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参数资料
| 型号： | ISL8502AEVAL1Z |
| 厂商： | Intersil |
| 文件页数： | 14/20页 |
| 文件大小： | 0K |
| 描述： | EVAL BOARD FOR ISL8502 |
| 标准包装： | 1 |
| 主要目的： | DC/DC，步降 |
| 输出及类型： | 2，非隔离 |
| 输出电压： | 4.4V |
| 电流 - 输出： | 2A |
| 输入电压： | 5V，5.5 ~ 14 V |
| 稳压器拓扑结构： | 降压 |
| 频率 - 开关： | 500kHz ~ 1.2MHz |
| 板类型： | 完全填充 |
| 已供物品： | 板，文档 |
| 已用 IC / 零件： | ISL8502 |
ISL8502A
Stand-alone Operation
The ISL8502A can be configured to function as a stand-alone
single channel voltage mode synchronous buck PWM voltage
regulator. The “Typical Application Schematics” on page 4 show
the two configurations for stand-alone operation.
The internal series linear regulator requires at least 5.5V to
create the proper bias for the IC. If the input voltage is between
5.5V and 15V, simply connect the VIN pins to the input rail, and
the series linear regulator creates the bias for the IC. The VCC pin
should be tied to a capacitor for decoupling.
If the input voltage is 5V ± 10%, then tie the VIN pins and the VCC
pin to the input rail. The ISL8502A uses the 5V rail as the bias. A
decoupling capacitor should be placed as close as possible to the
VCC pin.
Multi-Channel (Master/Slave) Operation
The ISL8502A can be configured to function in a multi-channel
shows a typical configuration for the multi-channel system.
In the multi-channel system, each ISL8502A IC regulates a
separate rail while sharing the same input rail. By configuring the
devices in a master/slave configuration, the clocks of each IC
can be synchronized.
There can only be one master IC in a multi-channel system. To
configure an IC as the master, the M/S pin must be shorted to
the VCC pin. The SYNCH pins of all the ISL8502A controller ICs in
the multi-channel system must be tied together. The frequency
set resistor value (R T ) used on the master device must be used
on every slave device. Each slave device must have a 5k Ω
resistor connecting it from M/S pin to ground.
The master device and all slave devices can have their EN pins tied
to an enable “bus.” Since the EN pin is bi-directional, it allows for
options on how each IC is tied to the enable bus. If the EN pin of any
ISL8502A is tied directly to the enable bus, then that device is
capable of disabling all the other devices that have their EN pins tied
directly to the enable bus. If the EN pin of an ISL8502A is tied to the
enable bus through a diode (anode tied to ISL8502A EN pin,
cathode tied to enable bus), then the part does not disable other
devices on the enable bus if it disables itself for any reason.
If the master device is disabled via the EN pin, it continues to
send the clock signal from the SYNCH pin. This allows slave
devices to continue operating.
Fault Protection
Overcurrent Condition Flag is set from LOW to HIGH. If, on the
subsequent cycle, another overcurrent condition is detected, the
OC Fault Counter is incremented. If there are eight sequential OC
fault detections, the regulator is shut down under an Overcurrent
Fault Condition, and the EN pin is pulled LOW. An Overcurrent
Fault Condition results, with the regulator attempting to restart in
hiccup mode. The delay between restarts is four soft-start
periods. At the end of the fourth soft-start wait period, the fault
counters are reset, the EN pin is released, and soft-start is
attempted again. If the overcurrent condition goes away prior to
the OC Fault Counter reaching a count of four, the Overcurrent
Condition Flag is set back to LOW.
If the Overcurrent Condition Flag is HIGH, the Overcurrent Fault
Counter is less than four, and an undervoltage event is detected,
the regulator shuts down immediately.
UNDERVOLTAGE PROTECTION
If the voltage detected on the FB pin falls 18% below the internal
reference voltage, and if the overcurrent condition flag is LOW,
then the regulator is shut down immediately under an
Undervoltage Fault Condition, and the EN pin is pulled LOW. An
Undervoltage Fault Condition results in the regulator attempting
to restart in hiccup mode, with the delay between restarts being
four soft-start periods. At the end of the fourth soft-start wait
period, the fault counters are reset, the EN pin is released, and
soft-start is attempted again.
THERMAL PROTECTION
If the ISL8502A IC junction temperature reaches a nominal
temperature of +150°C, the regulator is disabled. The ISL8502A
does not re-enable the regulator until the junction temperature
drops below +130°C.
SHOOT-THROUGH PROTECTION
A shoot-through condition occurs when both the upper and lower
MOSFETs are turned on simultaneously, effectively shorting the
input voltage to ground. To protect from a shoot-through
condition, the ISL8502A incorporates specialized circuitry, which
ensures that the complementary MOSFETs are not ON
simultaneously.
Application Guidelines
Operating Frequency
The ISL8502A can operate at switching frequencies from
500kHz to 1.2MHz. A resistor tied from the FS pin to ground is
used to program the switching frequency (Equation 3).
R T [ k Ω ] = ------------------------------
The ISL8502A monitors the output of the regulator for overcurrent
and undervoltage events. The ISL8502A also provides protection
from excessive junction temperatures.
48000
f OSC [ kHz ]
(EQ. 3)
OVERCURRENT PROTECTION
The overcurrent function protects the switching converter from a
shorted output by monitoring the current flowing through both the
upper and lower MOSFETs.
Upon detection of any overcurrent condition, the upper MOSFET
is immediately turned off and is not turned on again until the
next switching cycle. Upon detection of the initial overcurrent
condition, the Overcurrent Fault Counter is set to 1, and the
14
Output Voltage Selection
The output voltage of the regulator can be programmed via an
external resistor divider that is used to scale the output voltage
relative to the internal reference voltage and feed it back to the
inverting input of the error amplifier (see Figure 36).
The output voltage programming resistor, R 4 , depends on the
value chosen for the feedback resistor and the desired output
FN7940.0
October 21, 2011
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| ISL8502AIRZ | 功能描述:IC REG BUCK SYNC ADJ 2A 24QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:两者兼有 输出数:1 输出电压:5V，1 V ~ 10 V 输入电压:3.5 V ~ 28 V PWM 型:电流模式 频率 - 开关:220kHz ~ 1MHz 电流 - 输出:600mA 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:16-SSOP（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:16-QSOP |
| ISL8502AIRZ-T | 功能描述:IC REG BUCK SYNC ADJ 2A 24QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:两者兼有 输出数:1 输出电压:5V，1 V ~ 10 V 输入电压:3.5 V ~ 28 V PWM 型:电流模式 频率 - 开关:220kHz ~ 1MHz 电流 - 输出:600mA 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:16-SSOP（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:16-QSOP |
| ISL8502AIRZ-TR5194 | 制造商:Intersil Corporation 功能描述:PACHINKO INTEGRATED FET SYNCH BUCK - 4X4 24LD QFN, T&R - Tape and Reel 制造商:Intersil Corporation 功能描述:IC REG BUCK SYNC ADJ 2A 24QFN |
| ISL8502EVAL1Z | 功能描述:EVALUATION BOARD FOR ISL8502 RoHS:是 类别:编程器，开发系统 >> 评估板 - DC/DC 与 AC/DC（离线）SMPS 系列:- 产品培训模块:Obsolescence Mitigation Program 标准包装:1 系列:True Shutdown™ 主要目的:DC/DC，步升 输出及类型:1，非隔离 功率 - 输出:- 输出电压:- 电流 - 输出:1A 输入电压:2.5 V ~ 5.5 V 稳压器拓扑结构:升压 频率 - 开关:3MHz 板类型:完全填充 已供物品:板 已用 IC / 零件:MAX8969 |
| ISL8502IRZ | 功能描述:IC REG BUCK SYNC ADJ 2.5A 24QFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 类型:降压（降压） 输出类型:两者兼有 输出数:1 输出电压:5V，1 V ~ 10 V 输入电压:3.5 V ~ 28 V PWM 型:电流模式 频率 - 开关:220kHz ~ 1MHz 电流 - 输出:600mA 同步整流器:无 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:16-SSOP（0.154"，3.90mm 宽） 包装:带卷 (TR) 供应商设备封装:16-QSOP |
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