外文翻譯---max232-5v的供電，多通道rs-232接口驅(qū)動器接收器-展示頁
2025-01-26 23:34本頁面
【正文】 e MAX220–MAX249 have two internal chargepumps that convert +5V to 177。5V EIA/TIA232E driver output voltage when sourcing current from V+ and V to external circuitry.When using the shutdown feature in the MAX222,MAX225, MAX230, MAX235, MAX236, MAX240,MAX241, and MAX245–MAX249, avoid using V+ and V to power external circuitry. When these parts are shut down, V falls to 0V, and V+ falls to +5V. For applications where a +10V external supply is applied to the V+ pin (instead of using the internal charge pump to generate +10V), the C1 capacitor must not be installed and the SHDN pin must be tied to VCC. This is because V+ is internally connected to VCC in shutdown mode.RS232 DriversThe typical driver output voltage swing is 177。5V minimum driver output levels under worstcase conditions. These include a minimum 3kΩ load, VCC = +, and maximum operating temperature. Unloaded driver output voltage ranges from (V+ ) to (V +).Input thresholds are both TTL and CMOS inputs of unused drivers can be left unconnected since 400kΩ input pullup resistors to VCC are built in (except for the MAX220). The pullup resistors force theoutputs of unused drivers low because all drivers internal input pullup resistors typically source 12μA, except in shutdown mode where the pullups are outputs turn off and enter a highimpedance state—where leakage current is typically microamperes (maximum 25μA)—when in shutdown mode, in threestate mode, or when device power is removed. Outputs can be driven to 177。25V and provide input terminating resistors with nominal 5kΩ values. The receivers implement Type 1 interpretation of the fault conditions of and EIA/TIA232E. The receiver input hysteresis is typically with a guaranteed minimum of . This produces clear output transitions with slowmoving input signals, even with moderate amounts of noise and ringing. The receiver propagation delay is typically 600ns and is independent of input swing direction.LowPower Receive ModeThe lowpower receivemode feature of the MAX223, MAX242, and MAX245–MAX249 puts the IC into shutdown mode but still allows it to receive information. This is important for applications where systems are periodically awakened to look for activity. Using lowpower receive mode, the system can still rec
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