- 您现在的位置：买卖IC网 > PDF目录15147 > MAX5974EETE+ (Maxim Integrated Products)IC REG CTRLR FLYBACK PWM 16-TQFN PDF资料下载
参数资料
| 型号： | MAX5974EETE+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 17/22页 |
| 文件大小： | 0K |
| 描述： | IC REG CTRLR FLYBACK PWM 16-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 1 |
| PWM 型： | 电流模式 |
| 输出数： | 1 |
| 频率 - 最大： | 600kHz |
| 占空比： | 82% |
| 降压： | 无 |
| 升压： | 无 |
| 回扫： | 是 |
| 反相： | 无 |
| 倍增器： | 无 |
| 除法器： | 无 |
| Cuk： | 无 |
| 隔离： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 封装/外壳： | 16-WFQFN 裸露焊盘 |
| 包装： | 管件 |
MAX5974E/MAX5974F
Current-Mode PWM Controllers for
Low-Cost Flyback Supplies
BLANKING, t BLK
NDRV
AUXDRV
DEAD TIME, t DT
Figure 5. Dead Time Between AUXDRV and NDRV
8.7 × 10 9
R RT =
R CS =
Oscillator/Switching Frequency
The ICs’ switching frequency is programmable between
100kHz and 600kHz with resistor R RT connected
between RT and GND. Use the following formula to
determine the appropriate value of R RT needed to gen-
erate the desired output-switching frequency (f SW ):
f SW
where f SW is the desired switching frequency.
Peak Current Limit
The current-sense resistor (R CS in the Typical
Application Circuit ), connected between the source
of the n-channel MOSFET and PGND, sets the current
limit. The current-limit comparator has a voltage trip level
(V CS-PEAK ) of 400mV. Use the following equation to cal-
culate the value of R CS :
400mV
I PRI
where I PRI is the peak current in the primary side of
the transformer, which also flows through the MOSFET.
When the voltage produced by this current (through the
current-sense resistor) exceeds the current-limit com-
parator threshold, the MOSFET driver (NDRV) terminates
the current on-cycle, within 35ns (typ).
Maxim Integrated
The devices implement 115ns of leading-edge blanking
to ignore leading-edge current spikes. These spikes
are caused by reflected secondary currents, current-
discharging capacitance at the FET’s drain, and gate-
charging current. Use a small RC network for additional
filtering of the leading-edge spike on the sense wave-
form when needed. Set the corner frequency between
10MHz and 20MHz.
After the leading-edge blanking time, the device moni-
tors V CS for any breaches of the peak current limit of
400mV. The duty cycle is terminated immediately when
V CS exceeds 400mV.
Output Short-Circuit Protection
with Hiccup Mode
When the device detects eight consecutive peak current-
limit events, both NDRV and AUXDRV driver outputs are
turned off for a restart period, t RSTRT . After t RSTRT , the
device undergoes soft-start. The duration of the restart
period depends on the value of the capacitor at SS (C SS ).
During this period, C SS is discharged with a pulldown cur-
rent of I SS-DH (2 F A typ). Once its voltage reaches 0.15V,
the restart period ends and the device initiates a soft-start
sequence. An internal counter ensures that the minimum
restart period (t RSTRT-MIN ) is 1024 clock cycles when the
time required for C SS to discharge to 0.15V is less than
1024 clock cycles. Figure 6 shows the behavior of the
device prior and during hiccup mode.
17
相关PDF资料 |
PDF描述 |
|---|---|
| GBC60DCSD | CONN EDGECARD 120PS DIP .100 SLD |
| MAX5974DETE+ | IC REG CTRLR FLYBACK PWM 16-TQFN |
| EEC65DRYS | CONN EDGECARD 130PS DIP .100 SLD |
| MAX5974CETE+ | IC REG CTRLR FLYBACK PWM 16-TQFN |
| MAX669EUB/V+T | IC REG CTRLR PWM HYBRID 10-UMAX |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX5974EETE+ | 功能描述:电流型 PWM 控制器 Current-Mode PWM Controller RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX5974EETE+T | 功能描述:电流型 PWM 控制器 Current-Mode PWM Controller RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX5974EEVKIT# | 功能描述:电流型 PWM 控制器 MAX5974E Eval Kit RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX5974FETE+ | 功能描述:电流型 PWM 控制器 Current-Mode PWM Controller RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
| MAX5974FETE+T | 功能描述:电流型 PWM 控制器 Current-Mode PWM Controller RoHS:否 制造商:Texas Instruments 开关频率:27 KHz 上升时间: 下降时间: 工作电源电压:6 V to 15 V 工作电源电流:1.5 mA 输出端数量:1 最大工作温度:+ 105 C 安装风格:SMD/SMT 封装 / 箱体:TSSOP-14 |
发布紧急采购，3分钟左右您将得到回复。