- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385481 > LM3478 (National Semiconductor Corporation) High Efficiency Low-Side N-Channel Controller for Switching Regulator PDF資料下載
參數(shù)資料
| 型號： | LM3478 |
| 廠商： | National Semiconductor Corporation |
| 英文描述： | High Efficiency Low-Side N-Channel Controller for Switching Regulator |
| 中文描述： | 高效率低側(cè)N溝道開關(guān)穩(wěn)壓器控制器 |
| 文件頁數(shù)： | 10/21頁 |
| 文件大小： | 624K |
| 代理商： | LM3478 |
Functional Description
(Continued)
SLOPE COMPENSATION RAMP
The LM3478 uses a current mode control scheme. The main
advantages of current mode control are inherent cycle-by-
cycle current limit for the switch, and simpler control loop
characteristics. It is also easy to parallel power stages using
current mode control since current sharing is automatic.
Current mode control has an inherent instability for duty
cycles greater than 50%, as shown in
Figure 2
. In
Figure 2
,
a small increase in the load current causes the switch cur-
rent to increase by
I
O
. The effect of this load change,
I
1
, is
:
From the above equation, when D
>
0.5,
I
will be greater
than
I
. In other words, the disturbance is divergent. So a
very small perturbation in the load will cause the disturbance
to increase.
To prevent the sub-harmonic oscillations, a compensation
ramp is added to the control signal, as shown in
Figure 3
.
With the compensation ramp,
10135507
FIGURE 1. Basic Operation of the PWM comparator
10135509
FIGURE 2. Sub-Harmonic Oscillation for D
>
0.5
L
www.national.com
10
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM3478MM | High Efficiency Low-Side N-Channel Controller for Switching Regulator |
| LM3478MMX | High Efficiency Low-Side N-Channel Controller for Switching Regulator |
| LM3485 | Hysteretic PFET Buck Controller |
| LM3485MM | Hysteretic PFET Buck Controller |
| LM3485MMX | Hysteretic PFET Buck Controller |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM3478_09 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:High Efficiency Low-Side N-Channel Controller for Switching Regulator |
| LM3478EVAL | 功能描述:BOARD EVALUATION LM3478 RoHS:否 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - DC/DC 與 AC/DC（離線）SMPS 系列:- 產(chǎn)品培訓(xùn)模塊:Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:1 系列:True Shutdown™ 主要目的:DC/DC，步升 輸出及類型:1，非隔離 功率 - 輸出:- 輸出電壓:- 電流 - 輸出:1A 輸入電壓:2.5 V ~ 5.5 V 穩(wěn)壓器拓?fù)浣Y(jié)構(gòu):升壓 頻率 - 開關(guān):3MHz 板類型:完全填充 已供物品:板 已用 IC / 零件:MAX8969 |
| LM3478EVAL/NOPB | 功能描述:電源管理IC開發(fā)工具 EVAL BOARDFOR LM3478 RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
| LM3478MA/NOPB | 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
| LM3478MAX/NOPB | 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。