- 您现在的位置：买卖IC网 > PDF目录69514 > TPS61029DRCR (TEXAS INSTRUMENTS INC) 2.1 A SWITCHING REGULATOR, 720 kHz SWITCHING FREQ-MAX, PDSO10 PDF资料下载
参数资料
| 型号： | TPS61029DRCR |
| 厂商： | TEXAS INSTRUMENTS INC |
| 元件分类： | 稳压器 |
| 英文描述： | 2.1 A SWITCHING REGULATOR, 720 kHz SWITCHING FREQ-MAX, PDSO10 |
| 封装： | 3 X 3 MM, GREEN, PLASTIC, SON-10 |
| 文件页数： | 4/29页 |
| 文件大小： | 746K |
| 代理商： | TPS61029DRCR |
第1页第2页第3页当前第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
www.ti.com
DETAILED DESCRIPTION
CONTROLLER CIRCUIT
Synchronous Rectifier
Down Regulation
Device Enable
SLVS451D – SEPTEMBER 2003 – REVISED FEBRUARY 2006
The controller circuit of the device is based on a fixed frequency multiple feedforward controller topology. Input
voltage, output voltage, and voltage drop on the NMOS switch are monitored and forwarded to the regulator. So
changes in the operating conditions of the converter directly affect the duty cycle and must not take the indirect
and slow way through the control loop and the error amplifier. The control loop, determined by the error amplifier,
only has to handle small signal errors. The input for it is the feedback voltage on the FB pin or, at fixed output
voltage versions, the voltage on the internal resistor divider. It is compared with the internal reference voltage to
generate an accurate and stable output voltage.
The peak current of the NMOS switch is also sensed to limit the maximum current flowing through the switch and
the inductor. The typical peak current limit is set to 1500 mA. An internal temperature sensor prevents the device
from getting overheated in case of excessive power dissipation.
The device integrates an N-channel and a P-channel MOSFET transistor to realize a synchronous rectifier.
Because the commonly used discrete Schottky rectifier is replaced with a low RDS(ON) PMOS switch, the power
conversion efficiency reaches 96%. To avoid ground shift due to the high currents in the NMOS switch, two
separate ground pins are used. The reference for all control functions is the GND pin. The source of the NMOS
switch is connected to PGND. Both grounds must be connected on the PCB at only one point close to the GND
pin. A special circuit is applied to disconnect the load from the input during shutdown of the converter. In
conventional synchronous rectifier circuits, the backgate diode of the high-side PMOS is forward biased in
shutdown and allows current flowing from the battery to the output. This device however uses a special circuit
which takes the cathode of the backgate diode of the high-side PMOS and disconnects it from the source when
the regulator is not enabled (EN = low).
The benefit of this feature for the system design engineer is that the battery is not depleted during shutdown of
the converter. No additional components have to be added to the design to make sure that the battery is
disconnected from the output of the converter.
In general, a boost converter only regulates output voltages which are higher than the input voltage. This device
operates differently. For example, it is able to regulate 3.0 V at the output with two fresh alkaline cells at the input
having a total cell voltage of 3.2 V. Another example is powering white LEDs with a forward voltage of 3.6 V from
a fully charged Li-Ion cell with an output voltage of 4.2 V. To control these applications properly, a down
conversion mode is implemented.
If the input voltage reaches or exceeds the output voltage, the converter changes to the conversion mode. In this
mode, the control circuit changes the behavior of the rectifying PMOS. It sets the voltage drop across the PMOS
as high as needed to regulate the output voltage. This means the power losses in the converter increase. This
has to be taken into account for thermal consideration. The down conversion mode is automatically turned off as
soon as the input voltage falls about 50 mV below the output voltage. For proper operation in down conversion
mode the output voltage should not be programmed below 50% of the maximum input voltage which can be
applied.
The device is put into operation when EN is set high. It is put into a shutdown mode when EN is set to GND. In
shutdown mode, the regulator stops switching, all internal control circuitry including the low-battery comparator is
switched off, and the load is isolated from the input (as described in the Synchronous Rectifier Section). This
also means that the output voltage can drop below the input voltage during shutdown. During start-up of the
converter, the duty cycle and the peak current are limited in order to avoid high peak currents drawn from the
battery.
12
Copyright 2003–2006, Texas Instruments Incorporated
相关PDF资料 |
PDF描述 |
|---|---|
| TPS61027DRC | 1.8 A SWITCHING REGULATOR, 720 kHz SWITCHING FREQ-MAX, PDSO10 |
| TPS61029DRC | 2.1 A SWITCHING REGULATOR, 720 kHz SWITCHING FREQ-MAX, PDSO10 |
| TPS61027DRCT | 1.8 A SWITCHING REGULATOR, 720 kHz SWITCHING FREQ-MAX, PDSO10 |
| TPS61020DRCT | 1.8 A SWITCHING REGULATOR, 720 kHz SWITCHING FREQ-MAX, PDSO10 |
| TPS61027QDRCRQ1 | BATTERY CHARGE CONTROLLER, PDSO10 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TPS61029DRCRG4 | 功能描述:直流/直流开关调节器 Adj 1.8-A Switch Boost Converter RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| TPS61029DRCT | 功能描述:直流/直流开关调节器 Adj 1.8-A Switch Boost Converter RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| TPS61029DRCTG4 | 功能描述:直流/直流开关调节器 Adj 1.8-A Switch Boost Converter RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| TPS61029DRCTRG4 | 制造商:Texas Instruments 功能描述:STEP UP CONVERTER ADJ 1.8A SOIC10 |
| TPS61029-Q1 | 制造商:TI 制造商全称:Texas Instruments 功能描述:96% EFFICIENT SYNCHRONOUS BOOST CONVERTERS |
发布紧急采购，3分钟左右您将得到回复。