参数资料
| 型号： | ISL78211ARZ |
| 厂商： | Intersil |
| 文件页数： | 22/35页 |
| 文件大小： | 0K |
| 描述： | IC REG 1PHASE BUCK 40QFN |
| 标准包装： | 50 |
| 应用： | 转换器，Intel IMVP-6 |
| 输入电压： | 5 V ~ 21 V |
| 输出数： | 1 |
| 输出电压： | 0.3 V ~ 1.5 V |
| 工作温度： | -40°C ~ 105°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 40-VFQFN 裸露焊盘 |
| 供应商设备封装： | 40-QFN（6x6） |
| 包装： | 管件 |
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ISL78211
V rsen = R sen ? I o
R droop = R sen ? ? 1 +
?
?
R drp 1 ? ?
board. Compared with potential long-term damage on CPU
reliability, an immediate system failure is worse. Thus, it is
desirable to avoid the waveforms shown in Figure 11. It is
recommended to choose the minimum C n value based on the
maximum inductance so only the scenarios of Figures 10 and 12
may happen. It should be noted that, after calculation, fine-
tuning of C n value may still be needed to account for board
parasitics. C n also needs to be a high-grade cap like X7R with low
tolerance. Another good option is the NPO/COG (Class-I)
capacitor, featuring only 5% tolerance and very good thermal
characteristics. But 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. Attention needs to be paid in balancing the
impedance of droop amplifier.
Dynamic Mode of Operation - Compensation
Parameters
The voltage regulator is equivalent to a voltage source equal to
VID in series with the output impedance. The output impedance
needs to be 2.1m Ω in order to achieve the 2.1mV/A load line. It
is highly recommended to design the compensation such that
the regulator output impedance is 2.1m Ω . A type-III compensator
is recommended to achieve the best performance. Intersil
provides a spreadsheet to design the compensator parameters.
Droop using Discrete Resistor Sensing -
Static/Dynamic Mode of Operation
Figure 3 shows a detailed schematic using discrete resistor
sensing of the inductor current. Figure 14 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. The most significant noise comes from the ESL of
the current sensing resistor. A low ESL sensing resistor is strongly
recommended. The recommended R s is 100 Ω and the
recommended C n is 220pF. Since the current sensing resistance
does not appreciably change with temperature, the NTC network
is not needed for thermal compensation.
Droop is designed the same way as the DCR sensing approach.
The voltage on the current sensing resistor is given by the
following Equation 31:
(EQ. 31)
Equation 24 shows the droop amplifier gain. So the actual droop
is given by Equation 32:
? R drp 2 ?
(EQ. 32)
?
Solving for R drp2 yields:
R drp 2 = R drp 1 ? ? ?
? 1 ? ?
Figure 13 shows an example of the spreadsheet. After the user
inputs the parameters in the blue font, the spreadsheet will
calculate the recommended compensator parameters (in the
pink font), and show the loop gain curves and the regulator
? R droop
? R sen
?
?
(EQ. 33)
output impedance curve. The loop gain curves need to be stable
for regulator stability, and the impedance curve needs to be
equal to or smaller than 2.1m Ω in the entire frequency range to
achieve good transient response.
The user can choose the actual resistor and capacitor values
based on the recommendation and input them in the
spreadsheet, then see the actual loop gain curves and the
regulator output impedance curve.
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 in the FB pin. It
is recommended to keep this resistor below 3k.
22
For example: R droop = 2.1m Ω . If R sen = 1m and R drp1 = 1k, easy
calculation gives that R drp2 is 1.1k.
The current sensing traces should be routed directly to the
current sensing resistor pads for accurate measurement.
However, due to layout imperfections, the calculated R drp2 may
still need slight adjustment to achieve optimum load line slope. It
is recommended to adjust R drp2 after the system has achieved
thermal equilibrium at full load.
FN7578.1
December 4, 2013
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| ISL78211ARZ-T | 功能描述:直流/直流开关调节器 AUTO GRD ONE-PHS INT W/PWR MONITOR 40L 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 |
| ISL78211ARZ-TR5303 | 制造商:Intersil Corporation 功能描述:ITSISL78211ARZ-TR5303 ONE-PHASE INT DC/D |
| ISL78213 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:3A Low Quiescent Current, High Efficiency Synchronous Buck Regulator |
| ISL78213ARZ | 功能描述:IC REG BUCK SYNC ADJ 3A 16VQFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:两者兼有 输出数:1 输出电压:5V，1 V ~ 10 V 输入电压:3.5 V ~ 28 V PWM 型:电流模式 频率 - 开关:220kHz ~ 1MHz 电流 - 输出:600mA 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:16-SSOP（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:16-QSOP |
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