参数资料
| 型号： | ISL78225ANEZ-T |
| 厂商： | Intersil |
| 文件页数： | 19/22页 |
| 文件大小： | 0K |
| 描述： | IC PWM CONTROLLER |
| 标准包装： | 1,000 |
| 系列： | * |
ISL78225
However, during the phase adding period, the individual channel
current protection function will be blanked for 200μs, in order to
give other phases the chance to take care of the current.
The IOUT pin serves for both input current monitoring and total
average current OCP functions. The CSA output current for each
channel is scaled and summed together at this pin. An RC
network should be connected between the IOUT pin and GND,
such that the ripple current signal can be filtered out and
converted to a voltage signal to represent the averaged total
input current. The relationship between total input current I IN and
V IOUT can be calculated as Equation 10 (see Figure 20 on
200
180
160
140
120
100
80
60
40
20
T A = +100°C
T A = +25°C
T A = +50°C
T A = +75°C
R SEN
R
V IOUT = 0.75I IN -------------- R IOUT
SET
(EQ. 10)
0
6
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40
V IN (V)
R IOUT = ----------------------------
(EQ. 11)
When the V IOUT is higher than 2V for a consecutive 100μs, the
ISL78225 IC will be triggered to shut down. This provides
additional safety for the voltage regulator.
Equation 11 can be used to calculate the value of the resistor R IOUT
based on the desired OCP level I AVG, OCP2 .
2
I AVG , OCP2
The total average overcurrent protection scheme will not be
asserted until the soft-start pin voltage V SS reaches its clamped
value (approximately 3.5V). During the soft-start time, the system
does not latch-off if per-channel or overall OC limit is reached.
Instead, the individual channel current will run at its pre-set peak
current limit level.
Thermal Protection
The ISL78225 will be disabled if the die junction temperature
reaches a nominal of +160°C. It will recover when the junction
temperature falls below a +15°C hysteresis. The +15°C
hysteresis insures that the device will not be re-enabled until the
junction temperature has dropped to below about +145°C.
Internal 5V LDO Output Current
Limit Derating Curves
ISL78225 contains an internal 5V/200mA LDO, and the input of
LDO (VIN pin) can go as high as 40V. Based on the junction to
ambient thermal resistance R JA of the package, we need to
guarantee that the maximum junction temperature should be
FIGURE 22. I LDO(MAX) vs V IN
Dedicated VREF2 Pin for Input
Voltage Tracking
A second reference input pin, VREF2, is added to the input of the
transconductance amplifier. The ISL78225 internal reference will
automatically change to VREF2 when it is pulled below 1.8V. The
VREF2 pin can be connected to VIN through resistor network to
implement the automatic input voltage tracking function. This
function is very useful under car battery voltage cranking
conditions (such as when the car is parked and the driver is
listening to the stereo), where the full load power is typically not
needed. In this case, the ISL78225 can limit the output power by
allowing the output voltage to track the input voltage. If VREF2 is
not used, the pin should be connected to VCC.
Configurations for Dual IC
Operations
For high power applications, two ISL78225 ICs can be easily
configured to support 8-phase operation. The IC that provides the
CLK_OUT signal is called master IC, and the IC that received the
CLK_OUT signal is called slave IC. Note that the two PWM1
signals are synchronized and the net effect is 4-phase operation
with double the output current.
SYSTEM
DRIVE_EN
below +125°C T MAX . Figure 22 shows the relationship between
maximum allowed LDO output current and input voltage. The curve
DRIVE_EN
DRIVE_EN
is based on +35°C/W thermal resistance R JA for the package.
Each curve represents different ambient temperature, T A .
CLK_OUT
MASTER IC
SYNC
SLAVE IC
COMP
FB
SS
COMP
FB
SS
FIGURE 23. CONFIGURATIONS FOR DUAL IC OPERATION
19
FN7909.3
February 11, 2014
相关PDF资料 |
PDF描述 |
|---|---|
| ISL78228ARZ | IC REG BUCK SYNC ADJ DL 10-DFN |
| ISL78301FVEAZ | IC REG LDO 3.3V .15A 14HTSSOP |
| ISL78302AARBJZ | IC REG LDO 1.5V/2.8V .3A 10DFN |
| ISL78307FBECZ | IC REG LDO ADJ 50MA 8SOIC |
| ISL78310ARAJZ | IC REG LDO ADJ 1A 10DFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| ISL78225EVAL1Z | 制造商:Intersil Corporation 功能描述:ISL78225 EVALUATION BOARD 1 - 44 LEAD - TQFP - ROHS COMPLIAN - Bulk |
| ISL78228 | 制造商:INTERSIL 制造商全称:Intersil Corporation 功能描述:Dual 800mA Low Quiescent Current 2.25MHz High Efficiency Synchronous Buck Regulator |
| ISL78228ARZ | 功能描述:IC REG BUCK SYNC ADJ DL 10-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:4.5V 输入电压:2.65 V ~ 4.35 V PWM 型:电流模式 频率 - 开关:3.5MHz 电流 - 输出:800mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:9-UFBGA，DSBGA 包装:Digi-Reel® 供应商设备封装:9-DSBGA（1.2x1.3） 其它名称:296-29764-6 |
| ISL78228ARZ-T | 功能描述:IC REG BUCK SYNC ADJ DL 10-DFN RoHS:是 类别:集成电路 (IC) >> PMIC - 稳压器 - DC DC 开关稳压器 系列:- 标准包装:1 系列:- 类型:升压（升压） 输出类型:固定 输出数:1 输出电压:4.5V 输入电压:2.65 V ~ 4.35 V PWM 型:电流模式 频率 - 开关:3.5MHz 电流 - 输出:800mA 同步整流器:是 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:9-UFBGA，DSBGA 包装:Digi-Reel® 供应商设备封装:9-DSBGA（1.2x1.3） 其它名称:296-29764-6 |
| ISL78233ARZ | 制造商:Intersil Corporation 功能描述:IC REG BUCK SYNC ADJ 3A 16QFN |
发布紧急采购，3分钟左右您将得到回复。