- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄383234 > L5991 (意法半導(dǎo)體) PRIMARY CONTROLLER WITH STANDBY PDF資料下載
參數(shù)資料
| 型號： | L5991 |
| 廠商： | 意法半導(dǎo)體 |
| 英文描述： | PRIMARY CONTROLLER WITH STANDBY |
| 中文描述： | 主控制器具有待機 |
| 文件頁數(shù)： | 11/19頁 |
| 文件大小： | 192K |
| 代理商： | L5991 |
Since the system tries restarting each hiccup cy-
cle, there is not any latchoffrisk.
”Hiccup” keeps the system in control in case of
short circuits but does not eliminate power com-
ponents overstress during pulse-by-pulse limita-
tion (from A to C). Other external protection cir-
cuits are needed if a better control of overloads is
required.
Pin 8.
VCC (Controller Supply). This pin supplies
the signal part of the IC. The device is enabled as
VCC voltage exceeds the start threshold and
works as long as the voltage is above the UVLO
threshold. Otherwise the device is shut down and
the
current
consumption
(<150
μ
A). This is particularly useful for reducing
the consumptionof the start-upcircuit (in the sim-
plest case, just one resistor), which is one of the
most significant contributions to power losses in
standby.
An internal Zener limits the voltage on VCC to
25V. The IC current consumption increases con-
siderably if thislimit is exceeded.
A smallfilm capacitor between this pin and SGND
(pin 12), placed as close as possible to the IC, is
recommendedto filterhigh frequencynoise.
is
extremely
low
Pin 9.
VC (Supply of thePower Stage). It supplies
the driver of the external switch and therefore ab-
sorbs a pulsedcurrent. Thus it is recommendedto
place a buffer capacitor (towards PGND, pin 11,
as close as possible to the IC) able to sustain
these current pulses and in order to avoid them
inducingdisturbances.
This pin can be connected to the buffer capacitor
directly or through a resistor, as shown in fig. 26,
to control separately the turn-on and turn-off
speed of the external switch, typically a Power-
MOS.At turn-on the gate resistanceis R
g
+ R
g’
, at
turn-offis R
g
only.
Pin 10.
OUT (Driver Output). This pin is the out-
put of the driver stage of the external power
switch. Usually, this will be a PowerMOS, al-
though the driver is powerful enough to drive
BJT’s (1.6A source,2A sink,peak).
The driver is made up of a totempole with a high-
side NPN Darlington and a low-sideVDMOS, thus
there is no need of an external diode clamp to
prevent voltage from going below ground. An in-
ternal clamp limits the voltage delivered to the
gate at 13V. Thus it is possible to supply the
driver (Pin 9) with higher voltages without any risk
of damagefor thegate oxide of the externalMOS.
The clamp does not cause any additional in-
crease of power dissipation inside the chip since
the current peak of the gate charge occurs when
the gate voltage is few volts and the clamp is not
active. Besides, no current flows when the gate
voltageis 13V,steady state.
Under UVLO conditions an internal circuit (shown
7V
T
hic
time
SHORT
I
OUT
I
SEN
FAULT
SS
5V
0.5V
D98IN986
Figure 25. Hiccup modeoperation.
OUT
Rg
DRIVE
&
CONTROL
13V
V
C
9
V
CC
Rg’
PGND
Rg(ON)=Rg+Rg’
Rg(OFF)=Rg
D97IN726
L5991
10
11
8
Figure26. Turn-on and turn-offspeedsadjust-
ment.
L5991 - L5991A
11/23
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| L5991A | PRIMARY CONTROLLER WITH STANDBY |
| L5991AD | PRIMARY CONTROLLER WITH STANDBY |
| L5991D | PRIMARY CONTROLLER WITH STANDBY |
| L5993 | CONSTANT POWER CONTROLLER |
| L5993D | CONSTANT POWER CONTROLLER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| L5991_01 | 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:PRIMARY CONTROLLER WITH STANDBY |
| L5991A | 功能描述:電流型 PWM 控制器 Prog Current Mode RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14 |
| L5991AD | 功能描述:開關(guān)變換器、穩(wěn)壓器與控制器 Prog Current Mode 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(guān)頻率:1 MHz 工作溫度范圍: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel |
| L5991AD13TR | 功能描述:電流型 PWM 控制器 Prog Current Mode RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14 |
| L5991D | 功能描述:電流型 PWM 控制器 Prog Current Mode RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。