- 您现在的位置：买卖IC网 > PDF目录44546 > LM25066PSQX (NATIONAL SEMICONDUCTOR CORP) POWER SUPPLY SUPPORT CKT, QCC24 PDF资料下载
参数资料
| 型号： | LM25066PSQX |
| 厂商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分类： | 电源管理 |
| 英文描述： | POWER SUPPLY SUPPORT CKT, QCC24 |
| 封装： | LLP-24 |
| 文件页数： | 6/48页 |
| 文件大小： | 1456K |
| 代理商： | LM25066PSQX |
第1页第2页第3页第4页第5页当前第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页
30115813
FIGURE 2. Power Up Sequence (Current Limit Only)
Gate Control
A charge pump provides the voltage at the GATE pin to en-
hance the N-Channel MOSFET’s gate. During normal oper-
ating conditions (t
by an internal 22 A current source. The voltage at the GATE
pin (with respect to ground) is limited by an internal 18.8 V
zener diode. See the graph “GATE Pin Voltage” shown pre-
viously. Since the gate-to-source voltage applied to Q
1 could
be as high as 18.8 V during various conditions, a zener diode
with the appropriate voltage rating must be added between
the GATE and OUT pins if the maximum V
GS rating of the
selected MOSFET is less than 18.8 V. The external zener
diode must have a forward current rating of at least 190 mA.
When the system voltage is initially applied, the GATE pin is
held low by a 190 mA pull-down current. This helps prevent
an inadvertent turn-on of the MOSFET through its drain-gate
capacitance as the applied system voltage increases.
During the insertion time (t
1 in Figure 2) the GATE pin is held
low by a 2 mA pull-down current. This maintains Q
1 in the off-
state until the end of t
1, regardless of the voltage at VIN or
UVLO. Following the insertion time (t
2 in Figure 2), the gate
voltage of Q
1 is controlled to keep the current or power dissi-
pation level from exceeding the programmed levels. While in
the current or power limiting mode, the TIMER pin capacitor
is charging. If the current and power limiting cease before the
TIMER pin reaches 1.7V, the TIMER pin capacitor then dis-
charges, and the circuit begins normal operation. If the inrush
limiting condition persists such that the TIMER pin reached
1.7V during t
2, the GATE pin is then pulled low by the 190 mA
pull-down current. The GATE pin is then held low until either
a power up sequence is initiated (RETRY pin to VDD), or an
automatic retry is attempted (RETRY pin to GROUND). See
the Fault Timer & Restart section. If the system input voltage
falls below the UVLO threshold or rises above the OVLO
threshold, the GATE pin is pulled low by the 2 mA pull-down
current to switch off Q
1.
Current Limit
The current limit threshold is reached when the voltage across
the sense resistor R
S (VIN to SENSE) exceeds the internal
voltage limit of 25 mV or 46 mV depending on whether the CL
pin is connected to GND or VDD, respectively. In the current
limiting condition, the GATE voltage is controlled to limit the
current in MOSFET Q
1. While the current limit circuit is active,
the fault timer is active as described in the Fault Timer &
Restart section. If the load current falls below the current limit
threshold before the end of the Fault Timeout Period, the
LM25066 resumes normal operation. If the current limit con-
dition persists for longer than the Fault Timeout Period set by
the timer capacitor, C
T, the IIN OC FAULT bit in the
www.national.com
14
LM25066
相关PDF资料 |
PDF描述 |
|---|---|
| LM25066PSQ | POWER SUPPLY SUPPORT CKT, QCC24 |
| LM25574Q0MT | SWITCHING REGULATOR, PDSO16 |
| LM25574Q0MTX | SWITCHING REGULATOR, PDSO16 |
| LM25576Q0MH | SWITCHING REGULATOR, PDSO20 |
| LM2574HVADJMWC | 1.8 A SWITCHING REGULATOR, 63 kHz SWITCHING FREQ-MAX, UUC |
相关代理商/技术参数 |
参数描述 |
|---|---|
| LM25066PSQX/NOPB | 功能描述:热插拔功率分布 RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube |
| LM25069 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:Positive Low Voltage Power Limiting Hot Swap Controller |
| LM25069MM-2EVAL | 功能描述:BOARD EVALUATION LM25069 RoHS:是 类别:编程器，开发系统 >> 评估演示板和套件 系列:- 标准包装:1 系列:PCI Express® (PCIe) 主要目的:接口，收发器，PCI Express 嵌入式:- 已用 IC / 零件:DS80PCI800 主要属性:- 次要属性:- 已供物品:板 |
| LM25069MM-2EVAL/NOPB | 功能描述:电源管理IC开发工具 LM25069MM-2 Eval Brd RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| LM25069PMM-1 | 制造商:NSC 制造商全称:National Semiconductor 功能描述:Positive Low Voltage Power Limiting Hot Swap Controller |
发布紧急采购，3分钟左右您将得到回复。