EVALUATION KIT AVAILABLE 50V Isolated, 3.0V to 5.5V, 250kbps, MAX3250 2 Tx/2 Rx, RS-232 Transceiver General Description Benefits and Features The MAX3250 is a 3.0V to 5.5V powered, 50V isolated Isolation Breaks Ground Loops Due to High Common- EIA/TIA-232 and V.28/V.24 communications interface Mode Voltages While Maintaining Data Rate with high data-rate capabilities. The MAX3250 is a dual 50V Isolation die part that operates with up to 50V difference 250kbps Guaranteed Data Rate between the RS-232 side and the logic side (ISOCOM FAULT Output Signals Excessive Isolated-Side to GND). This makes the device ideal for operation in noisy conditions with high common-mode voltages. Voltage This feature prevents damage to the device if RS-232 Integration of Isolation and RS-232 Saves Space lines are inadvertently short-circuited to a +24V or 48V SSOP Package power bus. Shutdown Allows Multiple Interfaces (IrDA, RS-232, The MAX3250 is powered by a single 3V to 5.5V supply RS-485) to be Connected to the Same UART on the logic side. Power is transferred from the logic High-Impedance Transmitter and Receiver side to the isolated side by 100V external capacitors. Outputs in Shutdown The MAX3250 has two receivers (Rx) and two drivers 20A Supply Current in Shutdown (Tx) and is guaranteed to run at data rates of 250kbps Inductorless/Transformerless Design Simplifies EMI while maintaining RS-232 output levels. The trans- ceivers have a proprietary low-dropout transmitter out- Compliance put stage, delivering true RS-232 performance from a Low-Cost Replacement for Opto-Isolated 3V to 5.5V supply with a dual charge pump. The device Transceivers features a FAULT open-drain output to signal an exces- Meets EIA/TIA-232 Specifications Down to 3.0V sive isolated-side voltage condition on any of the RS- 232 inputs. This output can drive an alarm LED or can be monitored by the processor to prevent operation under these conditions. The receiver outputs are high impedance in shutdown, allowing multiple interfaces Pin Configuration (IrDA, RS-232, RS-485) to be connected to the same UART. TOP VIEW The MAX3250 is available in a space-saving 28-pin + SSOP package. C1- 1 28 V CC Applications R1OUT 2 27 C2- Industrial Control R2OUT 3 26 GND Programmable Logic Controller T1IN 4 25 FAULT Point-of-Sale Equipment T2IN 5 24 SHDN MAX3250 N.C. 6 23 N.C. PC-to-Router Connections N.C. 7 22 N.C. Diagnostic Ports C1+ 8 21 C2+ Telecom Equipment C3+ 9 20 ISOVCC V+ 10 19 R1IN Ordering Information C3- 11 18 R2IN PART TEMP RANGE PIN-PACKAGE C4+ 12 17 T1OUT MAX3250CAI+ 0C to +70C 28 SSOP C4- 13 16 T2OUT MAX3250EAI+ -40C to +85C 28 SSOP V- 14 15 ISOCOM +Denotes a lead(Pb)-free/RoHS-compliant package. SSOP Typical Operating Circuit appears at end of data sheet. 19-2443 Rev 4 2/1550V Isolated, 3.0V to 5.5V, 250kbps, MAX3250 2 Tx/2 Rx, RS-232 Transceiver Absolute Maximum Ratings (All voltages referenced to GND, unless otherwise noted.) C1+, C2+, C3+, C3-, C4+, C4- V ...........................................................................-0.3V to +6V to ISOCOM .....................................-0.3V to (ISOVCC + 0.3V) CC ISOCOM...............................................................................80V T OUT Current ..............30mA (continuous), 50mA (peak, 10s) ISOVCC to ISOCOM.................................................-0.3V to +6V R IN Current..................30mA (continuous), 50mA (peak, 10s) V+ to ISOCOM (Note 1)............................................-0.3V to +7V ISOCOM Current ...........30mA (continuous), 50mA (peak, 10s) V- to ISOCOM (Note 1)............................................+0.3V to -7V Short-Circuit Duration T OUT to ISOCOM .................Continuous V+ + V- (Note 1) ...................................................................13V Continuous Power Dissipation (T = +70C) A Input Voltages 28-Pin SSOP (derate 15mW/C above +70C) .......1201.2mW T IN, SHDN ...........................................................-0.3V to +6V Operating Temperature Ranges R IN to ISOCOM...............................................................25V MAX3250CAI .....................................................0C to +70C Output Voltages MAX3250EAI...................................................-40C to +85C T OUT to ISOCOM ........................................................13.2V Storage Temperature Range .............................-65C to +150C R OUT.....................................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C CC FAULT....................................................................-0.3V to +6V Soldering Temperature (reflow) .......................................+260C C1-, C2-......................................................-0.3V to (V + 0.3V) CC Note 1: V+ and V- can have a maximum magnitude of 7V, but their absolute difference cannot exceed 13V. 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 (V = 3.0V to 5.5V, see Typical Operating Circuit and Table 1 for capacitor values, ISOCOM = GND, T = T to T , unless oth- CC A MIN MAX erwise noted. Typical values are at V = 3.3V and T = +25C.) (Note 2) CC A PARAMETER CONDITIONS MIN TYP MAX UNITS DC CHARACTERISTICS Supply Current SHDN = V , no load 15 35 mA CC SHDN = GND, V = GND 20 45 ISOCOM Supply Current Shutdown A SHDN = GND, V = 50V 350 ISOCOM Maximum Ground Differential V - V 50 V GND ISOCOM Isolation Resistance Between GND and ISOCOM 60 k LOGIC INPUTS Input Logic Low T IN, SHDN 0.8 V V = 3.3V 2.0 CC Input Logic High T IN, SHDN V V = 5.0V 2.4 CC Transmitter Input Hysteresis 0.5 V Input Leakage Current T IN, SHDN -1 0.01 +1 A RECEIVER OUTPUTS Output Leakage Current SHDN = GND -10 0.05 +10 A Output-Voltage Low I = 1.6mA 0.4 V OUT Output-Voltage High I = -1.0mA V - 0.6 V - 0.1 V OUT CC CC FAULT OUTPUT Output-Voltage Low I = 5mA 0.4 V OUT (Open Drain) Output Leakage Current FAULT not asserted 1 A FAULT Trip Level V - V 55 V GND ISOCOM www.maximintegrated.com Maxim Integrated 2