參數(shù)資料
型號： L6599AN
廠商： STMICROELECTRONICS
元件分類： 穩(wěn)壓器
英文描述： SWITCHING CONTROLLER, DIP16
封裝： ROHS COMPLIANT, DIP-16
文件頁數(shù)： 18/36頁
文件大小： 1595K
代理商： L6599AN
L6599A
Application information
Doc ID 15308 Rev 5
25/36
Figure 28.
Current sensing techniques: a) with sense resistor, b) “l(fā)ossless”,
with capacitive shunt
The L6599A is equipped with a current sensing input (pin 6, ISEN) and a sophisticated
overcurrent management system. The ISEN pin is internally connected to the input of a first
comparator, referenced to 0.8 V, and to that of a second comparator referenced to 1.5 V. If
the voltage externally applied to the pin by either circuit in Figure 28 exceeds 0.8 V the first
comparator is tripped and this causes an internal switch to be turned on and discharge the
soft-start capacitor CSS (see Section 7.3: Soft-start). This will quickly increase the oscillator
frequency and thereby limit energy transfer. The discharge will go on until the voltage on the
ISEN pin has dropped by 50 mV; this, with an averaging time in the range of 10/fmin, ensures
an effective frequency rise. Under output short circuit, this operation results in a nearly
constant peak primary current.
It is normal that the voltage on the ISEN pin may overshoot above 0.8 V; however, if the
voltage on the ISEN pin reaches 1.5 V, the second comparator will be triggered, the L6599A
will shutdown and latch off with both the gate-drive outputs and the PFC_STOP pin low,
hence turning off the entire unit. The supply voltage of the IC must be pulled below the
UVLO threshold and then again above the start-up level in order to restart. Such an event
may occur if the soft-start capacitor CSS is too large, so that its discharge is not fast enough
or in case of transformer’s magnetizing inductance saturation or a shorted secondary
rectifier.
In the circuit shown in Figure 28a, where a sense resistor Rs in series to the source of the
low-side MOSFET is used, note the particular connection of the resonant capacitor. In this
way the voltage across Rs is related to the current flowing through the high-side MOSFET
and is positive most of the switching period, except for the time needed for the resonant
current to reverse after the low-side MOSFET has been switched off. Assuming that the time
constant of the RC filter is at least ten times the minimum switching frequency fmin, the
approximate value of Rs can be found using the empirical equation:
Equation 6
where ICrpkx is the maximum desired peak current flowing through the resonant capacitor
and the primary winding of the transformer, which is related to the maximum load and the
minimum input voltage.
Crpkx
pkx
I
4
I
8
.
0
5
I
Vs
Rs
≈
≈
=
相關PDF資料
PDF描述
L6599ATDTR SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16
L6599D 0.8 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16
L6599N 0.8 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDIP16
L6599TR 0.8 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16
L6610D 6-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO24
相關代理商/技術參數(shù)
參數(shù)描述
L6599ATD 功能描述:電壓模式 PWM 控制器 Sgl Output 13.3 V 200 KHz SOIC-16 Nrw RoHS:否 制造商:Texas Instruments 輸出端數(shù)量:1 拓撲結(jié)構(gòu):Buck 輸出電壓:34 V 輸出電流: 開關頻率: 工作電源電壓:4.5 V to 5.5 V 電源電流:600 uA 最大工作溫度:+ 125 C 最小工作溫度:- 40 C 封裝 / 箱體:WSON-8 封裝:Reel
L6599ATDTR 功能描述:開關變換器、穩(wěn)壓器與控制器 IMPROVED High-Volt RESONANT CONTROLLER RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel
L6599ATN 制造商:STMicroelectronics 功能描述:
L6599D 功能描述:軟開關 PWM 控制器 Hi Vltg resonant Controller RoHS:否 制造商:Fairchild Semiconductor 輸出端數(shù)量: 輸出電流: 開關頻率: 工作電源電壓:30 V 電源電流: 最大工作溫度:+ 105 C 最小工作溫度:- 40 C 安裝風格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel
L6599DTR 功能描述:軟開關 PWM 控制器 Hi Vltg resonant Controller RoHS:否 制造商:Fairchild Semiconductor 輸出端數(shù)量: 輸出電流: 開關頻率: 工作電源電壓:30 V 電源電流: 最大工作溫度:+ 105 C 最小工作溫度:- 40 C 安裝風格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel
發(fā)布緊急采購，3分鐘左右您將得到回復。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*