参数资料
| 型号： | ISL6561CR-T |
| 厂商： | Intersil |
| 文件页数： | 13/26页 |
| 文件大小： | 0K |
| 描述： | IC CTRLR PWM MULTIPHASE 40-QFN |
| 标准包装： | 4,000 |
| 应用： | 控制器，Intel VR10X |
| 输入电压： | 3 V ~ 12 V |
| 输出数： | 4 |
| 输出电压： | 0.84 V ~ 1.6 V |
| 工作温度： | 0°C ~ 70°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： | 带卷 (TR) |
ISL6561
INDUCTOR DCR Sensing
An inductor has a distributed direct current winding
resistance (DCR). Consider the inductor DCR as a separate
lumped quantity as shown in Figure 4. The channel current,
I L , flowing through the inductor, also passes through the
DCR. Equation 4 shows the s-domain equivalent voltage,
V L , across the inductor.
Current Sampling
During the forced off-time following a PWM transition low, the
associated channel current sense amplifier reproduces a
signal , I SEN , proportional to the inductor current, I L .
Regardless of the current sense method, I SEN is simply a
scaled version of the inductor current. Coincident with the
falling edge of the PWM signal, the sample and hold circuitry
V L = I L ? ( s ? L + DCR )
(EQ. 4)
samples I SEN . This is illustrated in Figure 5. The sample
time, t SAMP , is fixed and equal to 1/3 of the switching period,
t SW . Therefore, the sample current, I n , is proportional to the
t SAMP = ---------- = ------------------
3 ? f SW
A simple R-C network across the inductor extracts the DCR
voltage, as shown in Figure 5.
The voltage on the capacitor, V C , can be shown to be
t SW 1
3
(EQ. 7)
proportional to the channel current I L (see Equation 5).
output current and held for one switching cycle. The sample
? s ? ------------- + 1 ? ? ( DCR ? I )
V C = ---------------------------------------------------------------------
? DCR ? L
L
( s ? RC + 1 )
(EQ. 5)
current is used for current balance, load-line regulation, and
overcurrent protection.
If the R-C network components are selected such that the R-
C time constant matches the inductor L/DCR time constant,
then V C is equal to the voltage drop across the DCR.
I L
V IN
I L ( s )
PWM
L
DCR
V OUT
ISL6561
INDUCTOR
V L
C OUT
I SEN
V C (s)
PWM(n)
ISL6561 INTERNAL CIRCUIT
I n
SAMPLE
&
R
C
R ISEN
t SAMP
SAMPLE CURRENT, I n
SWITCHING PERIOD
TIME
FIGURE 5. SAMPLE AND HOLD TIMING
HOLD
ISEN-
Channel-Current Balance
I SEN = I -------------------
L R
+
-
ISEN+
DCR
ISEN
FIGURE 4. DCR SENSING CONFIGURATION
The capacitor voltage, V C , is replicated across the sense
resistor R ISEN . so that the current flowing through the sense
resistor is proportional to the inductor current. Equation 6
shows that the relationship between the channel current and
the sensed current I SEN , is driven by the value of the sense
resistor and the inductor DCR.
The sampled currents I n , from each active channel are
summed together and divided by the number of active
channels. The resulting cycle average current, I AVG ,
provides a measure of the total load current demand on the
converter during each switching cycle. Channel current
balance is achieved by comparing the sampled current of
each channel to the cycle average current, and making an
appropriate adjustment to each channel pulse width based
on the error. Intersil’s patented current-balance method is
illustrated in Figure 6, with error correction for channel 1
represented. In the figure, the cycle average current
combines with the channel 1 sample, I 1 , to create an error
signal I ER . The filtered error signal modifies the pulse width
commanded by V COMP to correct any unbalance and force
I SEN = I L ? ------------------
DCR
R ISEN
13
(EQ. 6)
I ER toward zero. The same method for error signal correction
is applied to each active channel.
FN9098.5
May 12, 2005
相关PDF资料 |
PDF描述 |
|---|---|
| ISL6563IR-T | IC CTRLR PWM MULTIPHASE 24-QFN |
| ISL6564AIRZ | IC REG CTRLR BUCK PWM VM 40-QFN |
| ISL6564IR-T | IC REG CTRLR BUCK PWM VM 40-QFN |
| ISL6565BCV-T | IC REG CTRLR BUCK PWM VM 28TSSOP |
| ISL6566AIRZ | IC CTRLR PWM 3PHASE BUCK 40-QFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL6561CRZ | 功能描述:IC CTRLR PWM MULTIPHASE 40-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| ISL6561CRZ | 制造商:Intersil Corporation 功能描述:Pulse Width Modulation (PWM) Controller |
| ISL6561CRZA | 功能描述:IC CTRLR PWM MULTIPHASE 40-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| ISL6561CRZA-T | 功能描述:IC CTRLR PWM MULTIPHASE 40-QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 专用型 系列:- 标准包装:43 系列:- 应用:控制器，Intel VR11 输入电压:5 V ~ 12 V 输出数:1 输出电压:0.5 V ~ 1.6 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:48-VFQFN 裸露焊盘 供应商设备封装:48-QFN（7x7） 包装:管件 |
| ISL6561CRZR5208 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Intersil Corporation 功能描述: |
发布紧急采购，3分钟左右您将得到回复。