UC3844B: High Performance Current Mode PWM Controller
The UC3844B, UC3845B series are high performance fixed frequency current mode controllers. They are specifically designed for Off-Line and dc-to-dc converter applications offering the designer a cost-effective 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, cycle-by-cycle current limiting, a latch for single pulse metering, and a flip-flop 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 8-pin dual-in-line and surface mount (SO-8) plastic package as well as the 14-pin plastic surface mount (SO-14). The SO-14 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 off-line converters. The UCX845B is tailored for lower voltage applications having UVLO thresholds of 8.5 V (on) and 7.6 V (off).
技术特性
- 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 Cycle−By−Cycle Current Limiting
- Internally Trimmed Reference with Undervoltage Lockout
- High Current Totem Pole Output
- Undervoltage Lockout with Hysteresis
- Low Startup and Operating Current
- These Devices are Pb−Free and are RoHS Compliant
- NCV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC−Q100 Qualified and PPAP Capable
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封装图 PACKAGE DIMENSIONS
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订购信息 Ordering Information
| 产品 |
状况 |
Compliance |
具体说明 |
封装 |
MSL* |
容器 |
预算价格 (1千个数量的单价） |
| 类型 |
外形 |
类型 |
数量 |
| UC3844BD1G |
Active |
|
High Performance Current Mode PWM Controller |
SOIC-8 |
751-07 |
1 |
Tube |
98 |
$0.432 |
| UC3844BD1R2G |
Active |
|
High Performance Current Mode PWM Controller |
SOIC-8 |
751-07 |
1 |
Tape and Reel |
2500 |
$0.432 |
| UC3844BDG |
Active |
|
High Performance Current Mode PWM Controller |
SOIC-14 |
751A-03 |
1 |
Tube |
55 |
$0.432 |
| UC3844BDR2G |
Active |
|
High Performance Current Mode PWM Controller |
SOIC-14 |
751A-03 |
1 |
Tape and Reel |
2500 |
$0.432 |
| UC3844BNG |
Active |
|
High Performance Current Mode PWM Controller |
PDIP-8 |
626-05 |
|
Tube |
50 |
$0.432 |
| UC3844BVD1G |
Active |
|
High Performance Current Mode PWM Controller |
SOIC-8 |
751-07 |
1 |
Tube |
98 |
$0.5733 |
| UC3844BVD1R2G |
Active |
|
High Performance Current Mode PWM Controller |
SOIC-8 |
751-07 |
1 |
Tape and Reel |
2500 |
$0.5733 |
| UC3844BVDG |
Active |
|
High Performance Current Mode PWM Controller |
SOIC-14 |
751A-03 |
1 |
Tube |
55 |
$0.5733 |
| UC3844BVDR2G |
Active |
|
High Performance Current Mode PWM Controller |
SOIC-14 |
751A-03 |
1 |
Tape and Reel |
2500 |
$0.5733 |
| UC3844BVNG |
Active |
|
High Performance Current Mode PWM Controller |
PDIP-8 |
626-05 |
|
Tube |
50 |
$0.5733 |
数据资料DataSheet下载
