UC3845 电流模式 PWM 控制器
UC3845 描述
The UC1842/3/4/5 family of control devices provides the necessary features to implement off-line or dc-to-dc fixed frequency current mode control schemes with a minimal external parts count. Internally implemented circuits include under-voltage lockout featuring start up current less than 1 mA, a precision reference trimmed for accuracy at the error amp input, logic to insure latched operation, a PWM comparator which also provides current limit control, and a totem pole output stage designed to source or sink high peak current. The output stage, suitable for driving N-Channel MOSFETs, is low in the off state.
Differences between members of this family are the under-voltage lockout thresholds and maximum duty cycle ranges.
| |
UC1845 |
UC2845 |
UC3845 |
| Topology |
Boost, Flyback, Forward |
Boost, Flyback, Forward |
Boost, Buck, Flyback, Forward |
| Control Method |
Current Mode |
Current Mode |
Current Mode |
| Duty Cycle(Max)(%) |
50 |
50 |
50 |
| Frequency(Max)(kHz) |
450 |
450 |
450 |
| UVLO Thresholds On/Off(V) |
8.4/7.6 |
8.4/7.6 |
8.4/7.6 |
| Pin/Package |
14CFP, 20LCCC, 8CDIP |
14SOIC, 8PDIP, 8SOIC |
14SOIC, 8PDIP, 8SOIC |
| Regulated Outputs(#) |
1 |
1 |
1 |
| Operating Temperature Range(°C) |
-55 to 125 |
-40 to 85 |
0 to 70 |
| Rating |
Military |
Military |
Catalog |
UC3845 特性
- Optimized For Off-line and DC-to-DC Converters
- Low Start-Up Current (<1 mA)
- Automatic Feed ForwardCompensation
- Pulse-by-Pulse Current Limiting
- Enhanced Load Response Characteristics
- Under-Voltage Lockout With Hysteresis
- Double Pulse Suppression
- High Current Totem Pole Output
- Internally Trimmed Bandgap Reference
- 500-kHz Operation
- Low RO Error Amp
UC3845 芯片订购指南
| 器件 |
状态 |
温度 (oC) |
价格（美元） |
封装 | 引脚 |
封装数量 | 封装载体 |
丝印标记 |
| UC3845D |
ACTIVE |
0 to 70 |
0.90 | 1ku |
SOIC (D) | 14 |
50 | TUBE |
UC3845D |
| UC3845D8 |
ACTIVE |
0 to 70 |
0.90 | 1ku |
SOIC (D) | 8 |
75 | TUBE |
UC3845D |
| UC3845D8G4 |
ACTIVE |
0 to 70 |
0.90 | 1ku |
SOIC (D) | 8 |
75 | TUBE |
UC3845D |
| UC3845D8TR |
ACTIVE |
0 to 70 |
0.90 | 1ku |
SOIC (D) | 8 |
2500 | LARGE T&R |
UC3845D |
| UC3845D8TRG4 |
ACTIVE |
0 to 70 |
0.90 | 1ku |
SOIC (D) | 8 |
2500 | LARGE T&R |
UC3845D |
| UC3845DG4 |
ACTIVE |
0 to 70 |
0.90 | 1ku |
SOIC (D) | 14 |
50 | TUBE |
UC3845D |
| UC3845DTR |
ACTIVE |
0 to 70 |
0.90 | 1ku |
SOIC (D) | 14 |
2500 | LARGE T&R |
UC3845D |
| UC3845DTRG4 |
ACTIVE |
0 to 70 |
0.90 | 1ku |
SOIC (D) | 14 |
2500 | LARGE T&R |
UC3845D |
| UC3845N |
ACTIVE |
0 to 70 |
0.90 | 1ku |
PDIP (P) | 8 |
50 | TUBE |
UC3845N |
| UC3845NG4 |
ACTIVE |
0 to 70 |
0.90 | 1ku |
PDIP (P) | 8 |
50 | TUBE |
UC3845N |
| UC3845P |
OBSOLETE |
0 to 70 |
|
PDIP (P) | 8 |
|
UC3845P |
UC3845 质量与无铅数据
| 器件 |
环保计划* |
铅/焊球涂层 |
MSL 等级/回流焊峰 |
环保信息与无铅 (Pb-free) |
DPPM / MTBF / FIT 率 |
| UC3845D |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
Level-1-260C-UNLIM |
|
UC3845D |
| UC3845D8 |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
Level-1-260C-UNLIM |
|
UC3845D8 |
| UC3845D8G4 |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
Level-1-260C-UNLIM |
UC3845D8G4 |
UC3845D8G4 |
| UC3845D8TR |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
Level-1-260C-UNLIM |
|
UC3845D8TR |
| UC3845D8TRG4 |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
Level-1-260C-UNLIM |
UC3845D8TRG4 |
UC3845D8TRG4 |
| UC3845DG4 |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
Level-1-260C-UNLIM |
UC3845DG4 |
UC3845DG4 |
| UC3845DTR |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
Level-1-260C-UNLIM |
|
UC3845DTR |
| UC3845DTRG4 |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
Level-1-260C-UNLIM |
UC3845DTRG4 |
UC3845DTRG4 |
| UC3845N |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
N/A for Pkg Type |
|
UC3845N |
| UC3845NG4 |
Green (RoHS & no Sb/Br) |
CU NIPDAU |
N/A for Pkg Type |
UC3845NG4 |
UC3845NG4 |
UC3845 应用技术支持与电子电路设计开发资源下载
- UC3845 数据资料 dataSheet 下载.PDF
- TI 德州仪器AC/DC 和 DC/DC 电源产品选型与价格参考 . xls
- Dual MOSFET Driver
(PDF 498 KB)
- 标准线性产品交叉参考 (Rev. D)
(PDF 1058 KB)
- 模数规格和性能特性术语表 (Rev. A) (PDF 1993 KB)
- 所选封装材料的热学和电学性质 (PDF 645 KB)
- 高速数据转换 (PDF 1967 KB)
- Shelf-Life Evaluation of Lead-Free Component Finishes (PDF
1305 KB)
- Analog-to-Digital Converter Grounding Practices Affect System
Performance (PDF 56 KB)
- Principles of Data Acquisition and Conversion (PDF 50 KB)
- Interleaving Analog-to-Digital Converters (PDF 64 KB)
- What
Designers Should Know About Data Converter Drift (PDF 95 KB)
- Giving Delta-Sigma Converters a Gain Boost with a Front End
Analog Gain Stage (PDF 70 KB)
- Programming Tricks for Higher Conversion Speeds Utilizing Delta
Sigma Converters (PDF 105 KB)
UC3845 工具与软件