參數(shù)資料
型號: UC3827DWTR-2
廠商: Texas Instruments, Inc.
英文描述: TVS, S/M, QUAD, SOT23-6L, 5V
中文描述: 降壓電流/電壓美聯(lián)儲推挽式PWM控制器
文件頁數(shù): 7/15頁
文件大?。?/td> 283K
代理商: UC3827DWTR-2
www.ti.com
APPLICATION INFORMATION
+
RT
CT
SYNC
S
R
V
REF
2.5 V
OSCILLATOR
V
REF
10 k
1.4 V
2.5 V
2.9 V
0.5 V
R
T
C
T
VDG99086
CIRCUIT BLOCK DESCRIPTION
PWM Oscillator
I
RT
2.5 V
R
RT
(1)
UC1827-1, UC1827-2
UC2827-1, UC2827-2
UC3827-1, UC3827-2
SLUS365A–APRIL 1999–REVISED AUGUST 2005
Figure 1. Oscillator Block With External Connections
The oscillator block diagram with external connections is shown in
Equation 1
. A resistor (R
T
) connected to pin
RT sets the linear charge current:
The timing capacitor (C
CT
) is linearly charged with the charge current forcing the OSC pin to charge to a 3.4 V
threshold. After exceeding this threshold, the RS flip-flop is set driving CLKSYN high and R
DEAD
low which
discharges C
CT
. CT continues to discharge until it reaches a 0.5 V threshold and resets the RS flip-flop which
repeats the charging sequence as shown in
Figure 2
As shown in
Figure 3
, several oscillators are synchronized to the highest free running frequency by connecting
100 pF capacitors in series with each CLKSYN pin and connecting the other side of the capacitors together
forming the CLKSYN bus. The CLKSYN bus is then pulled down to ground with a resistance of approximately
10k. Referring to
Figure 1
, the synchronization threshold is 1.4 V. The oscillator blanks any synchronization pulse
that occurs when OSC is below 2.5 V. This allows units, once they discharge below 2.5 V, to continue through
the current discharge and subsequent charge cycles whether or not other units on the CLKSYN bus are still
synchronizing. This requires the frequency of all free running oscillators to be within 17% of each other to assure
synchronization.
7
相關(guān)PDF資料
PDF描述
UC3827DWTR-2G4 Buck Current/Voltage Fed Push-Pull PWM Controllers
UC1827 Buck Current/Voltage Fed Push-Pull PWM Controllers
UC1827- Buck Current/Voltage Fed Push-Pull PWM Controllers
UC1827-2 Buck Current/Voltage Fed Push-Pull PWM Controllers
UC1827J-2 Buck Current/Voltage Fed Push-Pull PWM Controllers
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
UC3827DWTR-2G4 功能描述:電流型 PWM 控制器 Buck Current/Voltage Fed Push-Pull RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
UC3827N-1 功能描述:電流型 PWM 控制器 Buck Current/Voltage Fed Push-Pull RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
UC3827N-1 制造商:Texas Instruments 功能描述:IC PWM CONTROLLER 3827 DIP24
UC3827N-1G4 功能描述:電流型 PWM 控制器 Buck Crnt/Vltg Fed Push-Pull PWM Cntrlr RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14
UC3827N-2 功能描述:電流型 PWM 控制器 Buck Current/Voltage Fed Push-Pull RoHS:否 制造商:Texas Instruments 開關(guān)頻率:27 KHz 上升時間: 下降時間: 工作電源電壓:6 V to 15 V 工作電源電流:1.5 mA 輸出端數(shù)量:1 最大工作溫度:+ 105 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TSSOP-14