产品应用与封装尺寸
图纸取自原厂规格书，点击可放大查看原始尺寸标注。
引脚定义与内部结构
| 引脚 | 符号 | 名称 |
|---|---|---|
| 7 | V | |
| 8 | D1 | |
| 9 | GND | |
| 10 | V | |
| 11 | V | |
| 12 | V | |
| 13 | NC | |
| 14 | V | |
| 15 | V | |
| 16 | V |
数据来源：原厂规格书引脚图
产品特点 Features
- reference, high gain error amplifier, current sensing comparator, and a N SUFFIX high current totem pole output ideally suited for driving a power CASE 626
- MOSFET.
- CASE 751 output deadtimes to be programmed from 50% to 70%.
- These devices are available in an 8−pin dual−in−line and surface mount (SOIC−8) plastic package as well as the 14−pin plastic surface mount (SOIC−14). The SOIC−14 package has separate power and
- SOIC−14 ground pins for the totem pole output stage.
- D SUFFIX
- The UCX844B has UVLO thresholds of 16 V (on) and 10 V (off), CASE 751A ideally suited for off−line converters. The UCX845B is tailored for
- Compensation 1 8 V ref
- Pb−Free Packages are Available Voltage Feedback 2 7 V CC
- Current Sense 3 6 Output
- Trimmed Oscillator for Precise Frequency Control
- R T /C T 4 5 GN
- Oscillator Frequency Guaranteed at 250 kHz D
- (Top View)
- Current Mode Operation to 500 kHz Output Switching Frequency
- Output Deadtime Adjustable from 50% to 70% Compensation 1 14 V ref
绝对最大额定值 Absolute Maximum Ratings（TA = 25°C）
超过下表数值可能造成器件永久损坏，设计时请留余量。
| 额定值 | 符号 | 值 | 单位 |
|---|---|---|---|
| Output Current, Source or Sink (Note 1) | I | 1.0 | A |
| Output Energy (Capacitive Load per Cycle) | W | 5.0 | µJ |
| Error Amp Output Sink Current | I | 10 | mA |
| D Suffix, Plastic Package, SOIC−14 Case 751A | |||
| Maximum Power Dissipation @ T = 25°C | P | 862 | mW |
| Thermal Resistance, Junction−to−Air | RJA | 145 | °C/W |
| D1 Suffix, Plastic Package, SOIC−8 Case 751 | |||
| Maximum Power Dissipation @ T = 25°C | P | 702 | mW |
| Thermal Resistance, Junction−to−Air | RJA | 178 | °C/W |
| N Suffix, Plastic Package, Case 626 | |||
| Maximum Power Dissipation @ T = 25°C | P | 1.25 | W |
| Thermal Resistance, Junction−to−Air | RJA | 100 | °C/W |
| Operating Junction Temperature | T | +150 | °C |
| Operating Ambient Temperature | T | °C | |
| UC3844B, UC3845B | 0 to + 70 | ||
| UC2844B, UC2845B | − 25 to + 85 | ||
| Storage Temperature Range | T | − 65 to +150 | °C |
| CC T | T | A | |
| UC284XB | UC384XB, XBV | ||
| Reference Output Voltage (I = 1.0 mA, T = 25°C) V | 4.95 5.0 5.05 | 4.9 5.0 | 5.1 V |
| Line Regulation (V = 12 V to 25 V) Reg | − 2.0 20 | − 2.0 | 20 mV |
| Load Regulation (I = 1.0 mA to 20 mA) Reg | − 3.0 25 | − 3.0 | 25 mV |
| Temperature Stability T | − 0.2 − | − 0.2 | − mV/°C |
| Output Noise Voltage (f = 10 Hz to 10 kHz, T = 25°C) V | − 50 − | − 50 | − µV |
| Long Term Stability (T = 125°C for 1000 Hours) | S − 5.0 − | − 5.0 | − mV |
| Output Short Circuit Current I | − 30 − 85 −180 | − 30 − 85 | −180 mA |
| Frequency f | kHz | ||
| T = 25°C | 49 52 55 | 49 52 | 55 |
| T = T to T | 48 − 56 | 48 − | 56 |
| T = 25°C (R = 6.2 k, C = 1.0 nF) | 225 250 275 | 225 250 | 275 |
| Frequency Change with Voltage (V = 12 V to 25 V) Ωf | /ΩV − 0.2 1.0 | − 0.2 | 1.0 % |
| Frequency Change with Temperature (T = T to T ) Ωf | /ΩT − 1.0 − | − 0.5 | − % |
| Oscillator Voltage Swing (Peak−to−Peak) V | − 1.6 − | − 1.6 | − V |
| Discharge Current (V = 2.0 V) I | mA | ||
| T = 25°C | 7.8 8.3 8.8 | 7.8 8.3 | 8.8 |
| T = T to T (UC284XB, UC384XB) | 7.5 − 8.8 | 7.6 − | 8.8 |
| T = T to T (UC384XBV) | − − − | 7.2 − | 8.8 |
| T = 0°C for UC3844B, UC3845B T = + 70°C for | UC3844B, UC3845B | ||
| = − 25°C for UC2844B, UC2845B = + 85°C for | UC2844B, UC2845B | ||
| = − 40°C for UC3844BV, UC3845BV = +105°C for | UC3844BV, UC3845BV |
数据来源：原厂规格书
订货信息与供货形式
| See | detailed | ordering | and | 包装 | information | in | the | 封装 |
|---|---|---|---|---|---|---|---|---|
| See | detailed | ordering | and | shipping | information | in | the | package |
| See | general | marking | information | in the | device | marking |