MAX3225CTP+

Overview

The MAX3225CTP+ is a dual RS-232 transceiver manufactured by Analog Devices Inc./Maxim Integrated. It operates on a single +3.0V to +5.5V supply and achieves a typical supply current of 1µA through the AutoShutdown Plus feature. The device guarantees a data rate of 1Mbps, supporting high-speed applications like ISDN modem communication. It includes two drivers and two receivers for full-duplex operation. The component is housed in a 20-pin TQFN-EP package with an exposed pad and supports an operating temperature range from 0°C to +70°C.

Feature Summary

• AutoShutdown Plus technology automatically reduces power consumption when the interface is idle or disconnected.
• MegaBaud capability ensures reliable 1Mbps transmission speeds for demanding serial communication tasks.
• Integrated dual charge pump generates required RS-232 voltage levels using only four small capacitors.

Applications

• Notebook, subnotebook, and palmtop computers
• Cellular phones and handheld equipment
• Battery-powered peripherals and printers

Procurement Notes

Verify the specific suffix CTP+ corresponds to the 20-pin TQFN-EP package and commercial temperature range (0°C to +70°C). Confirm lead-free/RoHS compliance status as indicated by the plus sign. Ensure the source document matches the official Analog Devices datasheet for accurate pinout and electrical specifications before finalizing procurement.

Selection Notes

Select this model for applications requiring 1Mbps data rates and low-power standby modes. The TQFN-EP package is suitable for space-constrained designs. Verify that the system environment remains within the 0°C to +70°C operating range. Consider the MAX3225EUP+ if extended industrial temperature ranges are required instead.

Part Context

This component belongs to the MAX3224–MAX3227/MAX3244/MAX3245 family of 3V-powered RS-232 transceivers. The MAX3225 variant specifically distinguishes itself by offering 1Mbps data rates compared to the 250kbps limit of the MAX3224 and MAX3226 models. All devices in this series share the same core AutoShutdown Plus functionality and low-dropout transmitter architecture.

Replacement Considerations

Public confirmed substitute part numbers include MAX3225EUP+, MAX3225CPP+, and MAX3225CAP+. These alternatives offer identical functional specifications but differ in package type or operating temperature range. Verify package compatibility and thermal requirements before substitution.

FAQ

How does the AutoShutdown Plus feature reduce power consumption?

The device enters a low-power shutdown mode when the RS-232 cable is disconnected or all transmitter/receiver inputs remain inactive for more than 30 seconds, reducing supply current to 1µA. It wakes up upon sensing a valid transition at any input.

What is the function of the READY output pin?

The READY output asserts high when the internal charge pumps are regulating and the device has generated sufficient voltage levels to begin transmitting. It indicates that the transceiver is ready for normal operation.

What capacitor values are required for 3.3V operation?

For a 3.3V supply, the datasheet specifies using 0.1µF capacitors for C1, C2, C3, and C4. A 0.1µF bypass capacitor is also recommended for VCC decoupling.