel IMVP-6 |
| 输入电压： | 5 V ~ 25 V |
| 输出数： | 1 |
| 输出电压： | 0.41 V ~ 1.29 V |
| 工作温度： | -10°C ~ 100°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 32-VFQFN 裸露焊盘 |
| 供应商设备封装： | 32-QFN（5x5） |
| 包装： | 带卷 (TR) |
ISL6263B
R droop = R SNS ? ? 1 + ------------------- ?
The current sensing network consists of R NTCEQ , R S , and
C N . The effective resistance is the parallel of R NTCEQ and
R S . The RC time constant of the current sensing network
needs to match the L/DCR time constant of the inductor to
get the correct representation of the inductor current
waveform. Equation 18 shows this relationship:
Equation 22 shows the droop amplifier gain. So the actual
droop is given by:
? R DRP2 ?
? R DRP1 ? (EQ. 22)
Solution to R DRP2 yields Equation 23 :
------------- = ? --------------------------------------- ? ? C N
? R NTCEQ + R S ?
R DRP2 = R DRP1 ? ? ------------------- – 1 ?
DCR
L ? R NTCEQ ? R S ?
(EQ. 18)
? R droop ?
? R SNS ?
(EQ. 23)
? ------------- ?
? R NTCEQ ? R S ?
? R NTCEQ + R S ?
Solution of C N yields:
L
? DCR ?
C N = --------------------------------------------
? --------------------------------------- ?
(EQ. 19)
For example: R droop = 8.0m Ω , R SNS = 1.0m Ω , and
R DRP1 = 1k Ω , R DRP2 then = 7k Ω.
The current sensing traces should be routed directly to the
current sensing resistor pads for accurate measurement.
However, due to layout imperfection, the calculated R DRP2
may still need slight adjustment to achieve optimum load line
For example: L = 0.45μH, DCR = 1.1m Ω , R S = 7.68k Ω , and
R NTCEQ = 3.4k Ω:
slope. It is recommended to adjust R DRP2 after the system
has achieved thermal equilibrium at full load.
? ------------------- ?
C N = ------------------------------------------------- = 174nF
? ------------------------------------------- ?
? 1.1m Ω ?
3.4k Ω ? 7.68k Ω
? 3.4k Ω + 7.68k Ω ?
(EQ. 20)
Dynamic Mode of Operation - Compensation
Parameters
The voltage regulator is equivalent to a voltage source in
series with the output impedance. The voltage source is the
Since the inductance and the DCR typically have 20% and
7% tolerance respectively, C N needs to be fine tuned on the
actual board by examining the transient voltage. It is
recommended to choose the minimum capacitance based
on the maximum inductance. C N also needs to be a
high-grade capacitor such as NPO/COG or X7R with tight
tolerance. The NPO/COG caps are only available in small
capacitance values. In order to use such capacitors, the
resistors and thermistors surrounding the droop voltage
sensing and droop amplifier need to be scaled up 10x to
reduce the capacitance by 10x.
Static and Dynamic Droop using Discrete Resistor
Sensing
Figure 3 shows a detailed schematic using discrete resistor
sensing of the inductor current. Figure 9 shows the
equivalent circuit. Since the current sensing resistor voltage
represents the actual inductor current information, R S and
C N simply provide noise filtering. A low ESL sensing resistor
is strongly recommended for R SNS because this parameter
is the most significant source of noise that affects discrete
resistor sensing. It is recommended to start out using 100 Ω
for R S and 47pF for C N . Since the current sensing
resistance changes very little with temperature, the NTC
network is not needed for thermal compensation. Discrete
resistor sensing droop design follows the same approach as
DCR sensing. The voltage on the current sensing resistor is
given by Equation 21:
VID state and the output impedance is 8.0m Ω in order to
achieve the 8.0mV/A load line. It is highly recommended to
design the compensation such that the regulator output
impedance is 8.0m Ω . Intersil provides a spreadsheet to
calculate the compensator parameters. Caution needs to be
used in choosing the input resistor to the FB pin. Excessively
high resistance will cause an error to the output voltage
regulation due to the bias current flowing through the FB pin.
It is recommended to keep this resistor below 3k Ω .
Layout Considerations
As a general rule, power should be on the bottom layer of
the PCB and weak analog or logic signals are on the top
layer of the PCB. The ground-plane layer should be adjacent
to the top layer to provide shielding.
Inductor Current Sensing and the NTC Placement
It is crucial that the inductor current be sensed directly at the
PCB pads of the sense element, be it DCR sensed or discrete
resistor sensed. The effect of the NTC on the inductor DCR
thermal drift is directly proportional to its thermal coupling with
the inductor and thus, the physical proximity to it.
Signal Ground and Power Ground
The ground plane layer should have a single point connection
to the analog ground at the VSS pin. The VSS island should
be located under the IC package along with the weak analog
traces and components. The paddle on the bottom of the
V RSNS = I o ? R SNS
16
(EQ. 21)
ISL6263B QFN package is not electrically connected to the IC
however, it is recommended to make a good thermal
connection to the VSS island using several vias. Connect the
input capacitors, the output capacitors, and the source of the
lower MOSFETs to the power ground plane.
FN6388.3
July 8, 2010
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相关代理商/技术参数 |
参数描述 |
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| ISL6263C | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:5-Bit VID Single-Phase Voltage Regulator with Current Monitor for GPU Core Power |
| ISL6263CEVAL1 | 功能描述:EVAL BOARD 1 FOR ISL6263C RoHS:否 类别:编程器，开发系统 >> 评估板 - 线性稳压器 (LDO) 系列:* 产品变化通告:1Q2012 Discontinuation 30/Mar/2012 设计资源:NCP590MNDPTAGEVB Gerber Files 标准包装:1 系列:- 每 IC 通道数:2 - 双 输出电压:1.8V，2.8V 电流 - 输出:300mA 输入电压:2.1 ~ 5.5 V 稳压器类型:正，固定式 工作温度:-40°C ~ 85°C 板类型:完全填充 已供物品:板 已用 IC / 零件:NCP590MNDP 其它名称:NCP590MNDPTAGEVB-NDNCP590MNDPTAGEVBOS |
| ISL6263CHRZ | 功能描述:直流/直流开关调节器 1-PHS INT DC/DC BUCK CNTRLR IMVP-6 W/IMON RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| ISL6263CHRZ-T | 功能描述:直流/直流开关调节器 1-PHS INT DC/DC BUCK CNTRLR IMVP-6 W/IMON RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| ISL6263CRZ | 功能描述:直流/直流开关调节器 1 PHS INT DC/DC BUCK CNTRLR FOR INTEL RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
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