TL3845B
- Low Start-Up Current (<0.5 mA)
- Trimmed Oscillator Discharge Current
- Current Mode Operation to 500 kHz
- 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
- Double-Pulse Suppression
The TL284xB and TL384xB series of control integrated circuits provide the features that are necessary to implement off-line or dc-to-dc fixed-frequency current-mode control schemes, with a minimum number of external components. Internally implemented circuits include an undervoltage lockout (UVLO) and a precision reference that is trimmed for accuracy at the error amplifier input. Other internal circuits include logic to ensure latched operation, a pulse-width modulation (PWM) comparator that 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 when it is in the off state.
The TL284xB and TL384xB series are pin compatible with the standard TL284x and TL384x with the following improvements. The start-up current is specified to be 0.5 mA (max), while the oscillator discharge current is trimmed to 8.3 mA (typ). In addition, during undervoltage lockout conditions, the output has a maximum saturation voltage of 1.2 V while sinking 10 mA (VCC = 5 V).
Major differences between members of these series are the UVLO thresholds and maximum duty-cycle ranges. Typical UVLO thresholds of 16 V (on) and 10 V (off) on the TLx842B and TLx844B devices make them ideally suited to off-line applications. The corresponding typical thresholds for the TLx843B and TLx845B devices are 8.4 V (on) and 7.6 V (off). The TLx842B and TLx843B devices can operate to duty cycles approaching 100%. A duty-cycle range of 0% to 50% is obtained by the TLx844B and TLx845B by the addition of an internal toggle flip-flop, which blanks the output off every other clock cycle.The TL284xB-series devices are characterized for operation from -40°C to 85°C. The TL384xB-series devices are characterized for operation from 0°C to 70°C.
技術文件
類型 | 標題 | 日期 | ||
---|---|---|---|---|
* | Data sheet | High Performance Current-Mode PWM Controllers datasheet (Rev. B) | 2007年 7月 2日 | |
Selection guide | Power Management Guide 2018 (Rev. R) | 2018年 6月 25日 |
設計與開發
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封裝 | 針腳 | CAD 符號、佔位空間與 3D 模型 |
---|---|---|
PDIP (P) | 8 | Ultra Librarian |
SOIC (D) | 14 | Ultra Librarian |
SOIC (D) | 8 | Ultra Librarian |
訂購與品質
- RoHS
- REACH
- 產品標記
- 鉛塗層/球物料
- MSL 等級/回焊峰值
- MTBF/FIT 估算值
- 材料內容
- 認證摘要
- 進行中持續性的可靠性監測
- 晶圓廠位置
- 組裝地點