MAX232CPE+

The MAX232CPE+ is one member of the MAX232 series.It has the following features including (1)for low-voltage, integrated ESD applications;(2)for low-cost applications.

The MAX232CPE+ family of line drivers/receivers is intended for all EIA/TIA-232E and V.28/V.24 communications interfaces, particularly applications where ±12V is not available.These parts are especially useful in battery-powered systems,since their low-power shutdown mode reduces power dissipation to less than 5W.The MAX232 use no external components and are recommended for applications where printed circuit board space is critical.Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

Input thresholds of MAX232CPE+ are both TTL and CMOS compatible.The inputs of unused drivers can be left unconnected since 400k input pull-up resistors to VCC are built in . The pull-up resistors force the outputs of unused drivers low because all drivers invert.The internal input pull-up resistors typically source 12A,except in shutdown mode where the pull-ups are disabled.Driver outputs turn off and enter a high-impedance state-where leakage current is typically microamperes (maximum 25A)-when in shutdown mode, in three-state mode, or when device power is removed. Outputs can be driven to ±15V. The powersupply current typically drops to 8A in shutdown mode.The MAX232 have two internal charge-pumps that convert +5V to ±10V (unloaded) for RS-232 driver operation. The first converter uses capacitor C1 to double the +5V input to +10V on C3 at the V+ output. The second converter uses capacitor C2 to invert +10V to -10V on C4 at the V- output.The receivers have three modes of operation: full-speed receive (normal active)‚ three-state (disabled)‚ and lowpower receive (enabled receivers continue to function at lower data rates). The receiver enable inputs control the full-speed receive and three-state modes. The transmitters have two modes of operation: full-speed transmit (normal active) and three-state (disabled).The MAX232CPE+ transmitter enable inputs also control the shutdown mode. The device enters shutdown mode when all transmitters are disabled. Enabled receivers function in the low-power receive mode when in shutdown.