参数资料
型号: ISL6569CB
厂商: Intersil
文件页数: 19/22页
文件大小: 0K
描述: IC REG CTRLR DIVIDER PWM 24-SOIC
标准包装: 30
PWM 型: 控制器
输出数: 1
频率 - 最大: 2MHz
占空比: 75%
电源电压: 4.75 V ~ 5.25 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: 0°C ~ 70°C
封装/外壳: 24-SOIC(0.295",7.50mm 宽)
包装: 管件
ISL6569
The first step is to choose the desired bandwidth, f 0 , of the
compensated system. Choose a frequency high enough to
assure adequate transient performance but not higher than
1/3 of the switching frequency. The type-III compensator has
an extra high-frequency pole, f HF . This pole can be used for
added noise rejection or to assure adequate attenuation at
the error-amplifier high-order pole and zero frequencies. A
good general rule is to chose f HF = 10 f 0 , but it can be higher
if desired. Choosing f HF to be lower than 10 f 0 can cause
problems with too much phase shift below the system
bandwidth.
C 2
resistance of the bulk output-filter capacitance; and V PP is
the peak-to-peak sawtooth signal amplitude as described in
Figure 5 and Electrical Specifications .
Input Supply Voltage Selection
The VCC input of the ISL6569 can be connected to either a
+5V supply directly or through a current limiting resistor to a
+12V supply. An integrated 5.8V shunt regulator maintains
the voltage on the VCC pin when a +12V supply is used. A
300 ? resistor is suggested for limiting the current into the
VCC pin to approximately 20mA.
Switching Frequency
There are a number of variables to consider when choosing
the switching frequency, as there are considerable effects on
R C
C C
COMP
the upper-MOSFET loss calculation. These effects are
outlined in MOSFETs , and they establish the upper limit for
the switching frequency. The lower limit is established by the
C 1
FB
requirement for fast transient response and small output-
voltage ripple as outlined in Input Supply Voltage Selection .
Choose the lowest switching frequency that allows the
R 1
R FB
IOUT
VDIFF
regulator to meet the transient-response requirements.
Switching frequency is determined by the selection of the
frequency-setting resistor, RT (see the figure Typical
Application on page 4). Figure 15 and Equation 29 are
provided to assist in the selecting the correct value for R T .
FIGURE 14. COMPENSATION CIRCUIT FOR ISL6569 BASED
CONVERTER WITHOUT LOAD-LINE
R T = 10
[ 11.09 – 1.13 log ( f S ) ]
(EQ. 29)
REGULATION.
Input Capacitor Selection
R 1 = R FB -----------------------------------------
In the solutions to the compensation equations, there is a
single degree of freedom. For the solutions presented in
Equations 28, R FB is selected arbitrarily. The remaining
compensation components are then selected according to
Equations 28.
C ( ESR )
LC – C ( ESR )
The input capacitors are responsible for sourcing the ac
component of the input current flowing into the upper
MOSFETs. Their RMS current capacity must be sufficient to
handle the ac component of the current drawn by the upper
MOSFETs which is related to duty cycle and the number of
active phases.
C 1 = -----------------------------------------
1000
LC – C ( ESR )
R FB
( 2 π ) 2 f 0 f HF LCR FB V PP
V PP ? 2 π ? f 0 f HF LCR FB
R C = ---------------------------------------------------------------------
? 2 π f
HF LC – 1 ?
?
0.75 V
0.75V IN
C 2 = -------------------------------------------------------------------
2
? ?
?
IN
(EQ. 28)
100
0.75V IN ? 2 π f
( 2 π ) 2 f 0 f HF LCR FB V PP
?
? HF LC – 1 ?
C C = -------------------------------------------------------------------
10
10
100 1000
10000
In Equations 28, L is the per-channel filter inductance
divided by the number of active channels; C is the sum total
of all output capacitors; ESR is the equivalent-series
19
SWITCHING FREQUENCY (KHZ)
FIGURE 15. R T VS SWITCHING FREQUENCY
FN9085.7
December 29, 2004
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ISL6569CB-T 功能描述:IC REG CTRLR DIVIDER PWM 24-SOIC RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:100% 电源电压:8.2 V ~ 30 V 降压:无 升压:无 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:0°C ~ 70°C 封装/外壳:8-DIP(0.300",7.62mm) 包装:管件 产品目录页面:1316 (CN2011-ZH PDF)
ISL6569CBZ 功能描述:IC REG CTRLR DIVIDER PWM 24-SOIC 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)
ISL6569CBZ-T 功能描述:IC REG CTRLR DIVIDER PWM 24-SOIC 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)
ISL6569CR 功能描述:IC REG CTRLR DIVIDER PWM 32-QFN RoHS:否 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 切换控制器 系列:- 标准包装:2,500 系列:- PWM 型:电流模式 输出数:1 频率 - 最大:500kHz 占空比:100% 电源电压:8.2 V ~ 30 V 降压:无 升压:无 回扫:是 反相:无 倍增器:无 除法器:无 Cuk:无 隔离:是 工作温度:0°C ~ 70°C 封装/外壳:8-DIP(0.300",7.62mm) 包装:管件 产品目录页面:1316 (CN2011-ZH PDF)
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