- 您現(xiàn)在的位置：買賣IC網 > PDF目錄98283 > TPS54418RTER (TEXAS INSTRUMENTS INC) 6.4 A SWITCHING REGULATOR, 2000 kHz SWITCHING FREQ-MAX, PQCC16 PDF資料下載
參數資料
| 型號： | TPS54418RTER |
| 廠商： | TEXAS INSTRUMENTS INC |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | 6.4 A SWITCHING REGULATOR, 2000 kHz SWITCHING FREQ-MAX, PQCC16 |
| 封裝： | 3 X 3 MM, GREEN, PLASTIC, WQFN-16 |
| 文件頁數： | 3/35頁 |
| 文件大?。?/td> | 1356K |
| 代理商： | TPS54418RTER |
第1頁第2頁當前第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁
O
0.8 V
R2 = R1
V
0 .8 V
÷
-
è
www.ti.com
SLVS946A – MAY 2009 – REVISED MAY 2010
DETAILED DESCRIPTION
FIXED FREQUENCY PWM CONTROL
The TPS54418 uses an adjustable fixed frequency, peak current mode control. The output voltage is compared
through external resistors on the VSENSE pin to an internal voltage reference by an error amplifier which drives
the COMP pin. An internal oscillator initiates the turn on of the high side power switch. The error amplifier output
is compared to the high side power switch current. When the power switch current reaches the COMP voltage
level the high side power switch is turned off and the low side power switch is turned on. The COMP pin voltage
increases and decreases as the output current increases and decreases. The device implements a current limit
by clamping the COMP pin voltage to a maximum level and also implements a minimum clamp for improved
transient response performance.
SLOPE COMPENSATION AND OUTPUT CURRENT
The TPS54418 adds a compensating ramp to the switch current signal. This slope compensation prevents
sub-harmonic oscillations as duty cycle increases. The available peak inductor current remains constant over the
full duty cycle range.
BOOTSTRAP VOLTAGE (BOOT) AND LOW DROPOUT OPERATION
The TPS54418 has an integrated boot regulator and requires a small ceramic capacitor between the BOOT and
PH pin to provide the gate drive voltage for the high side MOSFET. The value of the ceramic capacitor should be
0.1 mF. A ceramic capacitor with an X7R or X5R grade dielectric with a voltage rating of 10 V or higher is
recommended because of the stable characteristics over temperature and voltage.
To improve drop out, the TPS54418 is designed to operate at 100% duty cycle as long as the BOOT to PH pin
voltage is greater than 2.5 V. The high side MOSFET is turned off using an UVLO circuit, allowing for the low
side MOSFET to conduct when the voltage from BOOT to PH drops below 2.5 V. Since the supply current
sourced from the BOOT pin is very low, the high side MOSFET can remain on for more switching cycles than are
required to refresh the capacitor, thus the effective duty cycle of the switching regulator is very high.
ERROR AMPLIFIER
The TPS54418 has a transconductance amplifier. The error amplifier compares the VSENSE voltage to the lower
of the SS pin voltage or the internal 0.8 V voltage reference. The transconductance of the error amplifier is 225
mA/V during normal operation. When the voltage of VSENSE pin is below 0.8 V and the device is regulating
using the SS voltage, the gm is 70 mA/V. The frequency compensation components are placed between the
COMP pin and ground.
VOLTAGE REFERENCE
The voltage reference system produces a precise ±1% voltage reference over temperature by scaling the output
of a temperature stable bandgap circuit. The bandgap and scaling circuits produce 0.8 V at the non-inverting
input of the error amplifier.
ADJUSTING THE OUTPUT VOLTAGE
The output voltage is set with a resistor divider from the output node to the VSENSE pin. It is recommended to
use divider resistors with 1% tolerance or better. Start with a 100 k
for the R1 resistor and use the Equation 1
to calculate R2. To improve efficiency at very light loads consider using larger value resistors. If the values are
too high the regulator is more susceptible to noise and voltage errors from the VSENSE input current are
noticeable.
(1)
Copyright 2009–2010, Texas Instruments Incorporated
11
Product Folder Link(s): TPS54418
相關PDF資料 |
PDF描述 |
|---|---|
| TPS54426PWP | 7.5 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO14 |
| TPS54429PWP | 0.01 A SWITCHING REGULATOR, 700 kHz SWITCHING FREQ-MAX, PDSO14 |
| 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 |
相關代理商/技術參數 |
參數描述 |
|---|---|
| TPS54418RTERG4 | 制造商:Texas Instruments 功能描述: |
| TPS54418RTET | 功能描述:直流/直流開關調節(jié)器 2.95-6Vin 4A 2MHz Synch St Down RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關頻率:1.5 MHz 輸出電壓:0.5 V to 0.86 V 輸出電流:4 A 輸出端數量: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
| TPS54424RNVT | 功能描述:4.5V TO 17V INPUT, CURRENT MODE, 制造商:texas instruments 系列:SWIFT?? 包裝:剪切帶（CT） 零件狀態(tài):在售 功能:降壓 輸出配置:正 拓撲:降壓 輸出類型:可調式 輸出數:1 電壓 - 輸入（最小值）:4.5V 電壓 - 輸入（最大值）:17V 電壓 - 輸出（最小值/固定）:0.6V 電壓 - 輸出（最大值）:12V 電流 - 輸出:4A 頻率 - 開關:200kHz ~ 1.6MHz 同步整流器:是 工作溫度:-40°C ~ 150°C（TJ） 安裝類型:表面貼裝 封裝/外殼:18-VFQFN 供應商器件封裝:18-VQFN-HR（3.5x3.5） 標準包裝:1 |
| TPS54425 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:4-A OUTPUT SINGLE SYNCHRONOUS STEP DOWN SWITCHER WITH INTEGRATED FET ( SWIFT?) |
| TPS54425_10 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:4-A OUTPUT SINGLE SYNCHRONOUS STEP DOWN SWITCHER WITH INTEGRATED FET ( SWIFT?) |
發(fā)布緊急采購，3分鐘左右您將得到回復。