- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄382679 > TPS54672PWPR Analog IC PDF資料下載
參數(shù)資料
| 型號(hào)： | TPS54672PWPR |
| 英文描述： | Analog IC |
| 中文描述： | 模擬IC |
| 文件頁數(shù)： | 8/16頁 |
| 文件大?。?/td> | 260K |
| 代理商： | TPS54672PWPR |
TPS54611, TPS54612, TPS54613
TPS54614, TPS54615, TPS54616
SLVS400A
–
AUGUST 2001
–
REVISED JANUARY 2002
8
www.ti.com
detailed description (continued)
oscillator and PWM ramp
The oscillator frequency can be set to internally fixed values of 350 kHz or 550 kHz using the FSEL pin as a
static digital input. If a different frequency of operation is required for the application, the oscillator frequency
can be externally adjusted from 280 kHz to 700 kHz by connecting a resistor from the RT pin to AGND and
floating the FSEL pin. The switching frequency is approximated by the following equation, where R is the
resistance from RT to AGND:
Switching Frequency
100 k
R
500 [kHz]
The following table summarizes the frequency selection configurations:
SWITCHING FREQUENCY
SYNC PIN
RT PIN
350 kHz, internally set
Float or AGND
≥
2.5 V
Float
Float
550 kHz, internally set
Float
Externally set 280 kHz to 700 kHz
R = 180 k to 68 k
error amplifier
The high performance, wide bandwidth, voltage error amplifier is gain-limited to provide internal compensation
of the control loop. The user is given limited flexibility in choosing output L and C filter components. Inductance
values of 4.7
μ
H to 10
μ
H are typical and available from several vendors. The resulting designs exhibit good
noise and ripple characteristics, but with exceptional transient response. Transient recovery times are typically
in the range of 10
μ
s to 20
μ
s.
PWM control
Signals from the error amplifier output, oscillator, and current limit circuit are processed by the PWM control
logic. Referring to the internal block diagram, the control logic includes the PWM comparator, OR gate, PWM
latch, and portions of the adaptive dead-time and control logic block. During steady-state operation below the
current limit threshold, the PWM comparator output and oscillator pulse train alternately set and reset the PWM
latch. Once the PWM latch is set, the low-side FET remains on for a minimum duration set by the oscillator pulse
width. During this period, the PWM ramp discharges rapidly to its valley voltage. When the ramp begins to
charge back up, the low-side FET turns off and high-side FET turns on. As the PWM ramp voltage exceeds the
error amplifier output voltage, the PWM comparator resets the latch, thus turning off the high-side FET and
turning on the low-side FET. The low-side FET remains on until the next oscillator pulse discharges the PWM
ramp.
During transient conditions, the error amplifier output could be below the PWM ramp valley voltage or above
the PWM peak voltage. If the error amplifier is high, the PWM latch is never reset, and the high-side FET remains
on until the oscillator pulse signals the control logic to turn the high-side FET off and the low-side FET on. The
device operates at its maximum duty cycle until the output voltage rises to the regulation set-point, setting
VSENSE to approximately the same voltage as V
ref
. If the error amplifier output is low, the PWM latch is
continually reset and the high-side FET does not turn on. The low-side FET remains on until the VSENSE
voltage decreases to a range that allows the PWM comparator to change states. The TPS54611
–
TPS54616
devices are capable of sinking current continuously until the output reaches the regulation set-point.
If the current limit comparator trips for longer than 100 ns, the PWM latch resets before the PWM ramp exceeds
the error amplifier output. The high-side FET turns off and the low-side FET turns on to decrease the energy
in the output inductor and consequently decrease the output current. This process is repeated each cycle in
which the current limit comparator is tripped.
(3)
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| TPS54673PWP | SMPS Controller |
| TPS54673PWPR | SMPS Controller |
| TPS54680PWPR | SMPS Controller |
| TPS54311PWPR | Analog IC |
| TPS54312PWPR | Analog IC |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| TPS54672PWPR | 制造商:Texas Instruments 功能描述:IC SYNC PWM SWITCHER |
| TPS54672PWPRG4 | 功能描述:直流/直流開關(guān)調(diào)節(jié)器 6-A Act Bus Term/DDR DC/DC Converter RoHS:否 制造商:International Rectifier 最大輸入電壓:21 V 開關(guān)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(shù)量: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFN 4 x 5 |
| TPS54672PWRG4 | 制造商:Texas Instruments 功能描述: |
| TPS54673 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:3-V TO 6-V INPUT, 6-A OUTPUT SYNCHRONOUS BUCK PWM SWITCHER WITH INTEGRATED FETs |
| TPS54673EVM | 功能描述:電源管理IC開發(fā)工具 6-A 3.3/5 Vin DC/DC Conv RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評(píng)估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。