參數(shù)資料
型號(hào): UC2844B
廠商: ON SEMICONDUCTOR
英文描述: High Performance Current Mode Controllers(高性能電流模式控制器)
中文描述: 高性能電流模式控制器(高性能電流模式控制器)
文件頁(yè)數(shù): 1/18頁(yè)
文件大?。?/td> 400K
代理商: UC2844B
Semiconductor Components Industries, LLC, 2005
November, 2005 Rev. 4
1
Publication Order Number:
UC3844B/D
UC3844B, UC3845B,
UC2844B, UC2845B
High Performance
Current Mode Controllers
The UC3844B, UC3845B series are high performance fixed frequency
current mode controllers. They are specifically designed for OffLine
and dcdc converter applications offering the designer a costeffective
solution with minimal external components. These integrated circuits
feature an oscillator, a temperature compensated reference, high gain
error amplifier, current sensing comparator, and a high current totem pole
output ideally suited for driving a power MOSFET.
Also included are protective features consisting of input and reference
undervoltage lockouts each with hysteresis, cyclebycycle current
limiting, a latch for single pulse metering, and a flipflop which blanks
the output off every other oscillator cycle, allowing output deadtimes to
be programmed from 50% to 70%.
These devices are available in an 8pin dualinline and surface
mount (SOIC8) plastic package as well as the 14pin plastic surface
mount (SOIC14). The SOIC14 package has separate power and
ground pins for the totem pole output stage.
The UCX844B has UVLO thresholds of 16 V (on) and 10 V (off),
ideally suited for offline converters. The UCX845B is tailored for
lower voltage applications having UVLO thresholds of 8.5 V (on) and
7.6 V (off).
Features
Trimmed Oscillator for Precise Frequency Control
Oscillator Frequency Guaranteed at 250 kHz
Current Mode Operation to 500 kHz Output Switching Frequency
Output Deadtime Adjustable from 50% to 70%
Automatic Feed Forward Compensation
Latching PWM for CycleByCycle Current Limiting
Internally Trimmed Reference with Undervoltage Lockout
High Current Totem Pole Output
Undervoltage Lockout with Hysteresis
Low Startup and Operating Current
PbFree Packages are Available
Pin numbers in parenthesis are for the D suffix SOIC14 package.
Figure 1. Simplified Block Diagram
Output
V
C
R
T
/C
T
V
ref
V
Undervoltage
Lockout
GND
5.0V
Reference
V
ref
Undervoltage
Lockout
Latching
PWM
Oscillator
Error
Amplifier
5(9)
3(5)
5(8)
6(10)
Power
Ground
7(11)
Current
Sense Input
1(1)
2(3)
4(7)
8(14)
Output/
Compensation
Voltage
Feedback
Input
V
CC
7(12)
R
R
14
SOIC14
D SUFFIX
CASE 751A
1
See detailed ordering and shipping information in the package
dimensions section on page 15 of this data sheet.
ORDERING INFORMATION
See general marking information in the device marking
section on page 16 of this data sheet.
DEVICE MARKING INFORMATION
1
8
PDIP8
N SUFFIX
CASE 626
PIN CONNECTIONS
Compensation
NC
Voltage Feedback
NC
Current Sense
NC
R
T
/C
T
Compensation
Voltage Feedback
Current Sense
R
T
/C
T
V
ref
V
CC
Output
GN
D
V
ref
NC
V
CC
V
C
Output
GND
Power Ground
(Top View)
8
7
6
5
1
2
3
4
1
2
3
4
14
13
12
11
5
6
7
10
9
8
(Top View)
SOIC8
D1 SUFFIX
CASE 751
1
8
http://onsemi.com
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
UC2844BAC 制造商:ONSEMI 制造商全稱:ON Semiconductor 功能描述:HIGH PERFORMANCE CURRENT MODE CONTROLLERS
UC2844BD 制造商:ONSEMI 制造商全稱:ON Semiconductor 功能描述:HIGH PERFORMANCE CURRENT MODE CONTROLLERS
UC2844BD1 功能描述:電流型 PWM 控制器 0.5mA Current Mode RoHS:否 制造商:Texas Instruments 開(kāi)關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)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
UC2844BD1013TR 功能描述:電流型 PWM 控制器 0.5mA Current Mode RoHS:否 制造商:Texas Instruments 開(kāi)關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)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
UC2844BD1R2 功能描述:電流型 PWM 控制器 52kHz 1A Current PWM RoHS:否 制造商:Texas Instruments 開(kāi)關(guān)頻率:27 KHz 上升時(shí)間: 下降時(shí)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