- 您现在的位置：买卖IC网 > PDF目录98283 > TPS54429PWP (TEXAS INSTRUMENTS INC) 0.01 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO14 PDF资料下载
参数资料
| 型号： | TPS54429PWP |
| 厂商： | TEXAS INSTRUMENTS INC |
| 元件分类： | 稳压器 |
| 英文描述： | 0.01 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO14 |
| 封装： | GREEN, PLASTIC, HTSSOP-14 |
| 文件页数： | 21/22页 |
| 文件大小： | 651K |
| 代理商： | TPS54429PWP |
SLVSAS1
– FEBRUARY 2011
VREG5
VREG5 is an internally generated voltage source used by the TPS54429. It is derived directly from the input
voltage and is nominally regulated to 5.5 V when the input voltage is above 5.6 V. The output of the VREG5
regulator is the input to the internal UVLO function. VREG5 must be above the UVLO wake up threshold voltage
(3.8 V typical) for the TPS54429 to function. Connect a 1.0
F capacitor between pin 3 of the TPS54429 and
power ground for proper regulation of the VREG5 output. The VREG5 output voltage is available for external use
and can typically source up to 70 mA. The VREG5 output is disabled when the TPS54429 EN pin is open or
pulled low.
Output Discharge Control
TPS54429 discharges the output when EN is low, or the controller is turned off by the protection functions (OVP,
UVP, UVLO and thermal shutdown). The output is discharged by an internal 50-
MOSFET which is connected
from VO to PGND. The internal low-side MOSFET is not turned on during the output discharge operation to
avoid the possibility of causing negative voltage at the output.
Current Protection
The output over-current protection (OCP) is implemented using a cycle-by-cycle valley detect control circuit. The
switch current is monitored by measuring the low-side FET switch voltage between the SW pin and GND. This
voltage is proportional to the switch current. To improve accuracy, the voltage sensing is temperature
compensated.
During the on time of the high-side FET switch, the switch current increases at a linear rate determined by Vin,
Vout, the on-time and the output inductor value. During the on time of the low-side FET switch, this current
decreases linearly. The average value of the switch current is the load current Iout. If the measured voltage is
above the voltage proportional to the current limit, the device constantly monitors the low-side FET switch
voltage, which is proportional to the switch current, during the low-side on-time. The converter maintains the
low-side switch on until the measured voltage is below the voltage corresponding to the current limit at which
time the switching cycle is terminated and a new switching cycle begins. In subsequent switching cycles, the
on-time is set to a fixed value and the current is monitored in the same manner.
There are some important considerations for this type of over-current protection. The load current is one half of
the peak-to-peak inductor current higher than the over-current threshold. Also when the current is being limited,
the output voltage tends to fall as the demanded load current may be higher than the current available from the
converter. This may cause the output under-voltage protection circuit to be activated. When the over current
condition is removed, the output voltage will return to the regulated value. This protection is non-latching.
Over/Under Voltage Protection
The TPS54429 detects over and undervoltage conditions by monitoring the feedback voltage (VFB). This
function is enabled after approximately 1.7 times the soft-start time. When the feedback voltage becomes higher
than 120% of the target voltage, the OVP comparator output goes high and the circuit latches the high-side
MOSFET driver turns off and the low-side MOSFET turns on. When the feedback voltage becomes lower than
65% of the target voltage, the UVP comparator output goes high and an internal UVP delay counter begins. After
250
s, the device latches off both internal top and bottom MOSFET.
UVLO Protection
Undervoltage lock out protection (UVLO) monitors the voltage of the VREG5 pin. When the VREG5 voltage is lower
than UVLO threshold voltage, the TPS54429 is shut off. This is protection is non-latching.
Thermal Shutdown
Thermal protection is self-activating. If the junction temperature exceeds the threshold value (typically 165
°C),
the TPS54429 shuts off. This protection is non-latching.
8
2011, Texas Instruments Incorporated
Product Folder Link(s) :TPS54429
相关PDF资料 |
PDF描述 |
|---|---|
| TPS5450MDDAREP | 11.7 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8 |
| TPS54519RTER | 8 A SWITCHING REGULATOR, 2000 kHz SWITCHING FREQ-MAX, PQCC16 |
| TPS54612MPWPREP | 12 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO28 |
| TPS54615MPWPREP | 12 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO28 |
| TPS54622RHLT | 15 A SWITCHING REGULATOR, 1760 kHz SWITCHING FREQ-MAX, PQCC14 |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TPS54429PWPR | 功能描述:直流/直流开关调节器 7V-18Vin,4.5A Sync Step-Down DCAP2 Mode 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 |
| TPS54478 | 制造商:TI 制造商全称:Texas Instruments 功能描述:2.95-V to 6-V Input, 4-A Output, 2-MHz, Synchronous Step-Down |
| TPS54478EVM-037 | 功能描述:电源管理IC开发工具 TPS54478 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 |
| TPS54478RTER | 功能描述:直流/直流开关调节器 2.95V-6Vin,6A,Sync Step-Down 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 |
| TPS54478RTET | 功能描述:直流/直流开关调节器 2.95V-6Vin,6A,Sync Step-Down 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 |
发布紧急采购，3分钟左右您将得到回复。