MAX218 19-0246 Rev 1 7/95 1.8V to 4.25V-Powered, True RS-232 Dual Transceiver General Description Features The MAX218 RS-232 transceiver is intended for battery- BETTER THAN BIPOLAR powered EIA/TIA-232E and V.28/V.24 communications Operates Directly from Two Alkaline, NiCd, interfaces that need two drivers and two receivers with or NiMH Cells minimum power consumption. It provides a wide +1.8V +1.8V to +4.25V Supply Voltage Range to +4.25V operating voltage range while maintaining true RS-232 and EIA/TIA-562 voltage levels. The 120kbps Data Rate MAX218 runs from two alkaline, NiCd, or NiMH cells Low-Cost Surface-Mount Components without any form of voltage regulator. Meets EIA/TIA-232E Specifications A shutdown mode reduces current consumption to 1A, extending battery life in portable systems. While 1A Low-Power Shutdown Mode shut down, all receivers can remain active or can be Both Receivers Active During Low-Power Shutdown disabled under logic control, permitting a system incor- Three-State Receiver Outputs porating the CMOS MAX218 to monitor external devices while in low-power shutdown mode. Flow-Through Pinout A guaranteed 120kbps data rate provides compatibility On-Board DC-DC Converters with popular software for communicating with personal 20-Pin SSOP, Wide SO, or DIP Packages computers. Three-state drivers are provided on all receiver outputs so that multiple receivers, generally of different interface standards, can be wire-ORed at the Ordering Information UART. The MAX218 is available in 20-pin DIP, SO, and SSOP packages. PART TEMP. RANGE PIN-PACKAGE MAX218CPP 0C to +70C 20 Plastic DIP Applications MAX218CWP 0C to +70C 20 Wide SO Battery-Powered Equipment MAX218CAP 0C to +70C 20 SSOP Computers MAX218C/D 0C to +70C Dice* Printers MAX218EPP -40C to +85C 20 Plastic DIP Peripherals MAX218EWP -40C to +85C 20 Wide SO Instruments MAX218EAP -40C to +85C 20 SSOP Modems *Contact factory for dice specifications. Typical Operating Circuit Pin Configuration TOP VIEW 1 19 LX GND 1 20 LX V+ 1.8V 6 15 TO V- V CC N.C. V+ 2 19 4.25V 18 C1+ SHDN 3 18 C1+ MAX218 3 16 EN 4 17 GND ON/OFF SHDN C1- GND MAX218 C1- 5 16 7 T1IN T1OUT 14 T1 V V- CC 6 15 T2IN T2OUT 8 13 T1IN T1OUT T2 7 14 9 R1OUT R1IN 12 T2IN 8 13 T2OUT R1 R1OUT 12 R1IN 9 10 R2OUT R2IN 11 R2 R2OUT R2IN 10 11 EN GND 4 5, 17, 20 ENABLE DIP/SO/SSOP Maxim Integrated Products 1 Call toll free 1-800-998-8800 for free samples or literature.1.8V to 4.25V-Powered, True RS-232 Dual Transceiver ABSOLUTE MAXIMUM RATINGS Supply Voltages Short-Circuit Duration, R OUT, T OUT to GND ....... Continuous V ....................................................................-0.3V to +4.6V Continuous Power Dissipation (T = +70C) CC A V+.......................................................... (V - 0.3V) to +7.5V Plastic DIP (derate 11.11mW/C above +70C) ..........889mW CC V- .......................................................................+0.3V to -7.4V Wide SO (derate 10.00mW/C above +70C)..............800mW V to V-..........................................................................+12V SSOP (derate 8.00mW/C above +70C) ...................640mW CC LX ................................................................-0.3V to (1V + V+) Operating Temperature Ranges Input Voltages MAX218C P..................................................... 0C to +70C T IN, EN, SHDN ................................................. -0.3V to +7V MAX218E P ................................................... -40C to +85C R IN .................................................................................25V Storage Temperature Range ........................... -65C to +150C Output Voltages Lead Temperature (soldering, 10sec) ........................... +300C T OUT.............................................................................15V) R OUT....................................................-0.3V to (V + 0.3V) CC 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. ELECTRICAL CHARACTERISTICS (Circuit of Figure 1, V = 1.8V to 4.25V, C1 = 0.47F, C2 = C3 = C4 = 1F, L1 = 15H, T = T to T , unless otherwise noted. CC A MIN MAX Typical values are at V = 3.0V, T = +25C.) CC A PARAMETER CONDITIONS MIN TYP MAX UNITS DC CHARACTERISTICS Operating Voltage Range 1.8 4.25 V Supply Current (Note 1) No load, V = EN = SHDN = 3.0V, T = +25C 1.9 3.0 mA CC A SHDN = EN = 0V, all R INs static 0.04 10 Shutdown Supply Current A SHDN = 0V, EN = V , all R INs static 0.04 10 CC LOGIC Input Logic Threshold Low T IN, EN, SHDN 0.33 x V V CC Input Logic Threshold High T IN, EN, SHDN 0.67 x V V CC Input Hysteresis T IN 0.1 V Input Leakage Current T IN, EN, SHDN = 0V or V 0.001 1 A CC Output Voltage Low R OUT, I = 1.0mA 0.4 V OUT Output Voltage High R OUT, I = -0.4mA V - 0.25 V - 0.08 V OUT CC CC Output Leakage Current R OUT, 0V R OUT V , EN = 0V 0.05 10 A CC EIA/TIA-232E RECEIVER INPUTS Input Voltage Range -25 +25 V V = 2.0V to 4.25V 0.4 CC Input Threshold Low V V = 1.8V to 4.25V 0.3 CC V = 1.8V to 4.25V 3.0 CC Input Threshold High V V = 1.8V to 3.6V 2.8 CC Input Hysteresis 0.7 V Input Resistance -15V < R IN < +15V 35 7 k EIA/TIA-232E TRANSMITTER OUTPUTS Output Voltage Swing All transmitter outputs loaded with 3k to ground 5 6 V Output Resistance V = 0V, -2V < T OUT < +2V 300 CC Output Short-Circuit Current 24 100 mA Note 1: Entire supply current for the circuit of Figure 1. 2 MAX218