参数资料
型号: IR3502AMTRPBF
厂商: International Rectifier
文件页数: 12/38页
文件大小: 0K
描述: IC XPHASE CTRL VR11.0/1 32-MLPQ
标准包装: 1
系列: XPhase3™
应用: 处理器
电流 - 电源: 8mA
电源电压: 8 V ~ 16 V
工作温度: 0°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-MLPQ(5x5)
包装: 标准包装
其它名称: IR3502AMTRPBFDKR
IR3502A
resistor with the value of R L was used. The mismatch of the time constants does not affect the measurement of
inductor DC current, but affects the AC component of the inductor current.
v L
i L
Current
Sense Amp
L
R C
R L
C C
v C c
V O
C O
CSOUT
Figure 6 Inductor Current Sensing and Current Sense Amplifier
The advantage of sensing the inductor current versus high side or low side sensing is that actual output current being
delivered to the load is obtained rather than peak or sampled information about the switch currents. The output voltage
can be positioned to meet a load line based on real time information. Except for a sense resistor in series with the
inductor, this is the only sense method that can support a single cycle transient response. Other methods provide no
information during either load increase (low side sensing) or load decrease (high side sensing).
An additional problem associated with peak or valley current mode control for voltage positioning is that they suffer
from peak-to-average errors. These errors will show in many ways but one example is the effect of frequency variation.
If the frequency of a particular unit is 10% low, the peak to peak inductor current will be 10% larger and the output
impedance of the converter will drop by about 10%. Variations in inductance, current sense amplifier bandwidth, PWM
prop delay, any added slope compensation, input voltage, and output voltage are all additional sources of peak-to-
average errors.
Current Sense Amplifier
A high speed differential current sense amplifier is located in the phase IC, as shown in Figure 6. Its gain is nominally
33 at 25oC, and the 3850 ppm/oC increase in inductor DCR should be compensated in the voltage loop feedback path.
The current sense amplifier can accept positive differential input up to 50mV and negative up to -10mV before clipping.
The output of the current sense amplifier is summed with the VDAC voltage and sent to the control IC and other
phases through an on-chip 3K ? resistor connected to the IIN pin. The IIN pins of all the phases are tied together and
the voltage on the share bus represents the average current through all the inductors and is used by the control IC for
voltage positioning and current limit protection. The input offset of this amplifier is calibrated to +/- 1mV in order to
reduce the current sense error.
The input offset voltage is the primary source of error for the current share loop. In order to achieve very small input
offset error and superior current sharing performance, the current sense amplifier continuously calibrates itself. This
calibration algorithm creates ripple on IIN bus with a frequency of fsw/(32*28) in a multiphase architecture.
Average Current Share Loop
Current sharing between the phases of the converter is achieved by the average current share loop in each phase IC.
The output of the current sense amplifier is compared with average current at the share bus. If current in a phase is
smaller than the average current, the share adjust amplifier of the phase will pull down the starting point of the PWM
ramp thereby increasing its duty cycle and output current; if current in a phase is larger than the average current, the
share adjust amplifier of the phase will pull up the starting point of the PWM ramp thereby decreasing its duty cycle and
output current. The current share amplifier is internally compensated; such that, the crossover frequency of the current
share loop is much slower than that of the voltage loop and the two loops do not interact.
Page 12 of 38
December 17, 2009
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相关代理商/技术参数
参数描述
IR3502B 制造商:IRF 制造商全称:International Rectifier 功能描述:XPHASE3TM CONTROL IC
IR3502BMTRPBF 功能描述:开关变换器、稳压器与控制器 X-PHASE CONTROL IC AMD SVID CTRL IC RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel
IR3502MPBF 制造商:International Rectifier 功能描述:IR3502 Series 16 V 1.65 MHz Surface Mount XPHASE3TM Control IC- MLPQ-32 制造商:IR 功能描述:IR3502 Series 16 V 1.65 MHz Surface Mount XPHASE3TM Control IC- MLPQ-32
IR3502MPBFTR 制造商:IRF 制造商全称:International Rectifier 功能描述:XPHASE3TM CONTROL IC
IR3502MTRPBF 功能描述:开关变换器、稳压器与控制器 COMPLETE VR11.0 OR VR11.1 PWR SOLUTION RoHS:否 制造商:Texas Instruments 输出电压:1.2 V to 10 V 输出电流:300 mA 输出功率: 输入电压:3 V to 17 V 开关频率:1 MHz 工作温度范围: 安装风格:SMD/SMT 封装 / 箱体:WSON-8 封装:Reel