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参数资料
| 型号： | ISL6307BCRZ |
| 厂商： | Intersil |
| 文件页数： | 27/33页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR BUCK PWM VM 48-QFN |
| 标准包装： | 43 |
| PWM 型： | 电压模式 |
| 输出数： | 6 |
| 频率 - 最大： | 275kHz |
| 占空比： | 66.7% |
| 电源电压： | 4.75 V ~ 5.25 V |
| 降压： | 是 |
| 升压： | 无 |
| 回扫： | 无 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | 0°C ~ 70°C |
| 封装/外壳： | 48-VFQFN 裸露焊盘 |
| 包装： | 管件 |
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ISL6307B
P UP , 1 ≈ V IN ? ------ + ----------- ? ? ---- 1 ? f S
be used, higher per-phase currents are possible. In cases
where board space is the limiting constraint, current can be
pushed as high as 40A per phase, but these designs require
heat sinks and forced air to cool the MOSFETs, inductors
and heat-dissipating surfaces.
the required time for this commutation is t 1 and the
approximated associated power loss is P UP,1 .
I M I P-P ? t ?
? N 2 ? ? 2 ?
(EQ. 26)
MOSFETS
The choice of MOSFETs depends on the current each
MOSFET will be required to conduct; the switching
At turn on, the upper MOSFET begins to conduct and this
transition occurs over a time t 2 . In Equation 27, the
approximate power loss is P UP,2 .
P UP , 2 ≈ V IN ? ------ – ----------- ? ? ---- 2 ? f S
frequency; the capability of the MOSFETs to dissipate heat;
and the availability and nature of heat sinking and air flow.
LOWER MOSFET POWER CALCULATION
? N 2 ? ? 2 ?
I M I P-P ? t ?
(EQ. 27)
P UP , 3 = V IN Q rr f S
The calculation for heat dissipated in the lower MOSFET is
simple, since virtually all of the heat loss in the lower
MOSFET is due to current conducted through the channel
resistance (R DS(ON) ). In Equation 24, I M is the maximum
continuous output current; I P-P is the peak-to-peak inductor
current (see Equation 1); d is the duty cycle (V OUT /V IN ); and
L is the per-channel inductance.
A third component involves the lower MOSFET’s reverse-
recovery charge, Q rr . Since the inductor current has fully
commutated to the upper MOSFET before the lower-
MOSFET’s body diode can draw all of Q rr , it is conducted
through the upper MOSFET across VIN. The power
dissipated as a result is P UP,3 and is approximately
(EQ. 28)
? I M ? 2 I L , P-P ( 1 – d )
? ------ ? ( 1 – d ) + -----------------------------------
P LOW , 1 = R DS ( ON )
? N ? 12
(EQ. 24)
Finally, the resistive part of the upper MOSFET’s is given in
Equation 29 as P UP,4 .
An additional term can be added to the lower-MOSFET loss
equation to account for additional loss accrued during the
dead time when inductor current is flowing through the
lower-MOSFET body diode. This term is dependent on the
diode forward voltage at I M , V D(ON) ; the switching
frequency, f S ; and the length of dead times, t d1 and t d2 , at
the beginning and the end of the lower-MOSFET conduction
The total power dissipated by the upper MOSFET at full load
can now be approximated as the summation of the results
from Equations 26, 27, 28 and 29. Since the power
equations depend on MOSFET parameters, choosing the
correct MOSFETs can be an iterative process involving
repetitive solutions to the loss equations for different
MOSFETs and different switching frequencies.
P LOW , 2 = V D ( ON ) f S ? ------ + I ----------- ? t
I P-P ?
? I
d1 + ? ------ – ----------- ? t d2
? I M ?
I P-P
P UP , 4 ≈ R DS ( ON ) ? ------ ? d + ----------- d
interval respectively.
I M P-P
? N 2 ?
M
? N 2 ?
(EQ. 25)
2 2
? N ? 12
(EQ. 29)
R ISEN = -----------------------
50 × 10 – 6
Thus the total maximum power dissipated in each lower
MOSFET is approximated by the summation of P LOW,1 and
P LOW,2 .
UPPER MOSFET POWER CALCULATION
In addition to R DS(ON) losses, a large portion of the upper-
MOSFET losses are due to currents conducted across the
input voltage (V IN ) during switching. Since a substantially
higher portion of the upper-MOSFET losses are dependent
on switching frequency, the power calculation is more
complex. Upper MOSFET losses can be divided into
separate components involving the upper-MOSFET
switching times; the lower-MOSFET body-diode reverse-
recovery charge, Q rr ; and the upper MOSFET R DS(ON)
conduction loss.
When the upper MOSFET turns off, the lower MOSFET does
not conduct any portion of the inductor current until the
voltage at the phase node falls below ground. Once the
lower MOSFET begins conducting, the current in the upper
MOSFET falls to zero as the current in the lower MOSFET
ramps up to assume the full inductor current. In Equation 26,
27
Current Sensing Resistor
The resistors connected between these ISEN+ pins and the
respective phase nodes or output side of the output inductor
determine the gains in the load-line regulation loop and the
channel-current balance loop as well as setting the
overcurrent trip point. Select values for these resistors based
on the room temperature R DS(ON) of the lower MOSFETs,
DCR of inductor or additional resistor; the full-load operating
current, I FL ; and the number of phases, N using Equation 30.
R X I FL (EQ. 30)
--------
N
In certain circumstances, it may be necessary to adjust the
value of one or more ISEN resistors. When the components
of one or more channels are inhibited from effectively
dissipating their heat so that the affected channels run hotter
than desired, choose new, smaller values of RISEN for the
affected phases (see the section entitled Channel-Current
Balance ). Choose R ISEN,2 in proportion to the desired
FN9225.0
March 9, 2006
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| ISL6307BCRZ-T | 功能描述:软开关 PWM 控制器 W/ANNEAL 6-PHS VR11 CNTRLR COM TAPE AND RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel |
| ISL6307BIRZ | 功能描述:软开关 PWM 控制器 W/ANNEAL 6-PHS VR11 CNTRLR INDUSTRIAL RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel |
| ISL6307BIRZ-T | 功能描述:软开关 PWM 控制器 W/ANNEAL 6-PHS VR11 CNTRLR INDUSTRIAL RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel |
| ISL6307CRZ | 功能描述:IC REG CTRLR BUCK PWM VM 48-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
| ISL6307CRZ-T | 功能描述:IC REG CTRLR BUCK PWM VM 48-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:275kHz 占空比:50% 电源电压:18 V ~ 110 V 降压:无 升压:无 回扫:无 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:-40°C ~ 85°C 封装/外壳:8-SOIC（0.154"，3.90mm 宽） 包装:带卷 (TR) |
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