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The UC284xB family of control ICs 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 a trimmed oscillator for precise DUTY CYCLE CONTROL under voltage lockout featuring start-up current less than 0.5mA, 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. The UC2842B and UC2844B have UVLO thresholds of 16V (on) and 10V (off), ideally suited off-line applications The corresponding thresholds for the UC2843B and UC2845B are 8.5V and 7.9V. The UC2842B and UC2843B can operate to duty cycles approaching 100%. A range of the zero to < 50 % is obtained by the UC2844B and UC2845B by the addition of an internal toggle flip flop which blanks the output off every other clock cycle.
主な特徴
- LOW START-UP AND OPERATING CURRENT
- UNDERVOLTAGE LOCKOUT WITH HYSTERESIS
- INTERNALLY TRIMMED REFERENCE WITH UNDERVOLTAGE LOCKOUT
- CURRENT LIMITING
- TRIMMED OSCILLATOR FOR PRECISE FREQUENCY CONTROL
- CURRENT MODE OPERATION TO 500kHz
- OSCILLATOR FREQUENCY GUARANTEED AT 250kHz
- LATCHING PWM FOR CYCLE-BY-CYCLE
- HIGH CURRENT TOTEM POLE OUTPUT
- AUTOMATIC FEED FORWARD COMPENSATION
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サンプル & 購入
| 製品型番 | パッケージ | 梱包タイプ | 製品ステータス | 概算価格（USS） | 数量 | ECCN (US) | Country of Origin | 販売代理店からオーダー | STからオーダー |
|---|---|---|---|---|---|---|---|---|---|
| UC3845BN | DIP-8 | Tube | アクティブ | 0.2772 | 1000 | EAR99 | - | 在庫チェック | 購入 |
| UC3845BD1 | SO-8 | Tube | アクティブ | 0.2772 | 1000 | EAR99 | MOROCCO | 在庫チェック | 購入 |
| UC3845BD1013TR | SO-8 | Tape And Reel | アクティブ | 0.2772 | 1000 | EAR99 | MOROCCO | 在庫チェック | 購入 |
(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office or our Distributors
ビデオ
| 製品型番 | 製品ステータス | パッケージ | グレード | RoHSコンプライアンスグレード | Material Declaration** |
|---|---|---|---|---|---|
| UC3845BD1 | アクティブ | SO-8 | インダストリアル | Ecopack2 | |
| UC3845BD1013TR | アクティブ | SO-8 | インダストリアル | Ecopack2 | |
| UC3845BN | アクティブ | DIP-8 | インダストリアル | Ecopack2 |
(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.
