参数资料
| 型号： | TPS54478RTER |
| 厂商： | Texas Instruments |
| 文件页数： | 10/38页 |
| 文件大小： | 0K |
| 描述： | IC REG BUCK SYNC ADJ 4A 16WQFN |
| 标准包装： | 3,000 |
| 系列： | SWIFT™ |
| 类型： | 降压（降压） |
| 输出类型： | 可调式 |
| 输出数： | 1 |
| 输出电压： | 0.6 V ~ 4.5 V |
| 输入电压： | 2.95 V ~ 6 V |
| PWM 型： | 电流模式 |
| 频率 - 开关： | 500kHz |
| 电流 - 输出： | 4A |
| 同步整流器： | 是 |
| 工作温度： | -40°C ~ 150°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 16-WFQFN 裸露焊盘 |
| 包装： | 带卷 (TR) |
| 供应商设备封装： | 16-WQFN 裸露焊盘（3x3） |
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页当前第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页第36页第37页第38页
SLVSAS2 – JUNE 2011
TYPICAL CHARACTERISTICS CURVES (continued)
100
95
90
EFFICIENCY vs LOAD CURRENT
100
95
90
EFFICIENCY vs LOAD CURRENT
85
80
V O = 2.5 V
V O = 1.8 V
V O = 1.2 V
V O = 1 V
85
80
V O = 3.3 V
V O = 2.5 V
V O = 1.8 V
V O = 1.2 V
V O = 1 V
75
70
65
75
70
65
60
55
Vin = 3.3 V,
DCR = 18 m W ,
Fs = 500 kHz,
Tj = 25°C
60
55
Vin = 5 V,
DCR = 18 m W ,
Fs = 500 kHz,
Tj = 25°C
50
0
0.5
1
1.5 2 2.5
3
3.5
4
50
0
0.5
1
1.5 2 2.5
3
3.5
4
I O - Output Current - A
Figure 19.
I O - Output Current - A
Figure 20.
OVERVIEW
The TPS54478 is a 6-V, 4-A, synchronous step-down (buck) converter with two integrated n-channel MOSFETs.
To improve performance during line and load transients the device implements a constant frequency, peak
current mode control which reduces output capacitance and simplifies external frequency compensation design.
The wide switching frequency of 200 kHz to 2000 kHz allows for efficiency and size optimization when selecting
the output filter components. The switching frequency is adjusted using a resistor to ground on the RT/CLK pin.
The device has an internal phase lock loop (PLL) on the RT/CLK pin that is used to synchronize the power
switch turn on to a falling edge of an external system clock.
The TPS54478 has a typical default start up voltage of 2.6 V. The EN pin has an internal pull-up current source
that can be used to adjust the input voltage under voltage lockout (UVLO) with two external resistors. In addition,
the pull up current provides a default condition when the EN pin is floating for the device to operate. The total
operating current for the TPS54478 is typically 525 μ A when not switching and under no load. When the device
is disabled, the supply current is less than 2.5 μ A.
The integrated 30 m ? MOSFETs allow for high efficiency power supply designs with continuous output currents
up to 4 amperes.
The TPS54478 reduces the external component count by integrating the boot recharge diode. The bias voltage
for the integrated high side MOSFET is supplied by a capacitor between the BOOT and PH pins. The boot
capacitor voltage is monitored by an UVLO circuit and turns off the high side MOSFET when the voltage falls
below a preset threshold. This BOOT circuit allows the TPS54478 to operate approaching 100%. The output
voltage can be stepped down to as low as the 0.600 V reference.
TPS54478 features monotonic starup under pre-bias conditions. The low side Fet turns on for a very short time
period every cycle before the output voltage reaches the pre-biased voltage. This ensures the boot cap has
enough charge to turn on the top Fet when the output voltage reaches the pre-biased voltage.
The TPS54478 has a power good comparator (PWRGD) with 2% hysteresis.
The TPS54478 minimizes excessive output overvoltage transients by taking advantage of the overvoltage power
good comparator. When the regulated output voltage is greater than 107% of the nominal voltage, the
overvoltage comparator is activated, and the high side MOSFET is turned off and masked from turning on until
the output voltage is lower than 105%.
The SS/TR (slow start/tracking) pin is used to minimize inrush currents or provide power supply sequencing
during power up. A small value capacitor should be coupled to the pin for slow start. The SS/TR pin is
discharged before the output power up to ensure a repeatable restart after an overtemperature fault, UVLO fault
or disabled condition. To optimize the output startup waveform, two levels of SS current are implemented. The
first slope has more current so that the converter can get out of the region requiring small minimum ON time.
10
Copyright ? 2011, Texas Instruments Incorporated
相关PDF资料 |
PDF描述 |
|---|---|
| TPS54550PWPG4 | IC REG BUCK SYNC ADJ 6A 16HTSSOP |
| TPS54678RTER | IC REG BUCK SYNC ADJ 6A 16WQFN |
| TPS54900PWRG4 | IC REG BUCK ADJ .1A QUAD 16TSSOP |
| TPS60110PWPG4 | IC REG BST SWITCHED CAP 20HTSSOP |
| TPS62125DSGT | IC REG BUCK SYNC ADJ 0.3A 8WSON |
相关代理商/技术参数 |
参数描述 |
|---|---|
| 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 |
| TPS54494 | 制造商:TI 制造商全称:Texas Instruments 功能描述:4A/2A Dual Channel Synchronous Step-Down Switcher with Integrated FET |
| TPS54494EVM-057 | 制造商:Texas Instruments 功能描述:Evaluation Module Access To The Features Of The TPS54494 制造商:Texas Instruments 功能描述:TPS54494EVM-057 - Boxed Product (Development Kits) 制造商:Texas Instruments 功能描述:EVAL MODULE FOR TPS54494-057 制造商:Texas Instruments 功能描述:TPS54494 Eval Mod |
| TPS54494PWP | 功能描述:直流/直流开关转换器 4A Dual Channel Sync SD Switcher RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| TPS54494PWPR | 功能描述:直流/直流开关转换器 4A Dual Channel Sync SD Switcher RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
发布紧急采购，3分钟左右您将得到回复。