- 您现在的位置：买卖IC网 > PDF目录69510 > TPS53126PWR (TEXAS INSTRUMENTS INC) 0.17 A DUAL SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO24 PDF资料下载
参数资料
| 型号： | TPS53126PWR |
| 厂商： | TEXAS INSTRUMENTS INC |
| 元件分类： | 稳压器 |
| 英文描述： | 0.17 A DUAL SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO24 |
| 封装： | PLASTIC, TSSOP-24 |
| 文件页数： | 30/30页 |
| 文件大小： | 899K |
| 代理商： | TPS53126PWR |
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页当前第30页
DETAILED DESCRIPTION
PWM OPERATION
DRIVERS
PWM FREQUENCY AND ADAPTIVE ON-TIME CONTROL
5 VOLT REGULATOR
SOFT START
PRE-BIAS SUPPORT
www.ti.com........................................................................................................................................................................................................ SLUS909 – MAY 2009
The main control loop of the TPS53126 is an adaptive on-time pulse width modulation (PWM) controller that
supports a proprietary D-CAP2 mode control. D-CAP2 Mode control combines constant on-time control with an
internal compensation circuit for pseudo-fixed frequency and low external component count configuration with
both low ESR and ceramic output capacitors. It is stable even with virtually no ripple at the output.
At the beginning of each cycle, the high-side MOSFET is turned on. This MOSFET is turned off after internal one
shot timer expires. This one shot timer is set by the converter input voltage ,VIN, and the output voltage ,VO, to
maintain a pseudo-fixed frequency over the input voltage range, hence it is called adaptive on-time control. The
one-shot timer is reset and the high-side MOSFET is turned on again when the feedback voltage falls below the
reference voltage. An internal ramp is added to the reference voltage to simulate output ripple, eliminating the
need for ESR induced output ripple from D-CAP mode control.
Each SMPS of the TPS53126 contains 2 high-current resistive MOSFET drivers. The Low-side driver is a ground
referenced, VREG5 powered driver designed to drive the gate of a high-current, low RDS(on) N-channel MOSFET
whose source is connected to PGND. The High-side Driver is a floating SW referenced VBST powered driver
designed to drive the gate of a high-current, low RDS(on) N-channel MOSFET. To maintain the BST voltage during
the high-side driver ON time, a capacitor is placed from SW to VBST. Each driver draws average current equal to
Gate Charge (Qg AT Vgs = 5V) times Switching Frequency (fsw).
To prevent cross-conduction, there is a narrow dead-time when both high-side and low-side drivers are OFF
between each driver transition. During this time the inductor current is carried by one of the MOSFETs body
diodes.
The TPS53126 uses an adaptive on-time control scheme and does not have a dedicated on board oscillator. The
TPS53126 runs with pseudo-constant frequency by using the input voltage and output voltage to set the on-time
one-shot timer. The on-time is inversely proportional to the input voltage and proportional to the output voltage,
therefore, when the duty ratio is VOUT/VIN, the frequency is constant.
The TPS53126 has an internal 5V Low-Dropout (LDO) Regulator to provide a regulated voltage for all four
drivers and the ICs internal logic. A capacitor from VREG5 to GND is required to stabilize the internal regular. An
internal 10
resistor from VREG5 filters the regulator output to the IC’s analog and logic input voltage, V5FILT.
An additional capacitor is required from V5FILT to GND to filter switching noise from VREG5.
The TPS53126 has an internal, 1.2ms, voltage servo soft-start for each channel. When the ENx pin becomes
high, an internal DAC begins ramping up the reference voltage to the PWM comparator. Smooth control of the
output voltage is maintained during start up. As the TPS53126 shares one DAC with both channels, if ENx pin is
set to high while another channel is starting up, soft start is postponed until another channel soft start has
completed. If both of EN1 and EN2 are set high at a same time, both channels start up at same time.
The TPS53126 supports pre-bias start-up without sinking current from the output capacitor. When enabled, the
low-side driver is held off until the soft-start commands a voltage higher than the pre-bias level (internal soft-start
becomes greater than feedback voltage [VFB]), then the TPS53126 slowly activates synchronous rectification by
limiting the first DRVL pulses with a narrow on-time. This limited on-time is then incremented on a cycle-by-cycle
basis until it coincides with the full 1-D off-time. This scheme prevents the initial sinking of current from the
pre-bias output, and ensure that the output voltage (VOUT) starts and ramps up smoothly into regulation and the
control loop is given time to transition from pre-biased start-up to normal mode operation.
Copyright 2009, Texas Instruments Incorporated
9
Product Folder Link(s): TPS53126
相关PDF资料 |
PDF描述 |
|---|---|
| TPS53126RGET | 0.17 A DUAL SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PQCC24 |
| TPS53126PW | 0.17 A DUAL SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO24 |
| TPS53129PWR | DUAL SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PDSO24 |
| TPS53129RGET | DUAL SWITCHING CONTROLLER, 700 kHz SWITCHING FREQ-MAX, PQCC24 |
| TPS53315RGFR | SWITCHING REGULATOR, 1070 kHz SWITCHING FREQ-MAX, PQCC40 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TPS53126RGER | 功能描述:DC/DC 开关控制器 Dual Sync. Step Down Controller RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| TPS53126RGET | 功能描述:DC/DC 开关控制器 Dual Sync. Step Down Controller RoHS:否 制造商:Texas Instruments 输入电压:6 V to 100 V 开关频率: 输出电压:1.215 V to 80 V 输出电流:3.5 A 输出端数量:1 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:CPAK |
| TPS53127 | 制造商:TI 制造商全称:Texas Instruments 功能描述:DUAL SYNCHRONOUS STEP-DOWN CONTROLLER FOR LOW VOLTAGE POWER RAILS |
| TPS53127_1 | 制造商:TI 制造商全称:Texas Instruments 功能描述:DUAL SYNCHRONOUS STEP-DOWN CONTROLLER FOR LOW VOLTAGE POWER RAILS |
| TPS53127EVM-614 | 功能描述:电源管理IC开发工具 TPS53127 Eval Mod RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
发布紧急采购，3分钟左右您将得到回复。