参数资料
型号: TPS54073PWP
厂商: TEXAS INSTRUMENTS INC
元件分类: 稳压器
英文描述: 25 A SWITCHING REGULATOR, 762 kHz SWITCHING FREQ-MAX, PDSO28
封装: GREEN, PLASTIC, HTSSOP-28
文件页数: 10/26页
文件大小: 850K
代理商: TPS54073PWP
GROUNDING AND PowerPAD LAYOUT
UNDERVOLTAGE LOCKOUT (UVLO)
SLOW-START/ENABLE (SS/ENA)
t
d +
C
(SS)
1.2 V
5 mA
(27)
t
(SS) +
C
(SS)
0.7 V
5 mA
(28)
VBIAS REGULATOR (VBIAS)
SLVS547 – FEBRUARY 2005 ............................................................................................................................................................................................ www.ti.com
The TPS54073 has two internal grounds (analog and power). Inside the TPS54073, the analog ground ties to all
of the noise-sensitive signals, whereas the power ground ties to the noisier power signals. The PowerPAD must
be tied directly to AGND. Noise injected between the two grounds can degrade the performance of the
TPS54073, particularly at higher output currents. However, ground noise on an analog ground plane can also
cause problems with some of the control and bias signals. For these reasons, separate analog and power ground
planes are recommended. These two planes must tie together directly at the IC to reduce noise between the two
grounds. The only components that must tie directly to the power ground plane are the input capacitor, the output
capacitor, the input voltage de-coupling capacitor, and the PGND pins of the TPS54073.
The TPS54073 incorporates an undervoltage-lockout circuit to keep the device disabled when the input voltage
(VIN) is insufficient. During power up, internal circuits are held inactive until VIN exceeds the nominal UVLO
threshold voltage of 2.95 V. Once the UVLO start threshold is reached, device start-up begins. The device
operates until VIN falls below the nominal UVLO stop threshold of 2.8 V. Hysteresis in the UVLO comparator,
and a 2.5-
s rising and falling edge deglitch circuit reduce the likelihood of shutting the device down due to noise
on VIN. UVLO is with respect to VIN and not PVIN, see the Application Information section.
The slow-start/enable pin provides two functions. First, the pin acts as an enable (shutdown) control by keeping
the device turned off until the voltage exceeds the start threshold voltage of approximately 1.2 V. When SS/ENA
exceeds the enable threshold, device start-up begins. The reference voltage fed to the error amplifier is linearly
ramped up from 0 V to 0.891 V in 3.35 ms. Similarly, the converter output voltage reaches regulation in
approximately 3.35 ms. Voltage hysteresis and a 2.5-
s falling edge deglitch circuit reduce the likelihood of
triggering the enable due to noise.
The second function of the SS/ENA pin provides an external means of extending the slow-start time with a
low-value capacitor connected between SS/ENA and AGND.
Adding a capacitor to the SS/ENA pin has two effects on start-up. First, a delay occurs between release of the
SS/ENA pin and start-up of the output. The delay is proportional to the slow-start capacitor value and lasts until
the SS/ENA pin reaches the enable threshold. The start-up delay is approximately:
Second, as the output becomes active, a brief ramp-up at the internal slow-start rate may be observed before the
externally set slow-start rate takes control and the output rises at a rate proportional to the slow-start capacitor.
The slow-start time set by the capacitor is approximately:
The actual slow-start time is likely to be less than the above approximation due to the brief ramp-up at the
internal rate.
The VBIAS regulator provides internal analog and digital blocks with a stable supply voltage over variations in
junction temperature and input voltage. A high-quality, low-ESR, ceramic bypass capacitor is required on the
VBIAS pin. X7R or X5R grade dielectrics are recommended because their values are more stable over
temperature. The bypass capacitor must be placed close to the VBIAS pin and returned to AGND.
External loading on VBIAS is allowed, with the caution that internal circuits require a minimum VBIAS of 2.7 V,
and external loads on VBIAS with ac or digital-switching noise may degrade performance. The VBIAS pin may be
useful as a reference voltage for external circuits. VBIAS is derived from the VIN pin; see the functional block
diagram of this data sheet.
18
Copyright 2005, Texas Instruments Incorporated
Product Folder Link(s): TPS54073
相关PDF资料
PDF描述
TPS5410QDRQ1 SWITCHING REGULATOR, PDSO8
TPS54110PWP 3.5 A SWITCHING REGULATOR, 762 kHz SWITCHING FREQ-MAX, PDSO20
TPS54110PWPG4 3.5 A SWITCHING REGULATOR, 762 kHz SWITCHING FREQ-MAX, PDSO20
TPS54140QDRCRQ1 SWITCHING REGULATOR, PDSO10
TPS54160DRCT SWITCHING REGULATOR, 2500 kHz SWITCHING FREQ-MAX, PDSO10
相关代理商/技术参数
参数描述
TPS54073PWPG4 功能描述:直流/直流开关调节器 2.2V-4.0V 14A Sync Buck 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
TPS54073PWPR 功能描述:直流/直流开关调节器 2.2V-4.0V 14A Sync Buck 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
TPS54073PWPRG4 功能描述:直流/直流开关调节器 2.2V-4.0V 14A Sync Buck 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
TPS5410 制造商:TI 制造商全称:Texas Instruments 功能描述:1-A, WIDE INPUT RANGE, STEP-DOWN SWIFT CONVERTER
TPS5410D 功能描述:直流/直流开关调节器 5.5V to 36V Input 1A Step Down Conv 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