参数资料
| 型号： | ISL62881HRTZ |
| 厂商： | Intersil |
| 文件页数： | 19/35页 |
| 文件大小： | 0K |
| 描述： | IC REG PWM SGL PHASE 28TQFN |
| 标准包装： | 75 |
| 应用： | 控制器，Intel IMVP-6.5? |
| 输入电压： | 5 V ~ 25 V |
| 输出数： | 1 |
| 输出电压： | 0.013 V ~ 1.5 V |
| 工作温度： | -10°C ~ 100°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 供应商设备封装： | 28-TQFN-EP（4x4） |
| 包装： | 管件 |
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ISL62881, ISL62881B
There are many sets of parameters that can properly
temperature-compensate the DCR change. Since the NTC
network and the R sum resistors form a voltage divider, V cn is
always a fraction of the inductor DCR voltage. It is recommended
to have a higher ratio of V cn to the inductor DCR voltage, so the
droop circuit has higher signal level to work with.
A typical set of parameters that provide good temperature
compensation are: R sum = 3.65k Ω , R p = 11k Ω , R ntcs = 2.61k Ω
and R ntc = 10k Ω (ERT-J1VR103J). The NTC network parameters
may need to be fine tuned on actual boards. One can apply full
load DC current and record the output voltage reading
immediately; then record the output voltage reading again when
the board has reached the thermal steady state. A good NTC
network can limit the output voltage drift to within 2mV. It is
recommended to follow the Intersil evaluation board layout and
current-sensing network parameters to minimize engineering
time.
For example, given R sum = 3.65k Ω , R p = 11k Ω , R ntcs = 2.61k Ω ,
R ntc = 10k Ω , DCR = 1.1m Ω and L = 0.45μH, Equation 12 gives
C n = 0.18μF.
Assuming the compensator design is correct, Figure 14 shows
the expected load transient response waveforms if C n is correctly
selected. When the load current I core has a square change, the
output voltage V core also has a square response.
If C n value is too large or too small, V Cn (s) will not accurately
represent real-time I o (s) and will worsen the transient response.
Figure 15 shows the load transient response when C n is too
small. V core will sag excessively upon load insertion and may
create a system failure. Figure 16 shows the transient response
when C n is too large. V core is sluggish in drooping to its final
value. There will be excessive overshoot if load insertion occurs
during this time, which may potentially hurt the CPU reliability.
L
C n = ------------------------------------------------------------
R ntcnet × R sum
V Cn (s) also needs to represent real-time I o (s) for the controller to
achieve good transient response. Transfer function A cs (s) has a
pole ω sns and a zero ω L . One needs to match ω L and ω sns so
A cs (s) is unity gain at all frequencies. By forcing ω L equal to ω sns
and solving for the solution, Equation 12 gives C n value.
(EQ. 12)
----------------------------------------- × DCR
R ntcnet + R sum
i O
RING
BACK
i L
V O
FIGURE 17. OUTPUT VOLTAGE RING BACK PROBLEM
i o
ISUM+
V o
FIGURE 14. DESIRED LOAD TRANSIENT RESPONSE WAVEFORMS
Rntcs
Rntc
Rp
Cn.1
Rn
OPTIONAL
+
Cn.2 Vcn
-
ISUM-
Ri
i o
Rip
Cip
V o
FIGURE 15. LOAD TRANSIENT RESPONSE WHEN C n IS TOO SMALL
i o
V o
FIGURE 16. LOAD TRANSIENT RESPONSE WHEN C n IS TOO LARGE
19
OPTIONAL
FIGURE 18. OPTIONAL CIRCUITS FOR RING BACK REDUCTION
Figure 17 shows the output voltage ring back problem during
load transient response. The load current i o has a fast step
change, but the inductor current i L cannot accurately follow.
Instead, i L responds in first order system fashion due to the
nature of current loop. The ESR and ESL effect of the output
capacitors makes the output voltage V o dip quickly upon load
current change. However, the controller regulates V o according to
the droop current i droop , which is a real-time representation of i L ;
therefore it pulls V o back to the level dictated by i L , causing the
ring back problem. This phenomenon is not observed when the
output capacitors have very low ESR and ESL, such as all ceramic
capacitors.
FN6924.3
June 16, 2011
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相关代理商/技术参数 |
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|---|---|
| ISL62881HRTZ-T | 功能描述:直流/直流开关调节器 1 PHS PWM BUCKG FOR MICROPROCESR PWR SUP 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 |
| ISL62882 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Multiphase PWM Regulator for IMVP-6.5 Mobile CPUs and GPUs |
| ISL62882B | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Multiphase PWM Regulator for IMVP-6.5 Mobile CPUs and GPUs |
| ISL62882BHRTZ | 功能描述:直流/直流开关调节器 2 PHS PWM BUCKG FOR MICROPROC PWR SUP 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 |
| ISL62882BHRTZR5411 | 制造商:Intersil Corporation 功能描述: |
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