SP3243E 3 Driver/5 Receiver Intelligent +3.0V to +5.5V RS-232 Transceivers FEATURES ■ Meets true EIA/TIA-232-F Standards from a +3.0V to +5.5V power supply ■ Interoperable with EIA/TIA-232 and adheres to EIA/TIA-562 down to a +2.7V power source ■ AUTO ON-LINE® circuitry automatically wakes up from a 1µA shutdown ■ Regulated Charge Pump Yields Stable RS-232 Outputs Regardless of VCC Variations ■ Enhanced ESD Specifications: +15kV Human Body Model +15kV IEC1000-4-2 Air Discharge +8kV IEC1000-4-2 Contact Discharge ■ 250 Kbps min. transmission rate (EB) ■ 1000 Kbps min. transmission rate (EU) ■ Ideal for High Speed RS-232 Applications C2+ 1 28 C1+ C2- 2 27 V+ V- 3 26 VCC R1IN 4 25 GND R2IN 5 24 C1- R3IN 6 R4IN 7 SP3243E 23 ONLINE 22 SHUTDOWN 21 STATUS R5IN 8 T1OUT 9 20 R2OUT T2OUT 10 19 R1OUT T3OUT 11 18 R2OUT T3IN 12 17 R3OUT T2IN 13 16 R4OUT T1IN 14 15 R5OUT Now Available in Lead Free Packaging DESCRIPTION The SP3243E products are 3 driver/5 receiver RS-232 transceiver solutions intended for portable or hand-held applications such as notebook and palmtop computers. The SP3243E includes one complementary receiver that remains alert to monitor an external device's Ring Indicate signal while the device is shutdown. The SP3243E and EB devices feature slew-rate limited outputs for reduced crosstalk and EMI. The "U" and "H" series are optimized for high speed with data rates up to 1Mbps, easily meeting the demands of high speed RS-232 applications. The SP3243E series uses an internal high-efficiency, charge-pump power supply that requires only 0.1µF capacitors in 3.3V operation. This charge pump and Exar's driver architecture allow the SP3243E series to deliver compliant RS-232 performance from a single power supply ranging from +3.0V to +5.5V. The AUTO ON-LINE® feature allows the device to automatically "wake-up" during a shutdown state when an RS-232 cable is connected and a connected peripheral is turned on. Otherwise, the device automatically shuts itself down drawing less than 1µA. SELECTION TABLE Device Power Supplies RS-232 Drivers RS-232 Receivers External Components Auto On-Line Circuitry TTL 3State # of Pins Data Rate ESD Rating SP3243E +3.0V to +5.5V 3 5 4 Capacitors Yes Yes 28 120 15kV SP3243EB +3.0V to +5.5V 3 5 4 Capacitors Yes Yes 28 250 15kV SP3243EH +3.0V to +5.5V 3 5 4 Capacitors Yes Yes 28 460 15kV SP3243EU +3.0V to +5.5V 3 5 4 Capacitors Yes Yes 28 1000 15kV Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP3243E_100_072309 ABSOLUTE MAXIMUM RATINGS These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability and cause permanent damage to the device. Power Dissipation per package VCC.......................................................-0.3V to +6.0V V+ (NOTE 1).......................................-0.3V to +7.0V V- (NOTE 1)........................................+0.3V to -7.0V V+ + |V-| (NOTE 1)...........................................+13V ICC (DC VCC or GND current).........................+100mA 28-pin SOIC (derate 12.7mW/oC above +70oC).........1000mW 28-pin SSOP (derate 11.2mW/oC above +70oC)..........900mW 28-pin TSSOP (derate 13.2mW/oC above +70oC)......1059mW 32-pin QFN (derate 29.4mW/oC above +70oC)...........2352mW Input Voltages TxIN, ONLINE,SHUTDOWN, .....-0.3V to Vcc +6.0V RxIN...................................................................+15V Output Voltages TxOUT.............................................................+13.2V RxOUT, STATUS.......................-0.3V to (VCC +0.3V) Short-Circuit Duration TxOUT....................................................Continuous Storage Temperature......................-65°C to +150°C NOTE 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V. ELECTRICAL CHARACTERISTICS Unless otherwise noted, the following specifications apply for VCC = +3.0V to +5.5V with TAMB = TMIN to TMAX, C1 - C4 = 0.1µF. Typical values apply at VCC = +3.3V or +5.0V and TAMB = 25°C. PARAMETER MIN. TYP. MAX. UNITS CONDITIONS Supply Current, AUTO ONLINE® 1.0 10 µA All RxIN open, ONLINE = GND, SHUTDOWN = VCC, VCC = 3.3V TAMB = 25oC, TxIN = GND or VCC Supply Current, Shutdown 1.0 10 µA SHUTDOWN = GND, VCC = 3.3V, TAMB = 25oC, TxIN = Vcc or GND Supply Current AUTO ON-LINE® Disabled 0.3 1.0 mA ONLINE = SHUTDOWN = Vcc, no load, VCC = 3.3V, TAMB = +25oC, TxIN = GND or VCC 0.8 V V DC CHARACTERISTICS LOGIC INPUTS AND RECEIVER OUTPUTS Input Logic Threshold LOW HIGH 2.4 VCC = =3.3V or =5.0V, TxIN ONLINE, SHUTDOWN Input Leakage Current +0.01 +1.0 µA TxIN, ONLINE, SHUTDOWN, TAMB = +25oC, VIN = 0V to VCC Output Leakage Current +0.05 +10 µA Receivers disabled, VOUT = 0V to VCC 0.4 Output Voltage LOW Output Voltage HIGH V IOUT = 1.6mA VCC -0.6 VCC -0.1 V IOUT = -1.0mA +5.0 +5.4 V All driver outputs loaded with 3KΩ to GND, TAMB = +25oC DRIVER OUTPUTS Output Voltage Swing Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP3243E_100_072309 ELECTRICAL CHARACTERISTICS Unless otherwise noted, the following specifications apply for VCC = +3.0V to +5.5V with TAMB = TMIN to TMAX, C1 - C4 = 0.1µF. Typical values apply at VCC = +3.3V or +5.0V and TAMB = 25°C. PARAMETER MIN. TYP. MAX. UNITS +35 +60 mA +25 µA 15 V CONDITIONS DRIVER OUTPUTS (continued) Output Resistance 300 Output Short-Circuit Current Ω Output Leakage Current VCC = V+ = V- = 0V, VOUT=+2V VOUT = 0V VCC = 0V or 3.0V to 5.5V, VOUT = +12V, Drivers disabled RECEIVER INPUTS Input Voltage Range -15 Input Threshold LOW 0.6 1.2 Input Threshold LOW 0.8 1.5 V Vcc = 3.3V V Vcc = 5.0V Input Threshold HIGH 1.5 2.4 V Vcc = 3.3V Input Threshold HIGH 1.8 2.4 V Vcc = 5.0V Input Hysteresis 0.3 Input Resistance 3 5 V 7 kΩ AUTO ON-LINE® CIRCUITRY CHARACTERISTICS (ONLINE = GND, SHUTDOWN = VCC) 25°C STATUS Output Voltage LOW STATUS Output Voltage HIGH 0.4 VCC -0.6 V IOUT = 1.6mA V IOUT = -1.0mA Receiver Threshold to Drivers Enabled (tONLINE) 350 µs Figure 14 Receiver Positive or Negative Threshold to STATUS HIGH (tSTSH) 0.2 µs Figure 14 Receiver Positive or Negative Threshold to STATUS LOW (tSTSL) 30 µs Figure 14 TIMING CHARACTERISTICS Maximum Data Rate (U) 1000 (H) 460 (B) 250 (-) 120 Kbps RL = 3KΩ, CL = 250pF, one driver active RL = 3KΩ, CL = 1000pF, one driver active RL = 3KΩ, CL = 1000pF, one driver active RL = 3KΩ, CL = 1000pF, one driver active Receiver Propagation Delay tPHL tPLH 0.15 0.15 µs Receiver input to Receiver output, CL = 150pF Receiver Output Enable Time 200 ns Normal operation Receiver Output Disable Time 200 ns Normal operation Driver Skew (E, EB) (EU) 100 50 ns | tPHL - tPLH | Receiver Skew 50 ns | tPHL - tPLH | Transition-Region Slew Rate (U) (EB) 6 90 500 100 30 V/µs Vcc = 3.3V, RL = 3kΩ, TAMB = 25°C, measurements taken from -3.0V to +3.0V or +3.0V to -3.0V Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP3243E_100_072309 TYPICAL PERFORMANCE CHARACTERISTICS Unless otherwise noted, the following performance characteristics apply for VCC = +3.3V, 1000kbps data rate, all drivers loaded with 3kΩ, 0.1µF charge pump capacitors, and TAMB = +25°C. 200 6 4 Transmitter Output Voltage (V) Skew (ns) 150 100 T1 at 500Kbps T2 at 31.2Kbps All TX loaded 3K // CLoad 50 0 250 500 1000 1500 Load Capacitance (pF) -4 2.7 3 3.5 4 Supply V oltage (V) 4.5 5 Figure 2. Transmitter Output Voltage VS. Supply Voltage for the SP3243EU 40 2Mbps 4 1.5Mbps 35 1Mbps Supply Current (mA) Transmitter Output V oltage (V) -2 2000 6 2 1 TX at full data rate 2 TX’s at1/16 data rate 0 -2 -4 1.5Mbps 2Mbps 0 250 1Mbps 500 1000 1500 Load Capacitance (pF) 2000 120Kbps 250Kbps 25 20Kbps 20 15 1 Transmi tter at full Data Rate 10 2 Transmi tters at 1 5.5 Kbps 5 All Transmi tters loa des 3K + Load Cap 0 1000 2000 3000 4000 5000 Load Capacitance (pF) Figure 4. Supply Current VS. Load Capacitance for the SP3243EU 6 25 4 Transmitter Output Voltage (V) 20 15 10 1 Transmitter at 250Kbps 2 Transmitters at 15.6Kbps All drivers loaded with 3K // 1000pF 5 0 30 0 Figure 3. Transmitter Output Voltage VS. Load Capacitance for the SP3243EU Supply Current (mA) 1Driver at 1Mbps Other Drivers at 62.5Kbps All Drive rs Loaded with 3K // 250pF 0 -6 0 Figure 1. Transmitter Skew VS. Load Capacitance -6 2 2.7 3 3.5 4 4.5 0 -2 Supply V oltage (V DC) TxOUT - -4 -6 5 TxOUT + 2 0 1000 2000 3000 4000 5000 Load Capacitance (pF) Figure 6. Transmitter Output Voltage VS. Load Capacitance for the SP3243EB Figure 5. Supply Current VS. Supply Voltage for the SP3243EU Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP3243E_100_072309 TYPICAL PERFORMANCE CHARACTERISTICS Unless otherwise noted, the following performance characteristics apply for VCC = +3.3V, 1000kbps data rate, all drivers loaded with 3kΩ, 0.1µF charge pump capacitors, and TAMB = +25°C. Slew Rate (V/µs) 25 20 - Slew + Slew 15 10 1 Transmitter at 250Kbps 2 Transmitter at 15.6Kbps 5 0 All drivers loaded 3K + Load Cap 0 500 1000 2000 3000 4000 5000 Load Capacitance (pF) Figure 7. Slew Rate VS. Load Capacitance Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP3243E_100_072309 PIN NUMBER NAME FUNCTION SP3243E SP3243EUCR QFN C1+ V+ Positive terminal of the voltage doubler charge-pump capacitor 28 28 Regulated +5.5V output generated by the charge pump 27 26 C1- Negative terminal of the voltage doubler charge-pump capacitor 24 22 C2+ Positive terminal of the inverting charge-pump capacitor 1 29 C2- Negative terminal of the inverting charge-pump capacitor 2 31 V- Regulated -5.5V output generated by the charge pump 3 32 R1IN RS-232 receiver input. 4 2 R2IN RS-232 receiver input 5 3 R3IN RS-232 receiver input 6 4 R4IN RS-232 receiver input 7 5 R5IN RS-232 receiver input 8 6 R1OUT TTL/CMOS receiver output 19 17 R2OUT TTL/CMOS receiver output 18 16 R2OUT Non-inverting receiver-2 output, active in shutdown 20 18 R3OUT TTL/CMOS receiver output 17 15 R4OUT TTL/CMOS receiver output 16 14 R5OUT TTL/CMOS receiver output 15 13 STATUS TTL/CMOS Output indicating online and shutdown status 21 19 T1IN TTL/CMOS driver input 14 12 T2IN TTL/CMOS driver input 13 11 T3IN TTL/CMOS driver input 12 10 ONLINE Apply logic HIGH to override AUTO ON-LINE® circuitry keeping drivers acive (SHUTDOWN must also be logic HIGH, refer to Table 2) 23 21 T1OUT RS-232 driver output 9 7 T2OUT RS-232 driver output 10 8 T3OUT RS-232 driver output 11 9 GND Ground 25 23 VCC +3.0V to +5.5V supply voltage 26 25 SHUTDOWN Apply logic LOW to SHUTDOWN driver and charge pump. This overrides all AUTO ON-LINE® circuitry and ONLINE (Refer to table 2) 22 20 NC No Connection - 1,24,27,30 Table 1. Device Pin Description Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP3243E_100_072309 VCC C5 C1 C2 + + + 26 0.1µ F VCC 28 C1+ 0.1µ F TTL/CMOS INPUTS 27 C3 24 C11 C2+ 0.1µ F V+ SP3243E V- + 0.1µ F 3 C4 2 C214 T1IN T1OUT 13 T2IN T2OUT 10 12 T3IN T3OUT 11 + 0.1µ F 9 RS-232 OUTPUTS 20 R2OUT 19 R1OUT 5kΩ 18 R2OUT TTL/CMOS OUTPUTS 5kΩ 17 R3OUT 5kΩ 16 R4OUT 5kΩ 15 R5OUT VCC 22 23 4 R2IN 5 R3IN 6 R4IN 7 R5IN 8 RS-232 INPUTS 5kΩ SHUTDOWN ONLINE 21 STATUS To µ P Supervisor Circuit R1IN GND 25 25 26 27 28 29 30 1 24 2 23 3 22 4 21 SP3243E 5 20 16 15 NC GND C1ONLINE SHUTDOWN STATUS R 2 OUT R1 OUT T3 OUT T3 IN T2 IN T1 IN R5OUT R4OUT R3OUT R 2OUT 14 17 13 18 8 12 7 11 19 9 6 10 NC R1 IN R2 IN R3 IN R4 IN R5 IN T1OUT T2OUT 31 32 VC2NC C2+ C1+ NC V+ VCC Figure 8. SP3243E Typical Operating Circuit Figure 9. SP3243E QFN Pinout Configuration Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP3243E_100_072309 DESCRIPTION In many portable or hand-held applications, an RS-232 cable can be disconnected or a connected peripheral can be turned off. Under these conditions, the internal charge pump and the drivers will be shut down. Otherwise, the system automatically comes online. This feature allows design engineers to address power saving concerns without major design changes. The SP3243E transceivers meet the EIA/TIA232 and ITU-T V.28/V.24 communication protocols and can be implemented in battery-powered, portable, or hand-held applications such as notebook or palmtop computers. The SP3243E devices feature Exar's proprietary and patented (U.S.‑‑ 5,306,954) on-board charge pump circuitry that generates ±5.5V RS-232 voltage levels from a single +3.0V to +5.5V power supply. The SP3243EU devices can operate at a data rate of 1000kbps fully loaded. THEORY OF OPERATION The SP3243E series is made up of four basic circuit blocks: 1. Drivers 2. Receivers 3. the Exar proprietary charge pump, and 4. AUTO ON-LINE® circuitry. The SP3243E is a 3-driver/5-receiver device, ideal for portable or hand-held applications. The SP3243E includes one complementary always-active receiver that can monitor an external device (such as a modem) in shutdown. This aids in protecting the UART or serial controller IC by preventing forward biasing of the protection diodes where VCC may be disconnected. Drivers The drivers are inverting level transmitters that convert TTL or CMOS logic levels to 5.0V EIA/ TIA-232 levels with an inverted sense relative to the input logic levels. Typically, the RS-232 output voltage swing is +5.4V with no load and +5V minimum fully loaded. The driver outputs are protected against infinite short-circuits to ground without degradation in reliability. These drivers comply with the EIA-TIA-232-F and all previous RS-232 versions. Unused drivers inputs should be connected to GND or VCC. The SP3243E series is an ideal choice for power sensitive designs. The SP3243E devices feature AUTO ON-LINE® circuitry which reduces the power supply drain to a 1µA supply current. VCC + C5 + C1 C2 + 26 VCC 0.1 µF 28 C1+ 0.1 µF C3 24 C11 C2+ 0.1 µF V+ 27 SP3243E V- + The drivers have a minimum data rate of 250kbps (EB) or 1000kbps (EU) fully loaded. 0.1 µF Figure 11 shows a loopback test circuit used to test the RS-232 Drivers. Figure 12 shows the test results where one driver was active at 1Mbps and all three drivers loaded with an RS-232 receiver in parallel with a 250pF capacitor. Figure 13 shows the test results of the loopback circuit with all drivers active at 250kbps with typical RS-232 loads in parallel with 1000pF capacitors. A superior RS-232 data transmission rate of 1Mbps makes the SP3243EU an ideal match for high speed LAN and personal computer peripheral applications. 3 C4 2 C2- TxD 14 T1 IN T1 OUT RTS 13 T2 IN T2 OUT 10 DTR 12 T3 IN T3 OUT 11 RxD 19 R1 OUT CTS 18 R2 OUT DSR 17 R3 OUT DCD 16 R4OUT RI 15 R5OUT + 0.1 µF 9 RS-232 OUTPUTS 20 R2 OUT UART or Serial µC VCC 22 23 21 R 1 IN 4 5KΩ 5KΩ 5KΩ 5KΩ R 2 IN 5 R 3 IN 6 R 4 IN 7 R 5 IN 8 RS-232 INPUTS 5KΩ SHUTDOWN ONLINE STATUS GND 25 RESET µP Supervisor IC VIN Figure 10. Interface Circuitry Controlled by Microprocessor Supervisory Circuit Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP3243E_100_072309 Device: SP3243E +3V to +5V C5 C1 C2 + 0.1 µF C1+ + + 0.1 µF TTL/CMOS INPUTS V+ C1C2+ 0.1 µF VCC SP3243 + 0.1 µF VC4 C2T1IN T1OUT TXIN TXOUT + 0.1 µF 5KΩ 5KΩ VCC 1000pF ONLINE STATUS RxOUT R2OUT 0 High-Z High-Z Active 1 Active Active Active The receivers convert +5.0V EIA/TIA-232 levels to TTL or CMOS logic output levels. Receivers are High-Z when the AUTO ON-LINE® circuitry is enabled or when in shutdown. The truth table logic of the SP3243 driver and receiver outputs can be found in Table 2. 1000pF SHUTDOWN To µP Supervisor Circuit TxOUT Receivers RXIN RXOUT SHUTDOWN Table 2. SHUTDOWN Truth Tables Note: In AUTO ON-LINE® Mode where ONLINE = GND and SHUTDOWN = VCC, the device will shut down if there is no activity present at the Receiver inputs. R1IN R1OUT TTL/CMOS OUTPUTS C3 GND 18 Figure 11. Loopback Test Circuit for RS-232 Driver Data Transmission Rates The SP3243E includes an additional non-inverting receiver with an output R2OUT. R2OUT is an extra output that remains active and monitors activity while the other receiver outputs are forced into high impedance. This allows a Ring Indicator (RI) signal from a peripheral to be monitored without forward biasing the TTL/CMOS inputs of the other devices connected to the receiver outputs. Since receiver 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 300mV. This ensures that the receiver is virtually immune to noisy transmission lines. Should an input be left unconnected, an internal 5KΩ pulldown resistor to ground will commit the output of the receiver to a HIGH state. Figure 12. Loopback Test results at 1Mbps Figure 13. Loopback Test results at 250Kbps Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com SP3243E_100_072309 Charge Pump The charge pump is a Exar–patented design (U.S. 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 5.5V power supplies. The internal power supply consists of a regulated dual charge pump that provides output voltages 5.5V regardless of the input voltage (VCC) over the +3.0V to +5.5V range. This is important to maintain compliant RS-232 levels regardless of power supply fluctuations. Phase 4 — VDD transfer — The fourth phase of the clock connects the negative terminal of C2 to GND, and transfers this positive generated voltage across C2 to C4, the VDD storage capacitor. This voltage is regulated to +5.5V. At this voltage, the internal oscillator is disabled. Simultaneous with the transfer of the voltage to C4, the positive side of capacitor C1 is switched to VCC and the negative side is connected to GND, allowing the charge pump cycle to begin again. The charge pump cycle will continue as long as the operational conditions for the internal oscillator are present. The charge pump operates in a discontinuous mode using an internal oscillator. If the output voltages are less than a magnitude of 5.5V, the charge pump is enabled. If the output voltages exceed a magnitude of 5.5V, the charge pump is disabled. This oscillator controls the four phases of the voltage shifting. A description of each phase follows. 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. The clock rate for the charge pump typically operates at greater than 250kHz. The external capacitors can be as low as 0.1µF with a 16V breakdown voltage rating. Phase 1 — VSS charge storage — During this phase of the clock cycle, the positive side of capacitors C1 and C2 are initially charged to VCC. Cl+ is then switched to GND and the charge in C1– is transferred to C2–. Since C2+ is connected to VCC, the voltage potential across capacitor C2 is now 2 times VCC. 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 GND. This transfers a negative generated voltage to C3. This generated voltage is regulated to a minimum voltage of -5.5V. Simultaneous with the transfer of the voltage to C3, the positive side of capacitor C1 is switched to VCC and the negative side is connected to GND. Phase 3 — VDD charge storage — The third phase of the clock is identical to the first phase — the charge transferred in C1 produces –VCC in the negative terminal of C1, which is applied to the negative side of capacitor C2. Since C2+ is at VCC, the voltage potential across C2 is 2 times VCC. Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 10 SP3243E_100_072309 Minimum recommended charge pump capacitor value Input Voltage Vcc Charge pump capacitor value for SP32XX 3.0V to 3.6V C1 - C4 = 0.1µF 4.5V to 5.5V C1 = 0.047µF, C2 - C4 = 0.33µF 3.0V to 5.5V C1 - C4 = 0.22µF The Exar-patented charge pumps are designed to operate reliably with a range of low cost capacitors. Either polarized or non polarized capacitors may be used. If polarized capacitors are used they should be oriented as shown in the Typical Operating Circuit. The V+ capacitor may be connected to either ground or Vcc (polarity reversed.) reduces ripple on the transmitter outputs and may slightly reduce power consumption. C2, C3, and C4 can be increased without changing C1’s value. For best charge pump efficiency locate the charge pump and bypass capacitors as close as possible to the IC. Surface mount capacitors are best for this purpose. Using capacitors with lower equivalent series resistance (ESR) and self-inductance, along with minimizing parasitic PCB trace inductance will optimize charge pump operation. Designers are also advised to consider that capacitor values may shift over time and operating temperature. The charge pump operates with 0.1µF capacitors for 3.3V operation. For other supply voltages, see the table for required capacitor values. Do not use values smaller than those listed. Increasing the capacitor values (e.g., by doubling in value) AUTO ONLINE CIRCUITRY The SP3243E devices have a patent pending AUTO ON-LINE® circuitry on board that saves power in applications such as laptop computers, palmtop (PDA) computers and other portable systems. When the external transmitters are disabled or the cable is disconnected, the receiver inputs will be pulled down by their internal 5kΩ resistors to ground. When this occurs over a period of time, the internal transmitters will be disabled and the device goes into a shutdown or standy mode. When ONLINE is HIGH, the AUTO ON-LINE® mode is disabled. The SP3243E devices incorporate an AUTO ON-LINE® circuit that automatically enables itself when the external transmitters are enabled and the cable is connected. Conversely, the AUTO ON-LINE® circuit also disables most of the internal circuitry when the device is not being used and goes into a standby mode where the device typically draws 1µA. This function is externally controlled by the ONLINE pin. When this pin is tied to a logic LOW, the AUTO ON-LINE® function is active. Once active, the device is enabled until there is no activity on the receiver inputs. The receiver input typically sees at least +3V, which are generated from the transmitters at the other end of the cable with a +5V minimum. The AUTO ON-LINE® circuit has two stages: 1) Inactive Detection 2) Accumulated Delay Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 11 SP3243E_100_072309 S H U T RECEIVER +2.7V 0V RS-232 INPUT VOLTAGES -2.7V D O W N VCC STATUS 0V tSTSL tSTSH tONLINE DRIVER RS-232 OUTPUT VOLTAGES +5V 0V -5V Figure 14. AUTO ON-LINE® Timing Waveforms The first stage, shown in Figure 21, detects an inactive input. A logic HIGH is asserted on RXINACT if the cable is disconnected or the external transmitters are disabled. Otherwise, RXINACT will be at a logic LOW. This circuit is duplicated for each of the other receivers. The STATUS pin outputs a logic LOW signal if the device is shutdown. This pin goes to a logic HIGH when the external transmitters are enabled and the cable is connected. When the SP3243E devices are shut down, the charge pumps are turned off. V+ charge pump output decays to VCC, the V- output decays to GND. The decay time will depend on the size of capacitors used for the charge pump. Once in shutdown, the time required to exit the shut down state and have valid V+ and V- levels is typically 200µs. The second stage of the AUTO ON-LINE® circuitry, shown in Figure 22, processes all the receiver's RXINACT signals with an accumulated delay that disables the device to a 1µA supply current. The STATUS pin goes to a logic LOW when the cable is disconnected, the external transmitters are disabled, or the SHUTDOWN pin is invoked. The typical accumulated delay is around 20µs. For easy programming, the STATUS can be used to indicate DSR or a Ring Indicator signal. Tying ONLINE and SHUTDOWN together will bypass the AUTO ON-LINE® circuitry so this connection acts like a shutdown input pin. When the SP3243E drivers or internal charge pump are disabled, the supply current is reduced to 1µA. This can commonly occur in hand-held or portable applications where the RS-232 cable is disconnected or the RS-232 drivers of the connected peripheral are turned off. The AUTO ON-LINE® mode can be disabled by the SHUTDOWN pin. If this pin is a logic LOW, the AUTO ON-LINE® function will not operate regardless of the logic state of the ONLINE pin. Table 3 summarizes the logic of the AUTO ONLINE® operating modes. The truth table logic of the SP3243E driver and receiver outputs can be found in Table 2. Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 12 SP3243E_100_072309 VCC = +5V C4 +5V C1 + + C2 – –5V – + – VDD Storage Capacitor – + VSS Storage Capacitor C3 –5V Figure 15. Charge Pump — Phase 1 VCC = +5V C4 + C1 C2 – + – + – – + VDD Storage Capacitor VSS Storage Capacitor C3 -5.5V Figure 16. Charge Pump — Phase 2 VCC = +5V C4 +5V C1 + – C2 –5V + + – – – VDD Storage Capacitor + VSS Storage Capacitor C3 –5V Figure 17. Charge Pump — Phase 3 VCC = +5V +5.5V C1 + – C2 C4 + – + – – + VDD Storage Capacitor VSS Storage Capacitor C3 Figure 18. Charge Pump — Phase 4 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 13 SP3243E_100_072309 The SP3243E driver outputs are able to maintain voltage under loading of up to 2.5mA per driver, ensuring sufficient output for mouse-driving applications. 4 8.6 4.93 2.67 1.82 1.57 1.38 1.23 1.12 1.02 0.939 -2 0.62 0 3.46 Vout+ Vout- 2 0.869 Transmitter Output Voltage [V] 6 -4 -6 VOUT + 0 0 Load Current Per Transmitter [mA] 1 VOUT - Figure 19. SP3243E Driver Output Voltages vs. Load Current per Transmitter VCC C5 C1 C2 + + + 26 VCC 0.1 µF 28 C1+ 0.1 µF 27 C3 24 C11 C2+ 0.1 µF V+ SP3243E + 0.1 µF V- 3 C4 2 C214 T1IN T1OUT 13 T2IN T2OUT 10 12 T3IN T3OUT 11 + 0.1 µF 9 20 R2OUT R1IN 4 19 R1OUT 5k Ω 18 R2OUT 5k Ω 17 R3OUT 5k Ω 16 R4OUT 5k Ω 15 R5OUT VCC 22 23 To µP Supervisor Circuit R2IN 5 R3IN 6 R4IN 7 R5IN DB-9 Connector 8 5k Ω SHUTDOWN ONLINE 21 STATUS 6 7 8 9 GND 25 DB-9 Connector Pins: 1. Received Line Signal Detector 2. Received Data 3. Transmitted Data 4. Data Terminal Ready 5. Signal Ground (Common) 6. 7. 8. 9. 1 2 3 4 5 DCE Ready Request to Send Clear to Send Ring Indicator Figure 20. Circuit for the connectivity of the SP3243E with a DB-9 connector Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 14 SP3243E_100_072309 RS-232 SIGNA L AT RECEIVER INPUT SHUTDOWN INPUT ONL INE INPUT STATUS OUTPUT TRA NSCEIVER STATUS YES HIGH LOW HIGH Normal Operation NO HIGH HIGH LOW Normal Operation NO HIGH LOW LOW Shutdown (A u t o -On l i n e) YES LOW HIGH / LOW HIGH Shutdown NO LOW HIGH / LOW LO W Shutdown (Auto-Online) Table 3. AUTO ON-LINE® Logic RXINACT Inactive Detection Block RS-232 Receiver Block RXIN RXOUT Figure 21. Stage I of AUTO ON-LINE® Circuitry Delay Stage Delay Stage Delay Stage Delay Stage Delay Stage STATUS R1INACT R2INACT R4INACT R3INACT R5INACT SHUTDOWN Figure 22. Stage II of AUTO ON-LINE® Circuitry Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 15 SP3243E_100_072309 ESD Tolerance current when the ESD source is applied to the connector pins. The test circuit for IEC1000-4-2 is shown on Figure 24. There are two methods within IEC1000-4-2, the Air Discharge method and the Contact Discharge method. The SP3243E series 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. 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. 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 The Human Body Model has been the generally accepted ESD testing method for semi-conductors. This method is also specified 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 23. 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. The Contact Discharge Method applies the ESD current directly to the EUT. This method was devised to reduce the unpredictability of 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. 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 IEC1000-42 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 RS RC SW1 DC Power Source SW2 CS Device Under Test Figure 23. ESD Test Circuit for Human Body Model Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 16 SP3243E_100_072309 Contact-Discharge Model RS RC RV SW1 SW2 Device Under Test CS DC Power Source R S and RV add up to 330Ω for IEC1000-4-2. Figure 24. ESD Test Circuit for IEC1000-4-2 I→ The circuit models in Figures 23 and 24 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. 30A 15A 0A 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. t = 0ns t→ t = 30ns Figure 25. ESD Test Waveform for IEC1000-4-2 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. Device PIN TESTED Driver Outputs Receiver Inputs Human Body MODEL Air Discharge +15kV +15kV +15kV +15kV IEC1000-4-2 Direct Contact Level +8kV +8kV 4 4 Table 4. Transceiver ESD Tolerance Levels Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 17 SP3243E_100_072309 PACKAGE: 28 PIN WSOIC Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 18 SP3243E_100_072309 PACKAGE: 32 PIN QFN Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 19 SP3243E_100_072309 ▲ ▲ PACKAGE: 28 PIN SSOP e Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 20 SP3243E_100_072309 PACKAGE: 28 PIN TSSOP Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 21 SP3243E_100_072309 PRODUCT NOMENCLATURE SP3243 E U EY L /TR Tape and Reel options “L” suffix indicates Lead Free packaging Package Type Part Number A= SSOP Y= TSSOP T= WSOIC R= QFN Temperature Range C= Commercial Range 0ºc to 70ºC E= Extended Range -40ºc to 85ºC Speed Indicator ESD Rating Blank= 120Kbps B= 250Kbps H= 460kbps U= 1Mbps E= 15kV HBM and IEC 1000-4 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 22 SP3243E_100_072309 ORDERING INFORMATION Part Number Data Rate (kbps) Temp. Range Package SP3243ECA-L 120 0C to +70C 28 Pin SSOP SP3243ECT-L 120 0C to +70C 28 Pin WSOIC SP3243ECY-L 120 0C to +70C 28 Pin TSSOP SP3243EEA-L 120 -40C to +85C 28 Pin SSOP SP3243EET-L 120 -40C to +85C 28 Pin WSOIC SP3243EEY-L 120 -40C to +85C 28 Pin TSSOP SP3243EBCA-L 250 0C to +70C 28 Pin SSOP SP3243EBCT-L 250 0C to +70C 28 Pin WSOIC SP3243EBCY-L 250 0C to +70C 28 Pin TSSOP SP3243EBER-L 250 0C to +70C 32 Pin QFN SP3243EBEA-L 250 -40C to +85C 28 Pin SSOP SP3243EBET-L 250 -40C to +85C 28 Pin WSOIC SP3243EBEY-L 250 -40C to +85C 28 Pin TSSOP SP3243EBER-L 250 -40C to +85C 32 Pin QFN SP3243EHCA-L 460 0C to +70C 28 Pin SSOP SP3243EHCT-L 460 0C to +70C 28 Pin WSOIC SP3243EHEA-L 460 -40C to +85C 28 Pin SSOP SP3243EHET-L 460 -40C to +85C 28 Pin WSOIC SP3243EUCA-L 1000 0C to +70C 28 Pin SSOP SP3243EUCT-L 1000 0C to +70C 28 Pin WSOIC SP3243EUCY-L 1000 0C to +70C 28 Pin TSSOP SP3243EUER-L 1000 0C to +70C 32 Pin QFN SP3243EUEA-L 1000 -40C to +85C 28 Pin SSOP SP3243EUET-L 1000 -40C to +85C 28 Pin WSOIC SP3243EUEY-L 1000 -40C to +85C 28 Pin TSSOP SP3243EUER-L 1000 -40C to +85C 32 Pin QFN For Tape and Reel option add "/TR", Example: SP3243ECA-L/TR. Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 23 SP3243E_100_072309 REVISION HISTORY DATE REVISION DESCRIPTION 02/05/06 -- 07/23/09 1.0.0 Legacy Sipex Datasheet Convert to Exar Format, Update ordering information and change revision to 1.0.0. Notice EXAR Corporation reserves the right to make changes to any products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no representation that the circuits are free of patent infringement. Charts and schedules contained herein are only for illustration purposes and may vary depending upon a user's specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, in writting, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized ; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. Copyright 2009 EXAR Corporation Datasheet July 2009 Send your Interface technical inquiry with technical details to: [email protected] Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 24 SP3243E_100_072309