参数资料
| 型号： | ISL62882IRTZ |
| 厂商： | Intersil |
| 文件页数： | 21/42页 |
| 文件大小： | 0K |
| 描述： | IC REG PWM 2PHASE BUCK 40TQFN |
| 标准包装： | 60 |
| 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： | -40°C ~ 100°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 40-WFQFN 裸露焊盘 |
| 供应商设备封装： | 40-TQFN-EP（5x5） |
| 包装： | 管件 |
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ISL62882, ISL62882B
R ntcs + R ntc + R p
1 + ------
A cs ( s ) = ----------------------
1 + ------------
ω L = ------------
Rsum
ω sns = ------------------------------------------------------
R ntcnet × --------------
----------------------------------------- × C n
Care should be taken in layout that the resistor is placed very
close to the RBIAS pin and that a good quality signal ground is
connected to the opposite side of the R BIAS resistor.
R is and C is
As Figures 1 thru 4 show, the ISL62882 needs the R is - C is
network across the ISUM+ and the ISUM- pins to stabilize the
droop amplifier. The preferred values are R is = 82.5 Ω and
C is = 0.01μF. Slight deviations from the recommended values
are acceptable. Large deviations may result in instability.
Inductor DCR Current-Sensing Network
Phase1 Phase2
Rsum
ISUM+
( R ntcs + R ntc ) × R p
R ntcnet = ---------------------------------------------------
s
ω L
s
ω sns
DCR
L
1
R sum
N
N
R sum
R ntcnet + --------------
where N is the number of phases.
(EQ. 15)
(EQ. 16)
(EQ. 17)
(EQ. 18)
L
L
Rntcs
Rp
Cn Vcn
Transfer function A cs (s) always has unity gain at DC. The inductor
DCR value increases as the winding temperature increases,
giving higher reading of the inductor DC current. The NTC R ntc
values decreases as its temperature decreases. Proper
DCR
DCR
Rntc
Ro
Ri
ISUM-
selections of R sum , R ntcs , R p and R ntc parameters ensure that
V Cn represent the inductor total DC current over the temperature
range of interest.
C n = ------------------------------------------------------------
L
R sum
Ro
Io
FIGURE 17. DCR CURRENT-SENSING NETWORK
Figure 17 shows the inductor DCR current-sensing network for a
2-phase solution. An inductor current flows through the DCR and
creates a voltage drop. Each inductor has two resistors in R sum and
R o connected to the pads to accurately sense the inductor current by
sensing the DCR voltage drop. The R sum and R o resistors are
connected in a summing network as shown, and feed the total
current information to the NTC network (consisting of R ntcs , R ntc
and R p ) and capacitor C n . R ntc is a negative temperature coefficient
(NTC) thermistor, used to temperature-compensate the inductor
DCR change.
The inductor output side pads are electrically shorted in the
schematic, but have some parasitic impedance in actual board
layout, which is why one cannot simply short them together for the
current-sensing summing network. It is recommended to use
1 Ω ~10 Ω R o to create quality signals. Since R o value is much
smaller than the rest of the current sensing circuit, the following
analysis will ignore it for simplicity.
The summed inductor current information is presented to the
capacitor C n . Equations 14 thru 18 describe the
frequency-domain relationship between inductor total current
I o (s) and C n voltage V Cn (s).
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.
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 19 gives C n value.
(EQ. 19)
N
R ntcnet × --------------
----------------------------------------- × DCR
N
R sum
R ntcnet + --------------
V Cn ( s ) = ? ----------------------------------------- × ------------ ? × I o ( s ) × A cs ( s )
? ?
N
? R ntcnet DCR ?
? R sum N ?
? R ntcnet + -------------- ?
21
(EQ. 14)
FN6890.4
June 21, 2011
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| ISL62882IRTZ-T | 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 |
| ISL62883 | 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 |
| ISL62883BHRTZ | 功能描述:直流/直流开关调节器 3 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 |
| ISL62883BHRTZ-T | 功能描述:直流/直流开关调节器 3 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 |
| ISL62883C | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Multiphase PWM Regulator for IMVP-6.5a?￠ Mobile CPUs and GPUs |
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