參數(shù)資料
型號: L5991A
廠商: 意法半導體
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): 13/19頁
文件大小: 192K
代理商: L5991A
connecting DC-LIM to VREF (half duty cycle op-
tion), Dx will be set approximatelyat:
D
x
R
T
2
R
T
+
260
(
11
)
and the output switching frequency will be halved
with respect to the oscillator one because an in-
ternal T flip-flop (see block diagram) is activated.
Fig. 30 showsthe operation.
The half duty cycle option speeds up the dis-
charge of the timing capacitor C
T
(in order to get
duty cycles as close to 50% as possible) so the
oscillatorfrequency- with thesame timing compo-
nentswill be slightly higher.
Pin 16
. S-BY(StandbyFunction).The resistor R
B
,
along with R
A
, sets the operating frequencyof the
oscillatorin normal operation(f
osc
). In fact,as long
as the STANDBY signal is high, the pin is inter-
nally connected to the referencevoltage VREF by
a N-channel FET (see fig. 31), so the timing ca-
pacitor C
T
is charged through R
A
and R
B
. When
the STANDBY signal goeslow theN-channelFET
is turned off and the pin becomes floating. R
B
is
+
-
C
D97IN502
DIS
D
R
Q
DISABLE
UVLO
2.5V
14
DISABLE
SIGNAL
Figure 29. Disable (Latched).
V15=GND
V5=V13=GND
V15=VREF
V5=V13=GND
t
d
t
d
tc
tc
V2
V10
V2
V10
D
X
=
tc
tc+ td
D
X
=
tc
2 ·tc+ td
D97IN498
Figure 30. Half duty cycle option.
-
+
-
+
2.5
2.5/4
R
STANDBY
10V
LEVEL SHIFT
COMP
FB
VREF
ST-BY
4
16
6
RCT
C
T
R
A
R
B
2
5
LOW
HIGH
STANDBY
D97IN752B
V
T1
2.5V
V
T2
4V
V
COMP
-
+
ISEN
13
R
DRIVER
OUT
STANDBY BLOCK
2R
Figure 31. Standbyfunction internal schematicand operation.
L5991 - L5991A
13/23
相關PDF資料
PDF描述
L5991AD PRIMARY CONTROLLER WITH STANDBY
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L5993 CONSTANT POWER CONTROLLER
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L5995 Accurate 4 Bit Programmable Power Supply Controller for Mobile CPU(用于移動CPU的精確4位可編程電源控制器)
相關代理商/技術參數(shù)
參數(shù)描述
L5991AD 功能描述:開關變換器、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
L5991AD13TR 功能描述:電流型 PWM 控制器 Prog Current Mode RoHS:否 制造商:Texas Instruments 開關頻率: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 安裝風格:SMD/SMT 封裝 / 箱體:TSSOP-14
L5991D013TR 功能描述:電流型 PWM 控制器 Prog Current Mode RoHS:否 制造商:Texas Instruments 開關頻率: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 安裝風格:SMD/SMT 封裝 / 箱體:TSSOP-14
L5993 功能描述:開關變換器、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