- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385498 > LT1158 (Linear Technology Corporation) Half Bridge N-Channel Power MOSFET Driver(半橋,N-溝道功率MOS場效應(yīng)管驅(qū)動器) PDF資料下載
參數(shù)資料
| 型號： | LT1158 |
| 廠商： | Linear Technology Corporation |
| 英文描述： | Half Bridge N-Channel Power MOSFET Driver(半橋,N-溝道功率MOS場效應(yīng)管驅(qū)動器) |
| 中文描述： | 半橋N溝道功率MOSFET驅(qū)動器（半橋的N溝道功率馬鞍山場效應(yīng)管驅(qū)動器） |
| 文件頁數(shù)： | 11/20頁 |
| 文件大?。?/td> | 346K |
| 代理商： | LT1158 |
LT1158
11
OUTPUT CURRENT (A)
0
E
80
90
4.0
LT1158 F04
70
60
1.0
2.0
3.0
100
0.5
1.5
2.5
3.5
FIGURE 12 CIRCUIT
V
IN
= 12V
efficiency vs. output current for the Figure 12 regulator
with V
IN
= 12V.
Current Limit in Switching Regulator Applications
Current is sensed by the LT1158 by measuring the voltage
across a current shunt (low valued resistor). Normally,
this shunt is placed in the source lead of the top MOSFET
(see
Short-Circuit Protection in Bridge Applications
).
However, in step-down switching regulator applications,
the remote current sensing capability of the LT1158 allows
the actual inductor current to be sensed. This is done by
placing the shunt in the output lead of the inductor as
shown in Figure 3. Routing of the sense
+
and sense
–
PC
traces is critical to prevent stray pickup. These traces must
be routed together at minimum spacing and use a Kelvin
connection at the shunt.
When the voltage across R
SENSE
exceeds 110mV, the
LT1158 fault pin begins to conduct. By feeding the fault
signal back to a control input of the PWM, the LT1158 will
assume control of the duty cycle forming a true current
mode loop to limit the output current:
I
OUT
=
110mV
R
in current limit
SENSE
In LT3525 based circuits, connecting the fault pin to the
LT3525 soft-start pin accomplishes this function. In cir-
cuits where the LT1158 input is being driven with a ramp
or sawtooth, the fault pin is used to pull down the DC level
of the input.
The constant off-time circuits shown in Figures 10 and 12
are unique in that they also use the current sense during
normal operation. The LT1431 output reduces the normal
LT1158 110mV fault conduction threshold such that the
fault pin conducts at the required load current, thus
discharging the input ramp capacitor. In current limit the
LT1431 output turns off, allowing the fault conduction
threshold to reach its normal value.
The resistor R
GS
shown in Figure 3 is necessary to prevent
output voltage overshoot due to charge coupled into the
gate of the top MOSFET by a large start-up dv/dt on V
IN
. If
DC operation of the top MOSFET is required, R
GS
must be
330k or greater to prevent loading the charge pump.
One fundamental difference in the operation of a step-
down regulator with synchronous switching is that it never
becomes discontinuous at light loads. The inductor cur-
rent doesn’t stop ramping down when it reaches zero, but
actually reverses polarity resulting in a constant ripple
current independent of load. This does not cause any
efficiency loss as might be expected, since the negative
inductor current is returned to V
IN
when the switch turns
back on.
The LT1158 performs the synchronous MOSFET drive and
current sense functions in a step-down switching regula-
tor. A reference and PWM are required to complete the
regulator. Any voltage-mode PWM controller may be
used, but the LT3525 is particularly well suited to high
power, high efficiency applications such as the 10A circuit
shown in Figure 13. In higher current regulators a small
Schottky diode across the bottom MOSFET helps to re-
duce reverse-recovery switching losses.
The LT1158 input pin can also be driven directly with a
ramp or sawtooth. In this case, the DC level of the input
waveform relative to the 1.4V threshold sets the LT1158
duty cycle. In the 5V to 3.3V converter circuit shown in
Figure 11, an LT1431 controls the DC level of a triangle
wave generated by a CMOS 555. The Figure 10 and 12
circuits use an RC network to ramp the LT1158 input
back up to its 1.4V threshold following each switch
cycle, setting a constant off time. Figure 4 shows the
Figure 4. Typical Efficiency Curve for Step-Down
Regulator with Synchronous Switch
APPLICATIO
S I
FOR
ATIO
U
W
U
U
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LT1160 | Half-/Full-Bridge N-Channel Power MOSFET Drivers(半橋,N-溝道功率MOS場效應(yīng)管驅(qū)動器) |
| LT1161 | 1-of-8 Data Selectors/Multiplexers With 3-State Outputs 16-SOIC 0 to 70 |
| LT1161C | Quad Protected High-Side MOSFET Driver |
| LT1161CN | Quad Protected High-Side MOSFET Driver |
| LT1161CS | Quad Protected High-Side MOSFET Driver |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LT1158C | 制造商:LINER 制造商全稱:Linear Technology 功能描述:Half Bridge N-Channel Power MOSFET Driver |
| LT1158CN | 功能描述:IC MOSFET DRVR 1/2BRDG NCH 16DIP RoHS:否 類別:集成電路 (IC) >> PMIC - MOSFET，電橋驅(qū)動器 - 外部開關(guān) 系列:- 標(biāo)準(zhǔn)包裝:5 系列:- 配置:低端 輸入類型:非反相 延遲時間:600ns 電流 - 峰:12A 配置數(shù):1 輸出數(shù):1 高端電壓 - 最大（自引導(dǎo)啟動）:- 電源電壓:14.2 V ~ 15.8 V 工作溫度:-20°C ~ 60°C 安裝類型:通孔 封裝/外殼:21-SIP 模塊 供應(yīng)商設(shè)備封裝:模塊 包裝:散裝 配用:BG2A-NF-ND - KIT DEV BOARD FOR IGBT 其它名稱:835-1063 |
| LT1158CN#PBF | 功能描述:IC MOSFET DRVR 1/2BRDG NCH 16DIP RoHS:是 類別:集成電路 (IC) >> PMIC - MOSFET，電橋驅(qū)動器 - 外部開關(guān) 系列:- 標(biāo)準(zhǔn)包裝:95 系列:- 配置:高端和低端，獨(dú)立 輸入類型:非反相 延遲時間:160ns 電流 - 峰:290mA 配置數(shù):1 輸出數(shù):2 高端電壓 - 最大（自引導(dǎo)啟動）:600V 電源電壓:10 V ~ 20 V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:8-SOIC（0.154"，3.90mm 寬） 供應(yīng)商設(shè)備封裝:8-SOIC 包裝:管件 產(chǎn)品目錄頁面:1381 (CN2011-ZH PDF) |
| LT1158CS | 制造商:Linear Technology 功能描述: 制造商:LINEAR_TECH 功能描述: |
| LT1158CSW | 功能描述:IC MOSFET DRVR 1/2BRDG NCH16SOIC RoHS:否 類別:集成電路 (IC) >> PMIC - MOSFET，電橋驅(qū)動器 - 外部開關(guān) 系列:- 標(biāo)準(zhǔn)包裝:5 系列:- 配置:低端 輸入類型:非反相 延遲時間:600ns 電流 - 峰:12A 配置數(shù):1 輸出數(shù):1 高端電壓 - 最大（自引導(dǎo)啟動）:- 電源電壓:14.2 V ~ 15.8 V 工作溫度:-20°C ~ 60°C 安裝類型:通孔 封裝/外殼:21-SIP 模塊 供應(yīng)商設(shè)備封裝:模塊 包裝:散裝 配用:BG2A-NF-ND - KIT DEV BOARD FOR IGBT 其它名稱:835-1063 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。