- 您现在的位置：买卖IC网 > PDF目录297347 > SC1144ABCSW.TR SWITCHING CONTROLLER, 8500 kHz SWITCHING FREQ-MAX, PDSO24 PDF资料下载
参数资料
| 型号： | SC1144ABCSW.TR |
| 元件分类： | 稳压器 |
| 英文描述： | SWITCHING CONTROLLER, 8500 kHz SWITCHING FREQ-MAX, PDSO24 |
| 封装： | SO-24 |
| 文件页数： | 10/11页 |
| 文件大小： | 279K |
| 代理商： | SC1144ABCSW.TR |
8
2001 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC1144
PRELIMINARY
Applications Information - Functional Description (Cont.)
The effective gain of the error amplifier stays constant in
both VID ranges, keeping the loop gain constant regard-
less of output voltage range.
Fig. 3: Transient response, Top trace, Current sense
8A/div @ 30A/usec. Bottom trace, V
OUT.
Fig. 4: Top Trace, Gate drive responding to removal of
transient load. Bottom trace, Load current transient
16A/div.
Bandgap Reference/Soft Start
The precision internal bandgap reference provides a
stable, temperature compensated 2.05 V reference for
the error amplifiers non-inverting input, the DAC
REF for
the VID digital to analog converter, the under-voltage lock-
out circuitry as well as the reference for the Bias genera-
tor current sources. The error amplifiers non-inverting
input is connected to the bandgap reference through a
3 kohm resistor, which is also externally connected to a
soft-start capacitor via the B
GOUT pin. Upon application of
power, the non-inverting input of the error amplifier is
held low for a short time allowing for the decoder and
PWM controller to settle. This prevents any harmful out-
put voltage overshoots upon start up or after a converter
shutdown. The non-inverting input then ramps up accord-
ing to the RC time constant allowing gradual rise of out-
put voltage.
Isolated Feedback Ground
The feedback ground pin on the SC1144, FBG, is iso-
lated from the GND. The maximum voltage between the
two pins is set by the ESD diode forward voltage drop.
This allows the SC1144 to be configured for remote sens-
ing thus compensating for wiring and connector voltage
drops at high currents or during transients. Remote sens-
ing is typically implemented by using differential amplifi-
ers. The use of this feature on the SC1144 eliminates
the need for differential ampfication.
Over-Current Comparator
The SC1144 has an internal over-current comparator
designed to sense current in the input supply path. The
comparator inputs have a high common voltage range
thus allowing operation under all possible voltage/cur-
rent combinations. The output of the comparator pulls
the B
GOUT (soft start) pin low , thus lowering the output
voltage and causing the PWM outputs to enter minimum
duty cycle mode. When sysnchronous MOSFET drivers
are used, the Bottom FET DUTY cycle will increase.
Synchronous vs. Asynchronous Mode
The SC1144 can be configured to drive Synchronous
MOSFET drivers, such as the SC1405 for higher efficiency.
Refer to SC1405 datasheet for example designs.
Component Selection and Layout Considerations
Care must be taken in component selection and PCB
layout in high frequency power applications. Refer to
SC1144EVB user manual for more application informa-
tion on component selection and layout guidelines as well
as example Artwork and Bill of materials.
相关PDF资料 |
PDF描述 |
|---|---|
| SC141D-U | 400 V, 6 A, TRIAC, TO-220AB |
| SC141N-A | 800 V, 6 A, TRIAC, TO-220AB |
| SC141N-C | 800 V, 6 A, TRIAC, TO-220AB |
| SC141N-D1 | 800 V, 6 A, TRIAC, TO-220AB |
| SC141N-L | 800 V, 6 A, TRIAC, TO-220AB |
相关代理商/技术参数 |
参数描述 |
|---|---|
| SC1144ABCSWTRT | 制造商:Semtech Corporation 功能描述:Voltage Mode PWM Controller 24-Pin SOIC T/R |
| SC1146 | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:VRM9.0 PROGRAMMABLE, MULTI-PHASE, HIGH PERFORMANCE PWM CONTROLLER |
| SC1146CSW | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:VRM9.0 PROGRAMMABLE, MULTI-PHASE, HIGH PERFORMANCE PWM CONTROLLER |
| SC1146CSW.TR | 制造商:SEMTECH 制造商全称:Semtech Corporation 功能描述:VRM9.0 PROGRAMMABLE, MULTI-PHASE, HIGH PERFORMANCE PWM CONTROLLER |
| SC11485 | 制造商:未知厂家 制造商全称:未知厂家 功能描述:HiCOLOR-16 Color Palette |
发布紧急采购，3分钟左右您将得到回复。