参数资料
型号: ISL6521CBZA
厂商: Intersil
文件页数: 10/13页
文件大小: 639K
描述: IC REG QD BCK/LINEAR 16-SOIC
标准包装: 480
拓扑: 降压(降压)同步(1),线性(LDO)(3)
功能: 任何功能
输出数: 4
频率 - 开关: 300kHz
电压/电流 - 输出 1: 控制器
电压/电流 - 输出 2: 可调式,120mA
电压/电流 - 输出 3: 可调式,120mA
带 LED 驱动器:
带监控器:
带序列发生器:
电源电压: 4.5 V ~ 5.5 V
工作温度: 0°C ~ 70°C
安装类型: *
封装/外壳: 16-SOIC(0.154",3.90mm 宽)
供应商设备封装: *
包装: 管件
10
Component Selection Guidelines
Output Capacitor Selection
The output capacitors for each output have unique
requirements. In general, the output capacitors should be
selected to meet the dynamic load regulation requirements.
Additionally, the PWM converters require an output capacitor
to filter the current ripple. The load transient for some
embedded processors requires high quality capacitors to
supply the high slew rate (di/dt) current demands.
PWM Output Capacitors
High performance embedded processors can produce
transient load rates above 1A/ns. High frequency capacitors
initially supply the transient current and slow the load rate-of-
change seen by the bulk capacitors. The bulk filter capacitor
values are generally determined by the ESR (effective series
resistance) and voltage rating requirements rather than
actual capacitance requirements.
High frequency decoupling capacitors should be placed as
close to the power pins of the load as physically possible. Be
careful not to add inductance in the circuit board wiring that
could cancel the usefulness of these low inductance
components. Consult with the manufacturer of the load on
specific decoupling requirements.
Use only specialized low-ESR capacitors intended for
switching-regulator applications for the bulk capacitors. The
bulk capacitors ESR determines the output ripple voltage
and the initial voltage drop following a high slew-rate
transients edge. An aluminum electrolytic capacitors ESR
value is related to the case size with lower ESR available in
larger case sizes. However, the equivalent series inductance
(ESL) of these capacitors increases with case size and can
reduce the usefulness of the capacitor to high slew-rate
transient loading. Unfortunately, ESL is not a specified
parameter. Work with your capacitor supplier and measure
the capacitors impedance with frequency to select a suitable
component. In most cases, multiple electrolytic capacitors of
small case size perform better than a single large case
capacitor.
Linear Output Capacitors
The output capacitors for the linear regulators provide
dynamic load current. The linear controllers use dominant
pole compensation integrated into the error amplifier and are
insensitive to output capacitor selection. Output capacitors
should be selected for transient load regulation.
PWM Output Inductor Selection
The PWM converter requires an output inductor. The output
inductor is selected to meet the output voltage ripple
requirements and sets the converters response time to a
load transient. The inductor value determines the converters
ripple current and the ripple voltage is a function of the ripple
current. The ripple voltage and current are approximated by
the following equations:
Increasing the value of inductance reduces the ripple current
and voltage. However, the large inductance values increase
the converters response time to a load transient.
One of the parameters limiting the converters response to a
load transient is the time required to change the inductor
current. Given a sufficiently fast control loop design, the
ISL6521 will provide either 0% or 100% duty cycle in
response to a load transient. The response time is the time
interval required to slew the inductor current from an initial
current value to the post-transient current level. During this
interval the difference between the inductor current and the
transient current level must be supplied by the output
capacitor(s). Minimizing the response time can minimize the
output capacitance required.
The response time to a transient is different for the
application of load and the removal of load. The following
equations give the approximate response time interval for
application and removal of a transient load:
where: I
TRAN
 is the transient load current step, t
RISE
 is the
response time to the application of load, and t
FALL
 is the
response time to the removal of load. Be sure to check both
of these equations at the minimum and maximum output
levels for the worst case response time.
Input Capacitor Selection
The important parameters for the bulk input capacitors are
the voltage rating and the RMS current rating. For reliable
operation, select bulk input capacitors with voltage and
current ratings above the maximum input voltage and largest
RMS current required by the circuit. The capacitor voltage
rating should be at least 1.25 times greater than the
maximum input voltage and a voltage rating of 1.5 times is a
conservative guideline. The RMS current rating requirement
for the input capacitor of a buck regulator is approximately
1/2 of the summation of the DC load current.
Use a mix of input bypass capacitors to control the voltage
overshoot across the MOSFETs. Use ceramic capacitance
for the high frequency decoupling and bulk capacitors to
supply the RMS current. Small ceramic capacitors can be
placed very close to the upper MOSFET to suppress the
voltage induced in the parasitic circuit impedances.
For a through-hole design, several electrolytic capacitors
may be needed. For surface mount designs, solid tantalum
capacitors can be used, but caution must be exercised with
regard to the capacitor surge current rating. These
capacitors must be capable of handling the surge-current at
power-up.
I
V
IN
V
OUT

F
S
L
?/DIV>
--------------------------------
V
OUT
V
IN
----------------
?/DIV>
=
V
OUT

I
  ESR
?/DIV>
=
t
RISE
L
O
I
TRAN
?/DIV>
V
IN
V
OUT

--------------------------------
=
t
FALL
L
O
I
TRAN
?/DIV>
V
OUT
-------------------------------
=
ISL6521
相关PDF资料
PDF描述
GBM12DSEI-S13 CONN EDGECARD 24POS .156 EXTEND
RGP10ME-E3/54 DIODE GPP 1A 1000V 500NS DO-41
ISL6521CBZ IC REG QD BCK/LINEAR SYNC 16SOIC
EEC18DRTN-S13 CONN EDGECARD 36POS .100 EXTEND
RMA44DRST-S288 CONN EDGECARD 88POS .125 EXTEND
相关代理商/技术参数
参数描述
ISL6521CBZA-T 功能描述:电压模式 PWM 控制器 W/ANNEAL 4 IN 1 PWM/ LINEAR CNTRLR 5V RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel
ISL6521CBZS2698 功能描述:IC REG QD BCK/LINEAR 16-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 + 切换式 系列:- 标准包装:2,500 系列:- 拓扑:降压(降压)同步(3),线性(LDO)(2) 功能:任何功能 输出数:5 频率 - 开关:300kHz 电压/电流 - 输出 1:控制器 电压/电流 - 输出 2:控制器 电压/电流 - 输出 3:控制器 带 LED 驱动器:无 带监控器:无 带序列发生器:是 电源电压:5.6 V ~ 24 V 工作温度:-40°C ~ 85°C 安装类型:* 封装/外壳:* 供应商设备封装:* 包装:*
ISL6521CBZ-T 功能描述:电压模式 PWM 控制器 4 IN 1 PWM/LINEAR CNTRLR 5V RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel
ISL6521CBZ-TS2698 功能描述:IC REG QD BCK/LINEAR 16-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - 线性 + 切换式 系列:- 标准包装:2,500 系列:- 拓扑:降压(降压)同步(3),线性(LDO)(2) 功能:任何功能 输出数:5 频率 - 开关:300kHz 电压/电流 - 输出 1:控制器 电压/电流 - 输出 2:控制器 电压/电流 - 输出 3:控制器 带 LED 驱动器:无 带监控器:无 带序列发生器:是 电源电压:5.6 V ~ 24 V 工作温度:-40°C ~ 85°C 安装类型:* 封装/外壳:* 供应商设备封装:* 包装:*
ISL6521EVAL1 功能描述:EVALUATION BOARD 1 ISL6521 RoHS:否 类别:编程器,开发系统 >> 过时/停产零件编号 系列:- 标准包装:1 系列:- 传感器类型:CMOS 成像,彩色(RGB) 传感范围:WVGA 接口:I²C 灵敏度:60 fps 电源电压:5.7 V ~ 6.3 V 嵌入式:否 已供物品:成像器板 已用 IC / 零件:KAC-00401 相关产品:4H2099-ND - SENSOR IMAGE WVGA COLOR 48-PQFP4H2094-ND - SENSOR IMAGE WVGA MONO 48-PQFP