LMS202 5V Single Supply TIA/EIA-232 Dual Transceivers General Description Features The LMS202 features two transmitters and two receivers for RS-232 communication. It has a DC-to-DC converter that permits the device to operate with only a single +5V power supply. The on-chip DC-to-DC converter which utilizes four external 0.1µF capacitors to generate dual internal power supplies for RS-232 compatible output levels. n n n n n The device meet EIA/TIA-232E and CCITT V.28 specifications up to 230kbits/sec. The LMS202 is available in a 16 pin narrow and Wide SOIC package. Applications Single +5V power supply 230 kbps data rate On-board DC-to-DC converter 0.1µF charge pump capacitors Drop-in replacement to Maxim’s MAX202 n POS equipment (Bar code reader) n Hand-held equipment n General purpose RS-232 communication Connection Diagram and Typical Circuit 20062901 © 2003 National Semiconductor Corporation DS200629 www.national.com LMS202 5V Single Supply TIA/EIA-232 Dual Transceivers March 2003 LMS202 Pin Descriptions Pin Number Pin Name Pin Function 1, 3 C1+, C1− External capacitor connection pins. Recommended external capacitor C1 = 0.1µF (6.3V) 2 V+ Positive supply for TIA/EIA-232E drivers. Recommended external capacitor C4 = 0.1µF (6.3V) 4, 5 C2+, C2− External capacitor connection pins. Recommended external capacitor C2 = 0.1µF (16V) 6 V− Negative supply for TIA/EIA-232E drivers. Recommended external capacitor C3 = 0.1µF (16V) 7, 14 T1out, T2out Transmitter output pins conform to TIA/EIA-232E levels. The typical transmitter output swing is ± 8V when loaded 3kΩ load to ground. The open-circuit output voltage swings from (V+ − 0.6V) to V− 8,13 R1in, R2in Receiver inputs accept TIA/EIA-232 9, 12 R1out and R2out Receiver output pins are TTL/CMOS compatible 10, 11 Tin1, Tin2 Transmitter input pins are TTL/CMOS compatible. Inputs of transmitter do not have pull-up resistors. Connect all unused transmitter inputs to ground 15 GND Ground pin 16 VS Power supply pin for the device, +5V ( ± 10%) Ordering Information Package Part Number LMS202CM 16-Pin SOIC LMS202CMX LMS202IM LMS202IMX LMS202CMW 16-Pin Wide SOIC LMS202CMWX LMS202IMW LMS202IMWX www.national.com Package Marking LMS202CM LMS202IM LMS202CMW LMS202IMW 2 Transport Media NSC Drawing 48 Units/Rail 2.5k Units Tape and Reel 48 Units/Rail M16A 2.5k Units Tape and Reel 45 Units/Rail 1.0k Units Tape and Reel 45 Units/Rail 1.0k Units Tape and Reel M16B Infrared or Convection (Note 1) (20sec.) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VS −0.3V to 6V V+ (VS − 0.3V) to + 14V V− +0.3V to −14V Driver Input Voltage, TIN Driver Output Voltage TO Junction Temperature Supply Voltage VS Commercial (C) −40˚C to +85˚C Package Thermal Resistance (Note 3) Continuous ESD Rating 2kV Machine Model (Note 6) 0˚C to +70˚C Industrial (I) −0.3 to (VS + 0.3) Human Body Model (Note 2) 4.5V to 5.5V Ambient Temperature Range, TA ± 30V Short Circuit Duration, TO −65˚C to +150˚C Operating Ratings (V− −0.3V to (V+ + 0.3V) Receiver Output Voltage RO 150˚C Storage Temperature Range −0.3V to (V+ +0.3V) Receiver Input Voltage, RIN 235˚C 200V SO 71˚C/W WSO 55˚C/W Soldering Information Electrical Characteristics Over recommended operating supply and temperature ranges unless otherwise specified C1 = C2 = C3 = C4 = Cbp = 0.1µF Symbol Parameter Conditions Min (Note 5) Typ Max (Note 5) Units 1 7 mA µA DC Characteristics IS Supply Current No Load, TA = 25˚C IINPUT Input Leakage Current TIN = 0V to VS ± 10 VTHL Input Logic Theshold Low TIN 0.8 VTHH Input Logic Theshold High TIN VOL TTL/CMOS Output Voltage Low ROUT, IOUT = 3.2mA VOH TTL/CMOS Output Voltage High ROUT, IOUT = −1.0mA Logic 2.0 0.4 3.5 V V VS −0.1 V V RS-232 Receiver Inputs VRI Receiver Input Voltage Range VRTHL Receiver Input Theshold Low VS = 5V, TA = 25˚C VRTHH Receiver Input Theshold High VS = 5V, TA = 25˚C VHYST Receiver Input Hysteresis VS = 5V RI Receiver Input Resistance VS = 5V, TA = 25˚C −30 0.8 +30 1.4 V V 2 2.4 V 0.2 0.6 1.0 V 3 5 7 kΩ ±8 RS-232 Transmitter Outputs VO Transmitter Output Voltage Swing All transmitters loaded with 3kΩ to GND ±5 RO Output Resistance VS = V+ = V− = 0V, VO = ± 2V 300 IOS Output Short Circuit Current V Ω ± 11 ± 60 mA Timing Characteristics DR Maximum Data Rate CL = 50pF to 1000pF, RL = 3kΩ to 7kΩ TRPLH TRPHL Receiver Propagation Delay CL = 150pF 0.08 TDPLH TDPHL Transmitter Propagation Delay 2.4 RL = 3kΩ, CL = 2500pF All transmitters loaded 3 230 kbps 1 µs µs www.national.com LMS202 Absolute Maximum Ratings LMS202 Electrical Characteristics (Continued) Over recommended operating supply and temperature ranges unless otherwise specified C1 = C2 = C3 = C4 = Cbp = 0.1µF Symbol VSLEW Parameter Conditions Transition Region Slew Rate TA = 25˚C, VS = 5V CL = 50pF to 1000pF, RL = 3kΩ to 7kΩ Measured from +3V to −3V or vice versa Min (Note 5) Typ Max (Note 5) Units 3 6 30 V/µs Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics. Note 2: Human Body Model, 1.5kΩ in series with 100pF Note 3: The maximum power dissipation is a function of TJ(MAX), θJA, and TA. The maximum allowable power dissipation at any ambient temperature is PD = (TJ(MAX) − TA)/ θJA. All numbers apply for packages soldered directly onto a PC board. Note 4: Typical Values represent the most likely parametric norm. Note 5: All limits are guaranteed by testing or statistical analysis Note 6: Machine model, 0Ω in series with 200pF Typical Characteristics Transmitter Output High Voltage vs. Load Capacitance Transmitter Slew Rate vs. Load Capacitance 20062902 20062903 CHARGED PUMP The dual internal charged-pump provides the ± 10V to the to transmitters. Using capacitor C1, the charge pump converts +5V to +10V then stores the +10V in capacitor C3. The charge pump uses capacitor C2 to invert the +10V to −10V. The −10V is then stored in capacitor C4. Application Information CAPACITOR SELECTION The recommended capacitors are 0.1µF. However, larger capacitors for the charge pump may be used to minimized ripples on V+ and V− pins. POWER SUPPLY DECOUPLING In some applications that are sensitive to power supply noise from the charge pump, place a decoupling capacitor, Cbp, from VS to GND. Use at least a 0.1µF capacitor or the same size as the charge pump capacitors (C1 − C4). www.national.com 4 LMS202 Physical Dimensions inches (millimeters) unless otherwise noted 16-Pin SOIC NS Package Number M16A 16-Pin Wide SOIC NS Package Number M16B 5 www.national.com