参数资料
型号: ISL8845AMBZ
厂商: Intersil
文件页数: 13/15页
文件大小: 0K
描述: IC REG CTRLR BST FLYBK ISO 8SOIC
标准包装: 980
PWM 型: 电流模式
输出数: 1
频率 - 最大: 2MHz
占空比: 50%
电源电压: 9 V ~ 30 V
降压:
升压:
回扫:
反相:
倍增器:
除法器:
Cuk:
隔离:
工作温度: -55°C ~ 125°C
封装/外壳: 8-SOIC(0.154",3.90mm 宽)
包装: 管件
ISL8840A, ISL8841A, ISL8842A, ISL8843A, ISL8844A, ISL8845A
Example:
V IN = 12V
V O = 48V
L s = 800 μ H
Ns/Np = 10
Lp = 8.0 μ H
I O = 200mA
Switching Frequency, f sw = 200kHz
Duty Cycle, D = 28.6%
R 6 = 499 Ω
Solve for the current sense resistor, R CS , using Equation 15.
R CS = 295m Ω
Determine the amount of voltage, Ve, that must be added to
the current feedback signal using Equation 12.
Ve = 92.4mV
Using Equation 17, solve for the summing resistor, R 9 , from
CT to CS.
R 9 = 2.67k Ω
Determine the new value of R CS (R’ CS ) using Equation 18.
R’ CS = 350m Ω
Additional slope compensation may be considered for
design margin. The above discussion determines the
minimum external ramp that is required. The buffer transistor
used to create the external ramp from RTCT should have a
sufficiently high gain (>200) so as to minimize the required
base current. Whatever base current is required reduces the
charging current into RTCT and will reduce the oscillator
frequency.
13
Fault Conditions
A Fault condition occurs if VREF falls below 4.65V. When a
Fault is detected OUT is disabled. When VREF exceeds
4.80V, the Fault condition clears, and OUT is enabled.
Ground Plane Requirements
Careful layout is essential for satisfactory operation of the
device. A good ground plane must be employed. A unique
section of the ground plane must be designated for high di/dt
currents associated with the output stage. V DD should be
bypassed directly to GND with good high frequency
capacitors.
References
[1] Ridley, R., “A New Continuous-Time Model for Current
Mode Control”, IEEE Transactions on Power
Electronics, Vol. 6, No. 2, April 1991.
FN6320.3
April 18, 2007
相关PDF资料
PDF描述
GCC40DREF CONN EDGECARD 80POS .100 EYELET
ISL8845AMUZ IC REG CTRLR BST FLYBK ISO 8MSOP
GSC19DRAN CONN EDGECARD 38POS R/A .100 SLD
ISL8843AABZ IC REG CTRLR BST FLYBK ISO 8SOIC
GMC19DRAN CONN EDGECARD 38POS R/A .100 SLD
相关代理商/技术参数
参数描述
ISL8845AMBZ-T 功能描述:IC REG CTRLR BST FLYBK ISO 8SOIC 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)
ISL8845AMUZ 功能描述:IC REG CTRLR BST FLYBK ISO 8MSOP 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)
ISL8845AMUZ-T 功能描述:IC REG CTRLR BST FLYBK ISO 8MSOP 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)
ISL88550AEVAL1 功能描述:EVALUATION BOARD 1 ISL88550A 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
ISL88550AEVAL1Z 功能描述:EVALUATION BOARD 1 ISL88550A 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