The MAX3224–MAX3227/MAX3244/MAX3245 are 3V-powered EIA/TIA-232 and V.28/V.24 communications interfaces with automatic shutdown/wakeup features and high data-rate capabilities.All devices achieve a 1µA supply current using Maxim's revolutionary AutoShutdown Plus™ feature. These devices automatically enter a low-power shutdown mode when the RS-232 cable is disconnected or the transmitters of the connected peripherals are inactive, and the UART driving the transmitter inputs is inactive for more than 30 seconds. They turn on again when they sense a valid transition at any transmitter or receiver input. AutoShutdown Plus saves power without changes to the existing BIOS or operating system.The MAX3225/MAX3227/MAX3245 also feature MegaBaud™ operation, guaranteeing 1Mbps for highspeed applications such as communicating with ISDN modems. The MAX3224/MAX3226/MAX3244 guarantee 250kbps operation. The transceivers have a proprietary low-dropout transmitter output stage enabling true RS-232 performance from a +3.0V to +5.5V supply with a dual charge pump. The charge pump requires only four small 0.1µF capacitors for operation from a 3.3V supply. The MAX3224-MAX3227 feature a logic-level output (READY) that asserts when the charge pump is regulating and the device is ready to begin transmitting.All devices are available in a space-saving TSSOP and SSOP packages.ApplicationsBattery-Powered EquipmentCell PhonesHandheld EquipmentNotebook, Subnotebook, and Palmtop ComputersPeripheralsPrinters

The MAX3224E/MAX3225E/MAX3226E/MAX3227E/MAX3244E/MAX3245E are 3V-powered EIA/TIA-232 and V.28/V.24 communications interfaces with automatic shutdown/wakeup features, high data-rate capabilities, and enhanced electrostatic discharge (ESD) protection. All transmitter outputs and receiver inputs are protected to ±15kV using IEC 1000-4-2 Air-Gap Discharge, ±8kV using IEC 1000-4-2 Contact Discharge, and ±15kV using the Human Body Model.All devices achieve a 1µA supply current using Maxim's revolutionary AutoShutdown Plus™ feature. These devices automatically enter a low-power shutdown mode when the RS-232 cable is disconnected or the transmitters of the connected peripherals are inactive, and the UART driving the transmitter inputs is inactive for more than 30 seconds. They turn on again when they sense a valid transition at any transmitter or receiver input. AutoShutdown Plus saves power without changes to the existing BIOS or operating system.The MAX3225E/MAX3227E/MAX3245E also feature MegaBaud™ operation, guaranteeing 1Mbps for high-speed applications such as communicating with ISDN modems. The MAX3224E/MAX3226E/MAX3244E guarantee 250kbps operation. The transceivers have a proprietary low-dropout transmitter output stage enabling true RS-232 performance from a +3.0V to +5.5V supply with a dual charge pump. The charge pump requires only four small 0.1µF capacitors for operation from a 3.3V supply. The MAX3224E–MAX3227E feature a logic-level output (READY) that asserts when the charge pump is regulating and the device is ready to begin transmitting.All devices are available in a space-saving TQFN, SSOP, and TSSOP (MAX3224E/MAX3225E/MAX3244E/MAX3245E) packages.ApplicationsAutomotiveBattery-Powered EquipmentCellular PhonesHandheld EquipmentNotebook, Subnotebook, and Palmtop ComputersPeripheralsPrinters

The MAX3224E/MAX3225E/MAX3226E/MAX3227E/MAX3244E/MAX3245E are 3V-powered EIA/TIA-232 and V.28/V.24 communications interfaces with automatic shutdown/wakeup features, high data-rate capabilities, and enhanced electrostatic discharge (ESD) protection. All transmitter outputs and receiver inputs are protected to ±15kV using IEC 1000-4-2 Air-Gap Discharge, ±8kV using IEC 1000-4-2 Contact Discharge, and ±15kV using the Human Body Model.All devices achieve a 1µA supply current using Maxim's revolutionary AutoShutdown Plus™ feature. These devices automatically enter a low-power shutdown mode when the RS-232 cable is disconnected or the transmitters of the connected peripherals are inactive, and the UART driving the transmitter inputs is inactive for more than 30 seconds. They turn on again when they sense a valid transition at any transmitter or receiver input. AutoShutdown Plus saves power without changes to the existing BIOS or operating system.The MAX3225E/MAX3227E/MAX3245E also feature MegaBaud™ operation, guaranteeing 1Mbps for high-speed applications such as communicating with ISDN modems. The MAX3224E/MAX3226E/MAX3244E guarantee 250kbps operation. The transceivers have a proprietary low-dropout transmitter output stage enabling true RS-232 performance from a +3.0V to +5.5V supply with a dual charge pump. The charge pump requires only four small 0.1µF capacitors for operation from a 3.3V supply. The MAX3224E–MAX3227E feature a logic-level output (READY) that asserts when the charge pump is regulating and the device is ready to begin transmitting.All devices are available in a space-saving TQFN, SSOP, and TSSOP (MAX3224E/MAX3225E/MAX3244E/MAX3245E) packages.ApplicationsAutomotiveBattery-Powered EquipmentCellular PhonesHandheld EquipmentNotebook, Subnotebook, and Palmtop ComputersPeripheralsPrinters

The MAX3291/MAX3292 high-speed RS-485/RS-422 transceivers feature driver preemphasis circuitry, which extends the distance and increases the data rate of reliable communication by reducing intersymbol interference (ISI) caused by long cables. The MAX3291 is programmable for data rates of 5Mbps to 10Mbps, while the MAX3292 is programmable for data rates up to 10Mbps by using a single external resistor.The MAX3291/MAX3292 are full-duplex devices that operate from a single +5V supply and offer a low-current shutdown mode that reduces supply current to 100nA. They feature driver output short-circuit current limiting and a fail-safe receiver input that guarantees a logic-high output if the input is open circuit. A 1/4-unit-load receiver input impedance allows up to 128 transceivers on the bus.ApplicationsIndustrial Control Local Area NetworksLong-Distance, High-Speed RS-485/RS-422 CommunicationsTelecommunications

The MAX3320 combines a microprocessor (µP) supervisory circuit with an RS-232 transceiver. The power-on reset performs a single function: it asserts a reset signal whenever the VCC supply voltage declines below a preset threshold, staying asserted for at least 100ms after VCC rises above the reset threshold. The MAX3320 has an active-low RESET output, which is guaranteed to be in the correct state for VCC down to 1V. The reset comparator is designed to ignore fast transients on VCC. Reset thresholds suitable for operation with a variety of supply voltages are available.The MAX3320 transceivers have a proprietary low-dropout transmitter output stage, enabling true RS-232 performance with a dual charge pump powered from a +3V to +5.5V supply. The device requires only four small 0.1µF external charge-pump capacitors, and is guaranteed to run at data rates of up to 250kbps. It comes in the space-saving 20-pin SSOP package.ApplicationsHandheld EquipmentPalmtop ComputersPeripheralsPortable Battery-Powered EquipmentPrinters

The MAX3320 combines a microprocessor (µP) supervisory circuit with an RS-232 transceiver. The power-on reset performs a single function: it asserts a reset signal whenever the VCC supply voltage declines below a preset threshold, staying asserted for at least 100ms after VCC rises above the reset threshold. The MAX3320 has an active-low RESET output, which is guaranteed to be in the correct state for VCC down to 1V. The reset comparator is designed to ignore fast transients on VCC. Reset thresholds suitable for operation with a variety of supply voltages are available.The MAX3320 transceivers have a proprietary low-dropout transmitter output stage, enabling true RS-232 performance with a dual charge pump powered from a +3V to +5.5V supply. The device requires only four small 0.1µF external charge-pump capacitors, and is guaranteed to run at data rates of up to 250kbps. It comes in the space-saving 20-pin SSOP package.ApplicationsHandheld EquipmentPalmtop ComputersPeripheralsPortable Battery-Powered EquipmentPrinters

The MAX481E, MAX483E, MAX485E, MAX487E-MAX491E, and MAX1487E are low-power transceivers forRS-485 and RS-422 communications in harsh environments.Each driver output and receiver input is protectedagainst ±15kV electro-static discharge (ESD) shocks,without latchup. These parts contain one driver and onereceiver. The MAX483E, MAX487E, MAX488E, andMAX489E feature reduced slew-rate drivers that minimizeEMI and reduce reflections caused by improperly terminatedcables, thus allowing error-free data transmissionup to 250kbps. The driver slew rates of the MAX481E,MAX485E, MAX490E, MAX491E, and MAX1487E are notlimited, allowing them to transmit up to 2.5Mbps.These transceivers draw as little as 120µA supply currentwhen unloaded or when fully loaded with disableddrivers (see Selector Guide). Additionally, the MAX481E,MAX483E, and MAX487E have a low-current shutdownmode in which they consume only 0.5µA. All parts operatefrom a single +5V supply.Drivers are short-circuit current limited, and are protectedagainst excessive power dissipation by thermal shutdowncircuitry that places their outputs into a high-impedancestate. The receiver input has a fail-safe feature that guaranteesa logic-high output if the input is open circuit.The MAX487E and MAX1487E feature quarter-unit-loadreceiver input impedance, allowing up to 128 transceiverson the bus. The MAX488E-MAX491E aredesigned for full-duplex communications, while theMAX481E, MAX483E, MAX485E, MAX487E, andMAX1487E are designed for half-duplex applications.For applications that are not ESD sensitive see the pinandfunction-compatible MAX481, MAX483, MAX485,MAX487-MAX491, and MAX1487.ApplicationsIndustrial-Control Local Area NetworksLevel TranslatorsLow-Power RS-422 TransceiversLow-Power RS-485 TransceiversTransceivers for EMI-Sensitive Applications

The MAX481E, MAX483E, MAX485E, MAX487E-MAX491E, and MAX1487E are low-power transceivers forRS-485 and RS-422 communications in harsh environments.Each driver output and receiver input is protectedagainst ±15kV electro-static discharge (ESD) shocks,without latchup. These parts contain one driver and onereceiver. The MAX483E, MAX487E, MAX488E, andMAX489E feature reduced slew-rate drivers that minimizeEMI and reduce reflections caused by improperly terminatedcables, thus allowing error-free data transmissionup to 250kbps. The driver slew rates of the MAX481E,MAX485E, MAX490E, MAX491E, and MAX1487E are notlimited, allowing them to transmit up to 2.5Mbps.These transceivers draw as little as 120µA supply currentwhen unloaded or when fully loaded with disableddrivers (see Selector Guide). Additionally, the MAX481E,MAX483E, and MAX487E have a low-current shutdownmode in which they consume only 0.5µA. All parts operatefrom a single +5V supply.Drivers are short-circuit current limited, and are protectedagainst excessive power dissipation by thermal shutdowncircuitry that places their outputs into a high-impedancestate. The receiver input has a fail-safe feature that guaranteesa logic-high output if the input is open circuit.The MAX487E and MAX1487E feature quarter-unit-loadreceiver input impedance, allowing up to 128 transceiverson the bus. The MAX488E-MAX491E aredesigned for full-duplex communications, while theMAX481E, MAX483E, MAX485E, MAX487E, andMAX1487E are designed for half-duplex applications.For applications that are not ESD sensitive see the pinandfunction-compatible MAX481, MAX483, MAX485,MAX487-MAX491, and MAX1487.ApplicationsIndustrial-Control Local Area NetworksLevel TranslatorsLow-Power RS-422 TransceiversLow-Power RS-485 TransceiversTransceivers for EMI-Sensitive Applications

The MAX481E, MAX483E, MAX485E, MAX487E-MAX491E, and MAX1487E are low-power transceivers forRS-485 and RS-422 communications in harsh environments.Each driver output and receiver input is protectedagainst ±15kV electro-static discharge (ESD) shocks,without latchup. These parts contain one driver and onereceiver. The MAX483E, MAX487E, MAX488E, andMAX489E feature reduced slew-rate drivers that minimizeEMI and reduce reflections caused by improperly terminatedcables, thus allowing error-free data transmissionup to 250kbps. The driver slew rates of the MAX481E,MAX485E, MAX490E, MAX491E, and MAX1487E are notlimited, allowing them to transmit up to 2.5Mbps.These transceivers draw as little as 120µA supply currentwhen unloaded or when fully loaded with disableddrivers (see Selector Guide). Additionally, the MAX481E,MAX483E, and MAX487E have a low-current shutdownmode in which they consume only 0.5µA. All parts operatefrom a single +5V supply.Drivers are short-circuit current limited, and are protectedagainst excessive power dissipation by thermal shutdowncircuitry that places their outputs into a high-impedancestate. The receiver input has a fail-safe feature that guaranteesa logic-high output if the input is open circuit.The MAX487E and MAX1487E feature quarter-unit-loadreceiver input impedance, allowing up to 128 transceiverson the bus. The MAX488E-MAX491E aredesigned for full-duplex communications, while theMAX481E, MAX483E, MAX485E, MAX487E, andMAX1487E are designed for half-duplex applications.For applications that are not ESD sensitive see the pinandfunction-compatible MAX481, MAX483, MAX485,MAX487-MAX491, and MAX1487.ApplicationsIndustrial-Control Local Area NetworksLevel TranslatorsLow-Power RS-422 TransceiversLow-Power RS-485 TransceiversTransceivers for EMI-Sensitive Applications

The MAX481E, MAX483E, MAX485E, MAX487E-MAX491E, and MAX1487E are low-power transceivers forRS-485 and RS-422 communications in harsh environments.Each driver output and receiver input is protectedagainst ±15kV electro-static discharge (ESD) shocks,without latchup. These parts contain one driver and onereceiver. The MAX483E, MAX487E, MAX488E, andMAX489E feature reduced slew-rate drivers that minimizeEMI and reduce reflections caused by improperly terminatedcables, thus allowing error-free data transmissionup to 250kbps. The driver slew rates of the MAX481E,MAX485E, MAX490E, MAX491E, and MAX1487E are notlimited, allowing them to transmit up to 2.5Mbps.These transceivers draw as little as 120µA supply currentwhen unloaded or when fully loaded with disableddrivers (see Selector Guide). Additionally, the MAX481E,MAX483E, and MAX487E have a low-current shutdownmode in which they consume only 0.5µA. All parts operatefrom a single +5V supply.Drivers are short-circuit current limited, and are protectedagainst excessive power dissipation by thermal shutdowncircuitry that places their outputs into a high-impedancestate. The receiver input has a fail-safe feature that guaranteesa logic-high output if the input is open circuit.The MAX487E and MAX1487E feature quarter-unit-loadreceiver input impedance, allowing up to 128 transceiverson the bus. The MAX488E-MAX491E aredesigned for full-duplex communications, while theMAX481E, MAX483E, MAX485E, MAX487E, andMAX1487E are designed for half-duplex applications.For applications that are not ESD sensitive see the pinandfunction-compatible MAX481, MAX483, MAX485,MAX487-MAX491, and MAX1487.ApplicationsIndustrial-Control Local Area NetworksLevel TranslatorsLow-Power RS-422 TransceiversLow-Power RS-485 TransceiversTransceivers for EMI-Sensitive Applications