- 您现在的位置：买卖IC网 > PDF目录69283 > PWL6030B1AACMR (TEXAS INSTRUMENTS INC) 1-CHANNEL POWER SUPPLY MANAGEMENT CKT, PBGA187 PDF资料下载
参数资料
| 型号： | PWL6030B1AACMR |
| 厂商： | TEXAS INSTRUMENTS INC |
| 元件分类： | 电源管理 |
| 英文描述： | 1-CHANNEL POWER SUPPLY MANAGEMENT CKT, PBGA187 |
| 封装： | 7 X 7 MM, 0.40 MM PITCH, GREEN, FCBGA-187 |
| 文件页数： | 36/97页 |
| 文件大小： | 937K |
| 代理商： | PWL6030B1AACMR |
第1页第2页第3页第4页第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页当前第36页第37页第38页第39页第40页第41页第42页第43页第44页第45页第46页第47页第48页第49页第50页第51页第52页第53页第54页第55页第56页第57页第58页第59页第60页第61页第62页第63页第64页第65页第66页第67页第68页第69页第70页第71页第72页第73页第74页第75页第76页第77页第78页第79页第80页第81页第82页第83页第84页第85页第86页第87页第88页第89页第90页第91页第92页第93页第94页第95页第96页第97页
SWCS045B
– SEPTEMBER 2010 – REVISED JUNE 2011
Soft Start
Each SMPS has an internal soft-start circuit that limits the inrush current during start up. This limits input voltage
drops when a battery or a high-impedance power source is connected to the input of the converter. The soft-start
system progressively increases the ON-time from a minimum pulse-width of 30 ns as a function of the output
voltage. This mode of operation continues for 140
s after enable. If the output voltage does not reach its
targeted value by this time, such as in the case of heavy load, the soft-start transitions to a second mode of
operation. The converter then operates in a current-limit mode, specifically the P-MOS current limit is set to half
the nominal limit and the N-channel MOSET remains on until the inductor current is reset. After an additional 100
s, the device ramps up to full current limit operation, providing the output voltage rises above approximately 0.7
V. Therefore, the start-up time depends primarily on the output capacitor and load current.
Inductor Selection
All step-down converters are designed to operate with an effective inductance value from 0.30 to 1.30
H and
with output capacitors from 4 to 15
F. The output capacitor maximum value is normally used during the start-up
phase, when the capacitor is still unbiased. The internal compensation is optimized to operate with an output
filter of L = 1
H and CO = 10 F. Larger or smaller inductor values can be used to optimize the performance of
the device for specific operation conditions.
The inductor value affects the following:
Peak-to-peak ripple current
PWM-to-PFM transition point
Output voltage ripple
Efficiency
The selected inductor must be rated for its DC resistance and saturation current. The ripple current of the
inductor decreases with higher inductance and increases with higher VI or VO.
In high-frequency converter applications, the efficiency is mostly affected by the inductor AC resistance (quality
factor) and, to a smaller extent, by the inductor DCR value. To achieve high-efficiency operation, special care
must be taken to select inductors featuring a quality factor above 20 at the switching frequency. Increasing the
inductor value produces lower RMS currents, but degrades the transient response. For a given physical inductor
size, increased inductance usually results in an inductor with lower saturation current.
The total losses of the coil consist of both the losses in the DC resistance and the following frequency-dependent
components:
The losses in the core material (magnetic hysteresis loss, especially at high switching frequencies)
Additional losses in the conductor from the skin effect (current displacement at high frequencies)
Magnetic field losses of the neighboring windings (proximity effect)
Radiation losses
Output Capacitor Selection
SMPS advanced fast-response voltage mode control allows the use of tiny ceramic capacitors. Ceramic
capacitors, with low ESR values, provide the lowest output voltage ripple. The output capacitor requires either an
X7R or an X5R dielectric.
NOTE
Aside from their wide variation in capacitance overtemperature, Y5V and Z5U dielectric
capacitors become resistive at high frequencies.
At nominal load current, the device operates in PWM mode and the overall output voltage ripple is the sum of the
voltage step caused by the output capacitor ESL and the ripple current flowing through the output capacitor
reactance.
At light loads, the device operates in power-save mode and the output voltage ripple is independent of the output
capacitor value. The output voltage ripple is set by the internal comparator thresholds and propagation delays.
Copyright
2010–2011, Texas Instruments Incorporated
41
相关PDF资料 |
PDF描述 |
|---|---|
| PWL6030B1AECMR | 1-CHANNEL POWER SUPPLY MANAGEMENT CKT, PBGA187 |
| PWL6030B1AECMRR | 1-CHANNEL POWER SUPPLY MANAGEMENT CKT, PBGA187 |
| PWL6030B1A4CMRR | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PBGA187 |
| PWL6030B1AFCMRR | 1-CHANNEL POWER SUPPLY MANAGEMENT CKT, PBGA187 |
| PWL6030B1A0CMRR | 1-CHANNEL POWER SUPPLY MANAGEMENT CKT, PBGA187 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| PWLA211 | 制造商:Honeywell Sensing and Control 功能描述: |
| PWLA8390MTBLK20 | 制造商:Intel 功能描述:Server Adapter |
| PWLA8390MTG1P20 | 制造商:Intel 功能描述:INTEL PRO/1000 MT DESKTOP ADAPTER OEM VERSION - Bulk |
| PWLA8391GT | 制造商:Intel 功能描述:GT Desktop Adapter 制造商:Intel 功能描述:Bulk |
| PWLA8391GT 864968 | 制造商:Intel 功能描述:INTEL PRO/1000 GT DESKTOP ADAPTER - Bulk |
发布紧急采购，3分钟左右您将得到回复。