® SP385E-1 True +3V or +5V RS-232 Line Driver/Receiver ■ Operates from 3.3V or 5V Power Supply ■ Meets True EIA/TIA-232-F Standards from a +3.0V to +5.5V Power Supply ■ Meets EIA-562 Specifications at VCC≥ 2.7V ■ Two Drivers and Receivers ■ Operates with 0.1µF Capacitors ■ High Data Rate — 120kbps Under Load ■ Low Power Shutdown ≤1µA ■ 3-State TTL/CMOS Receiver Outputs ■ Low Power CMOS — <1mA Operation ■ Improved ESD Specifications: +15kV Human Body Model +15kV IEC1000-4-2 Air Discharge +8kV IEC1000-4-2 Contact Discharge DESCRIPTION The Sipex SP385E-1 is an enhanced version of the Sipex SP200 family of RS232 line drivers/receivers. The SP385E-1 offers +3.3V operation for EIA-562 and EIA-232 applications. The SP385E-1 maintains the same performance features offered in its predecessors. The SP385E-1 is available in plastic SOIC or SSOP packages operating over the commercial and industrial temperature ranges. The SP385E-1 is pin compatible to the LTC1385 EIA-562 transceiver, except the drivers in the SP385E-1 can only be disabled with the ON/OFF pin. RS232 OUTPUTS Charge Pumps T1 T2 R1 TTL/CMOS INPUTS Rev. 07/26/02 RS232 INPUTS R2 TTL/CMOS OUTPUTS SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 1 © Copyright 2001 Sipex Corporation Output Voltages TOUT .................................................................................................... (V+, +0.3V) to (V-, -0.3V) ROUT ................................................................................................................ -0.3V to (Vcc +0.3V) Short Circuit Duration TOUT ......................................................................................................................................... Continuous Power Dissipation CERDIP .............................................................................. 675mW (derate 9.5mW/°C above +70°C) Plastic DIP .......................................................................... 375mW (derate 7mW/°C above +70°C) Small Outline ...................................................................... 375mW (derate 7mW/°C above +70°C) ABSOLUTE MAXIMUM RATINGS This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. Vcc ................................................................................................................................................................. +6V V+ .................................................................................................................... (Vcc-0.3V) to +13.2V V- .............................................................................................................................................................. 13.2V Input Voltages TIN ......................................................................................................................... -0.3 to (Vcc +0.3V) RIN ............................................................................................................................................................ ±15V SPECIFICATIONS VCC = +3.3V ± 10%; cap on (V+) and (V-) = 1.0µF, C1 = C2 = 0.1µF; TMIN to TMAX unless otherwise noted. PARAMETERS TTL INPUT Logic Threshold Low High Logic Pullup Current Maximum Data Rate TTL OUTPUT TTL/CMOS Output Voltage, Low Voltage, High Leakage Current; TA = +25°C EIA-562 OUTPUT Output Voltage Swing Power-Off Output Resistance Output Short Circuit Current EIA-562 INPUT Voltage Range Voltage Threshold Low High Hysteresis Resistance DYNAMIC CHARACTERISTICS Driver Propagation Delay Receiver Propagation Delay Instantaneous Slew Rate MIN. TYP. MAX. 0.8 TIN ; ON/OFF Vcc = 3.3V TIN ; ON/OFF Vcc = 3.3V TIN = 0V CL = 2500pF, RL= 3kΩ Volts Volts µA IOUT = 1.6mA; Vcc = 3.3V IOUT = -1.0mA ON/OFF=0V, 0 ≤ VOUT ≤ VCC ±4.2 Volts ±35 Ω mA All transmitter outputs loaded with 3kΩ to ground VCC = 0V; VOUT = ±2V Infinite duration 0.01 200 120 0.4 VCC-0.6 0.05 ±10 300 -15 0.6 3 1.2 1.5 0.5 5 +15 Volts 2.4 1.0 7 Volts Volts Volts kΩ VCC = 3.3V, TA = +25°C VCC = 3.3V, TA = +25°C VCC = 3.3V, TA = +25°C VIN = 15V to –15V 30 µs µs V/µs TTL to RS-562 RS-562 to TTL CL = 10pF, RL= 3kΩ - 7kΩ; TA = +25°C CL = 2500pF, RL= 3kΩ; measured from +2V to -2V or -2V to +2V 1.0 0.3 Transition Region Slew Rate 10 V/µs Output Enable Time Output Disable Time POWER REQUIREMENTS VCC Power Supply Current 200 200 ns ns 0.5 6 8 Shutdown Supply Current Rev. 07/26/02 CONDITIONS Volts Volts µA kbps 2.0 ±3.7 UNITS mA mA 0.010 5 µA SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 2 No load, TA= +25°C; VCC = 3.3V All transmitters RL = 3kΩ TA = +25°C VCC = 3.3V, TA = +25°C © Copyright 2002 Sipex Corporation SPECIFICATIONS VCC = +3.3V ± 10%; cap on (V+) and (V-) = 1.0µF, C1 = C2 = 0.1µF; TMIN to TMAX unless otherwise noted. PARAMETERS TTL INPUT Logic Threshold Low High Logic Pullup Current Maximum Data Rate TTL OUTPUT TTL/CMOS Output Voltage, Low Voltage, High Leakage Current; TA = +25°C EIA-232 OUTPUT Output Voltage Swing MIN. TYP. MAX. UNITS Volts Volts µA kbps TIN ; ON/OFF TIN ; ON/OFF TIN = 0V CL = 2500pF, RL= 3kΩ Volts Volts µA IOUT = 1.6mA; Vcc = +5V IOUT = -1.0mA EN = VCC, 0V ≤ VOUT ≤ VCC ±9 Volts ±35 Ω mA All transmitter outputs loaded with 3kΩ to ground. VCC = 0V; VOUT = ±2V Infinite duration 0.8 2.4 0.01 200 120 0.4 VCC-0.6 0.05 ±5 Power-Off Output Resistance Output Short Circuit Current EIA-562 INPUT Voltage Range Voltage Threshold Low High Hysteresis Resistance DYNAMIC CHARACTERISTICS Propagation Delay, RS-232 to TTL Instantaneous Slew Rate ±10 300 -15 0.8 1.5 1.8 0.5 5 3 +15 Volts 2.4 1.0 7 Volts Volts Volts kΩ VCC = 5V, TA = +25°C VCC = 5V, TA = +25°C VCC = 5V, TA = +25°C VIN = 15V to –15V 30 µs V/µs TTL to RS-562 CL = 10pF, RL= 3kΩ - 7kΩ; TA =+25°C CL = 2500pF, RL= 3kΩ; measured from +3V to -3V or -3V to +3V 1 Transition Region Slew Rate 10 V/µs Output Enable Time Output Disable Time POWER REQUIREMENTS VCC Power Supply Current 200 200 ns ns 0.5 15 mA 25 Shutdown Supply Current CONDITIONS No load, TA= +25°C; VCC = 5V All transmitters RL = 3kΩ; TA = +25°C VCC = 5V, TA = +25°C mA 1 10 µA PERFORMANCE CURVES -11 12 30 10 25 8.4 8.2 -10 8.0 -6 VCC = 4V -5 0 2 4 6 8 10 Load Current (mA) Rev. 07/26/02 6 VCC = 4V VCC = 5V 15 4 10 2 5 0 0 -55 VCC = 4V 7.8 7.6 Load current = 0mA TA = 25°C 7.4 7.2 -4 -3 ICC (mA) VCC = 5V -7 20 VCC = 5V VOH (Volts) 8 -8 V+ (Volts) V– Voltage (Volts) -9 12 14 VCC = 3V 7.0 0 5 10 15 20 25 30 35 40 Load Current (mA) -40 0 25 70 85 Temperature (°C) SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 3 125 6.8 4.5 4.75 5.0 5.25 5.5 VCC (Volts) © Copyright 2001 Sipex Corporation PINOUT N/C 1 18 ON/OFF C1+ V+ 2 17 3 16 V CC GND C 1- 4 15 T1 OUT C2 + C2 - 5 14 R1 IN 6 13 R 1 OUT V- 7 12 T1 IN T2 OUT 8 11 R 2 IN 9 10 T2 IN R OUT 2 18-pin SOIC N/C 1 20 ON/OFF C 1+ 2 19 V CC GND V+ 3 18 C1 C2 + 4 17 5 16 C2 V- 6 15 7 14 T2OUT R2IN 8 13 9 12 N/C 10 11 T1 OUT R1 IN R1 OUT T IN 1 T IN 2 R OUT 2 N/C 20-pin SSOP TYPICAL OPERATING CIRCUIT +5V INPUT +5V INPUT 17 +10V to -10V Voltage Inverter V+ V- 0.1µF 16V 3+ + 7 2 0.1µF + 6.3V 4 5 + 0.1µF 16V 6 0.1µF 16V R1 OUT 13 2 8 T2 OUT 14 R 1 R1 IN 5kΩ R 2OUT 10 9 R 2 R2IN INPUTS T TTL/CMOS 11 OUTPUTS T IN 2 TTL/CMOS 400kΩ RS232 T1OUT OUTPUTS 1 15 RS232 T INPUTS TTL/CMOS INPUTS OUTPUTS TTL/CMOS 12 C + 19 Vcc +5V to +10V Voltage Doubler +10V to -10V Voltage Inverter T1 IN 14 V 3+ 7 + 0.1µF 16V T SP385E-1 1 17 T1 OUT 400kΩ T2 IN R 1OUT 13 15 T 2 8 16 R 1 T2 OUT R1IN 5kΩ R 2OUT 12 9 R 2 5kΩ R IN 2 5kΩ 18 SP385E-1 ON/OFF GND 16 GND SOIC Package Rev. 07/26/02 0.1µF 16V V 400kΩ 400kΩ T1 IN C + RS232 C + V +5V to +10V Voltage Doubler OUTPUTS C + + RS232 2 0.1µF + 6.3V 4 5 + 0.1µF 16V 6 0.1µF + INPUTS 0.1µF 20 ON/OFF 18 SSOP Package SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 4 © Copyright 2002 Sipex Corporation Driver/Transmitter The drivers are inverting level transmitters, that convert TTL or CMOS logic levels to ±5.0V EIA/TIA-232 levels inverted relative to the input logic levels. Typically the RS-232 output voltage swing is ±5.5V with no load and at least ±5V minimum fully loaded. The driver outputs are protected against infinite short-circuits to ground without degradation in reliability. Driver outputs will meet EIA/TIA-562 levels of ±3.7V with supply voltages as low as 2.7V. FEATURES… The Sipex SP385E-1 is a +3V to +5V EIA-232/ EIA-562 line transceiver. It is a pin-for-pin alternative for the SP310A and will operate in the same socket with 0.1µF capacitors, either polarized or non–polarized, in +3V supplies. The SP385E-1 offers the same features such as 120kbps guaranteed transmission rate, increased drive current for longer and more flexible cable configurations, low power dissipation and overall ruggedized construction for commercial and industrial environments. The SP385E-1 also includes a shutdown feature that tri-states the drivers and the receivers. The instantaneous slew rate of the transmitter output is internally limited to a maximum of 30V/µs in order to meet the standards [EIA 232D 2.1.7, Paragraph (5)]. However, the transition region slew rate of these enhanced products is typically 10V/µs. The smooth transition of the loaded output from VOL to VOH clearly meets the monotonicity requirements of the standard [EIA 232-D 2.1.7, Paragraphs (1) & (2)]. The SP385E-1 includes a charge pump voltage converter which allows it to operate from a single +3.3V or +5V supply. These converters double the VCC voltage input in order to generate the EIA-232 or EIA-562 output levels. For +5V operation, the SP385E-1 driver outputs adhere to all EIA-232-F and CCITT V.28 specifications. While at +3.3V operation, the outputs adhere to EIA-562 specifications. Due to Sipex's efficient charge pump design, the charge pump levels and the driver outputs are less noisy than other 3V EIA-232 transceivers. Receivers The receivers convert RS-232 input signals to inverted TTL signals. Since the input is usually from a transmission line, where long cable lengths and system interference can degrade the signal, the inputs have a typical hysteresis margin of 500mV. This ensures that the receiver is virtually immune to noisy transmission lines. The SP385E-1 has a single control line which simultaneously shuts down the internal DC/DC converter and puts all transmitter and receiver outputs into a high impedance state. The input thresholds are 0.8V minimum and 2.4V maximum, again well within the ±3V RS232 requirements. The receiver inputs are also protected against voltages up to ±15V. Should an input be left unconnected, a 5kΩ pull-down resistor to ground will commit the output of the receiver to a high state. The SP385E-1 is available in 18-pin plastic SOIC and 20-pin plastic SSOP packages for operation over commercial and industrial temperature ranges. Please consult the factory for surface-mount packaged parts supplied on tape-on-reel as well as parts screened to MILM-38510. In actual system applications, it is quite possible for signals to be applied to the receiver inputs before power is applied to the receiver circuitry. This occurs for example when a PC user attempts to print only to realize the printer wasn’t turned on. In this case an RS-232 signal from the PC will appear on the receiver input at the printer. When the printer power is turned on, the receiver will operate normally. All of these enhanced devices are fully protected. The SP385E-1 is ideal for +3.3V battery applications requiring low power operation. The charge pump strength allows the drivers to provide ±4.0V signals, plenty for typical EIA-562 applications since the EIA-562 receivers have input sensitivity levels of less than ±3V. THEORY OF OPERATION The SP385E-1 device is made up of three basic circuit blocks — 1) a driver/transmitter, 2) a receiver and 3) a charge pump. Rev. 07/26/02 SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 5 © Copyright 2001 Sipex Corporation the negative side of capacitor C2. Since C2+ is at +5V, the voltage potential across C2 is l0V. CHARGE PUMP The charge pump is a Sipex–patented design (5,306,954) and uses a unique approach compared to older less–efficient designs. The charge pump still requires four external capacitors, but uses a four–phase voltage shifting technique to attain symmetrical 10V power supplies. There is a free–running oscillator that controls the four phases of the voltage shifting. A description of each phase follows. Phase 4 — VDD transfer — The fourth phase of the clock connects the negative terminal of C2 to ground, and transfers the generated l0V across C2 to C4, the VDD storage capacitor. Again, simultaneously with this, the positive side of capacitor C1 is switched to +5V and the negative side is connected to ground, and the cycle begins again. Phase 1 — VSS charge storage —During this phase of the clock cycle, the positive side of capacitors C1 and C2 are initially charged to +5V. Cl+ is then switched to ground and the charge in C1– is transferred to C2–. Since C2+ is connected to +5V, the voltage potential across capacitor C2 is now 10V. Since both V+ and V– are separately generated from VCC; in a no–load condition V+ and V– will be symmetrical. Older charge pump approaches that generate V– from V+ will show a decrease in the magnitude of V– compared to V+ due to the inherent inefficiencies in the design. Phase 2 — VSS transfer — Phase two of the clock connects the negative terminal of C2 to the VSS storage capacitor and the positive terminal of C2 to ground, and transfers the generated –l0V to C3. Simultaneously, the positive side of capacitor C 1 is switched to +5V and the negative side is connected to ground. The clock rate for the charge pump typically operates at 15kHz. The external capacitors can be as low as 0.1µF with a 16V breakdown voltage rating. VCC = +5V C4 C1 Phase 3 — VDD charge storage — The third phase of the clock is identical to the first phase — the charge transferred in C1 produces –5V in the negative terminal of C1, which is applied to – – – – + VDD Storage Capacitor VSS Storage Capacitor C3 Figure 2. Charge Pump — Phase 2 C4 + –5V + + 10V +5V + – C2 –10V VCC = +5V C1 + C2 – + – –5V – + C2+ VDD Storage Capacitor VSS Storage Capacitor GND C3 GND C2- Figure 1. Charge Pump — Phase 1 -10V Figure 3. Charge Pump Waveforms Rev. 07/26/02 SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 6 © Copyright 2002 Sipex Corporation in MIL-STD-883, Method 3015.7 for ESD testing. The premise of this ESD test is to simulate the human body’s potential to store electro-static energy and discharge it to an integrated circuit. The simulation is performed by using a test model as shown in Figure 6. This method will test the IC’s capability to withstand an ESD transient during normal handling such as in manufacturing areas where the ICs tend to be handled frequently. VCC = +5V C4 +5V C1 + – C2 –5V + – – + + – VDD Storage Capacitor VSS Storage Capacitor C3 –5V Figure 4. Charge Pump — Phase 3 VCC = +5V C4 +10V C1 + – C2 + – – + + – The IEC-1000-4-2, formerly IEC801-2, is generally used for testing ESD on equipment and systems. For system manufacturers, they must guarantee a certain amount of ESD protection since the system itself is exposed to the outside environment and human presence. The premise with IEC1000-4-2 is that the system is required to withstand an amount of static electricity when ESD is applied to points and surfaces of the equipment that are accessible to personnel during normal usage. The transceiver IC receives most of the ESD current when the ESD source is applied to the connector pins. The test circuit for IEC10004-2 is shown on Figure 7. There are two methods within IEC1000-4-2, the Air Discharge method and the Contact Discharge method. VDD Storage Capacitor VSS Storage Capacitor C3 Figure 5. Charge Pump — Phase 4 Shutdown (ON/OFF) The SP385E-1 has a shut-down/standby mode to conserve power in battery-powered systems. To activate the shutdown mode, which stops the operation of the charge pump, a logic "0" is applied to the appropriate control line. The shutdown mode is controlled on the SP385E-1 by a logic "0" on the ON/ OFF control line (pin 18 for the SOIC and pin 20 for the SSOP packages); this puts the transmitter outputs in a tri-state mode. ESD Tolerance The SP385E-1 device incorporates ruggedized ESD cells on all driver output and receiver input pins. The ESD structure is improved over our previous family for more rugged applications and environments sensitive to electro-static discharges and associated transients. The improved ESD tolerance is at least ±15KV without damage nor latch-up. SW2 SW1 Device Under Test CSS DC Power Source Figure 6. ESD Test Circuit for Human Body Model Contact-Discharge Module There are different methods of ESD testing applied: a) MIL-STD-883, Method 3015.7 b) IEC1000-4-2 Air-Discharge c) IEC1000-4-2 Direct Contact RSS RC C DC Power Source RV SW2 SW1 The Human Body Model has been the generally accepted ESD testing method for semiconductors. This method is also specified Rev. 07/26/02 RSS RC C Device Under Test CSS RS and RV add up to 330Ω 330 for or IEC1000-4-2. Figure 7. ESD Test Circuit for IEC1000-4-2 SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 7 © Copyright 2001 Sipex Corporation the ESD arc. The discharge current rise time is constant since the energy is directly transferred without the air-gap arc. In situations such as hand held systems, the ESD charge can be directly discharged to the equipment from a person already holding the equipment. The current is transferred on to the keypad or the serial port of the equipment directly and then travels through the PCB and finally to the IC. 30A 15A 0A 0ns The circuit models in Figures 6 and 7 represent the typical ESD testing circuit used for all three methods. The CS is initially charged with the DC power supply when the first switch (SW1) is on. Now that the capacitor is charged, the second switch (SW2) is on while SW1 switches off. The voltage stored in the capacitor is then applied through RS, the current limiting resistor, onto the device under test (DUT). In ESD tests, the SW2 switch is pulsed so that the device under test receives a duration of voltage. 30ns Figure 8. ESD Test Waveform for IEC1000-4-2 With the Air Discharge Method, an ESD voltage is applied to the equipment under test (EUT) through air. This simulates an electrically charged person ready to connect a cable onto the rear of the system only to find an unpleasant zap just before the person touches the back panel. The high energy potential on the person discharges through an arcing path to the rear panel of the system before he or she even touches the system. This energy, whether discharged directly or through air, is predominantly a function of the discharge current rather than the discharge voltage. Variables with an air discharge such as approach speed of the object carrying the ESD potential to the system and humidity will tend to change the discharge current. For example, the rise time of the discharge current varies with the approach speed. For the Human Body Model, the current limiting resistor (RS) and the source capacitor (CS) are 1.5kΩ an 100pF, respectively. For IEC-1000-4-2, the current limiting resistor (RS) and the source capacitor (CS) are 330Ω an 150pF, respectively. The higher CS value and lower RS value in the IEC1000-4-2 model are more stringent than the Human Body Model. The larger storage capacitor injects a higher voltage to the test point when SW2 is switched on. The lower current limiting resistor increases the current charge onto the test point. The Contact Discharge Method applies the ESD current directly to the EUT. This method was devised to reduce the unpredictability of SP385E-1 Family Driver Outputs Receiver Inputs HUMAN BODY MODEL Air Discharge ±15kV ±15kV ±15kV ±15kV IEC1000-4-2 Direct Contact ±8kV ±8kV Level 4 4 Table 1. Transceiver ESD Tolerance Levels Rev. 07/26/02 SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 8 © Copyright 2002 Sipex Corporation PACKAGE: PLASTIC SMALL OUTLINE (SOIC) (WIDE) E H D A Ø e B A1 L DIMENSIONS (Inches) Minimum/Maximum (mm) Rev. 07/26/02 18–PIN A 0.090/0.104 (2.29/2.649)) A1 0.004/0.012 (0.102/0.300) B 0.013/0.020 (0.330/0.508) D 0.447/0.463 (11.35/11.74) E 0.291/0.299 (7.402/7.600) e 0.050 BSC (1.270 BSC) H 0.394/0.419 (10.00/10.64) L 0.016/0.050 (0.406/1.270) Ø 0°/8° (0°/8°) SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 9 © Copyright 2001 Sipex Corporation PACKAGE: PLASTIC SHRINK SMALL OUTLINE (SSOP) E H D A Ø e B A1 L DIMENSIONS (Inches) Minimum/Maximum (mm) Rev. 07/26/02 20–PIN A 0.068/0.078 (1.73/1.99) A1 0.002/0.008 (0.05/0.21) B 0.010/0.015 (0.25/0.38) D 0.278/0.289 (7.07/7.33) E 0.205/0.212 (5.20/5.38) e 0.0256 BSC (0.65 BSC) H 0.301/0.311 (7.65/7.90) L 0.022/0.037 (0.55/0.95) Ø 0°/8° (0°/8°) SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 10 © Copyright 2002 Sipex Corporation ORDERING INFORMATION Part Number Temperature Range Package SP385E-1CA ........................................... 0°C to +70°C .......................................... 20–pin SSOP SP385E-1EA .......................................... –40°C to +85°C ........................................ 20–pin SSOP SP385E-1CT ............................................ 0°C to +70°C ........................................... 18–pin SOIC SP385E-1ET .......................................... –40°C to +85°C ......................................... 18–pin SOIC CT and ET packages available Tape–on–Reel. Please consult the factory for pricing and availability for this option, and for parts screened to MIL–STD–883. Corporation SIGNAL PROCESSING EXCELLENCE Sipex Corporation Headquarters and Sales Office 22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: [email protected] Sales Office 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600 Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. Rev. 07/26/02 SP385E-1 True +3V to +5V RS-232 Line Driver/Receiver 11 © Copyright 2001 Sipex Corporation