SP3225EEA-L/TR

SP3224E-SP3227E 3.0V to 5.5V RS-232 Transceivers with Auto On-Line® Plus FEATURES ■ 15kV ESD protected RS-232 I/O pins ■ Auto On-line® Plus automatic power saving mode ■ Meets true EIA/TIA-232-F standards from +3.0V to +5.5V power supply. ■ Adheres to EIA/TIA-562 for interoperability with EIA/TIA-232 down to a +2.7V supply voltage ■ Regulated charge pump yields stable RS-232 outputs ■ Drop-in replacement to MAX3224, ICL3224, MAX3225, ICL3225, MAX3226, ICL3226, MAX3227 and ICL3227 ■ SP3224E and SP3226E reduced EMI with a slew rate controlled 250kbps data rate ■ SP3225E and SP3227E- high speed data rate of 1 Mbps. ■ Available in RoHS compliant, Lead Free Packaging C1+ 1 2 V+ 3 READY 20 SHUTDOWN 19 VCC 18 GND 17 SP3224E 16 5 SP3225E 15 C2- 6 14 V- 7 C1- 4 C2+ 8 R2 IN 9 R 2 OUT 10 T2 OUT T1OUT R1IN R1OUT ONLINE 13 T1IN 12 T2IN 11 STATUS Typical Applications ■ Diagnostic/Serial ports on embedded applications ■ Handheld Test Equipment ■ PC related Peripherals and Equipment ■ Battery Powered Equipment ■ Point-of-sale Equipment ■ Set-top Box DESCRIPTION The SP3224E/3225E are 2-driver/2-receiver devices and the SP3226E/SP3227E are 1driver/1-receiver devices. All are ideal for computer peripherals, point-of-sale equipment, consumer and embedded applications. These devices use 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 it to deliver compliant RS-232 performance from a single power supply ranging from +3.0V to +5.5V. At voltages between 2.7V and 3.0V the driver outputs are compliant with RS-562 and can interface to RS-232 over short cables. The Auto On-line® Plus feature allows the device to automatically “wake-up” during a shutdown state upon detecting activity and to enter a low power shutdown if idle. This power saving feature functions without system intervention or modifications to software or drivers. SElection TABLE All devices feature 3.0V to 5.5V power supply, 4 small charge pump capacitors, and 15kV ESD protection. Device Data Rate (bps) No. of Drivers/Receivers READY pin Low-Power Shutdown Package SP3224E 250k 2/2 Yes Auto On-Line® Plus 20 SSOP/TSSOP SP3225E 1M 2/2 Yes Auto On-Line® Plus 20 SSOP/TSSOP SP3226E 250k 1/1 Yes Auto On-Line® Plus 16 SSOP/TSSOP SP3227E 1M 1/1 Yes Auto On-Line® Plus 16 SSOP/TSSOP Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com  SP3224E,3225E,3226E,3227E_101_081711 ABSOLUTE MAXIMUM RATINGS Supply Voltage (Vcc).................................................-0.3V to + 6.0V V+ (Note 1)................................................................-0.3V to + 7.0V V- (Note 1).................................................................+0.3V to - 7.0V |V+| + |V-| .................................................................................+13V Input voltage at TTL input pins ............................-0.3V to Vcc+0.3V RxIN......................................................................................... ±16V Driver output (from Ground).................................................. ±13.2V RxOUT, STATUS..................................................-0.3V to Vcc+0.3V Short Circuit Duration, TxOUT to GND,. Continuous (One output at a time maximum) Storage Temperature...............................................-65°C to +150°C Operating Temperature SP322XECX...........................0°C to +70°C Operating Temperature SP322XEEX........................-40°C to +85°C Lead Temperature (soldering, 10s)....................................... +300°C Maximum junction temperature.....................................................150°C Thermal Derating, Junction to Ambient SSOP20..............................................................................θJA =83°C/W TSSOP20.......................................................................θJA =110.7°C/W SSOP16..............................................................................θJA =87°C/W TSSOP16.......................................................................θJA =100.4°C/W 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. Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V. ELECTRICAL SPECIFICATIONS Unless otherwise noted VCC = +3.0V to +5.5V, TAMB = TMIN to TMAX,. Typical values are at TAMB = +25°C. C1–C4 = 0.1μF tested at 3.3V ±10%. C1=0.047μF C2–C4 = 0.33μF tested at 5V ±10%. Parameters Symb Test Conditions Min. Typ. Max. Unit DC Characteristics Supply Current, Auto On-Line® Plus Icc3 Receivers idle, TxIN = Vcc or GND, ONLINE = GND, SHUTDOWN = Vcc Note 2 1 10 μA Supply Current, Shutdown Icc2 SHUTDOWN = GND 1 10 μA Supply Current, Active Icc1 ONLINE = SHUTDOWN = Vcc, No Load 1.5 3.0 mA Icc1 ONLINE = SHUTDOWN = Vcc=3.3V, No Load 0.7 2.0 mA Vih Vcc = 3.3V 2 Vih Vcc = 5.0V 2.4 0.8 V Supply Current, Active Driver Input and Logic Input Pins High Logic Input Voltage Low Vil Logic Threshold Vt 1.5 Iil 0.05 Vhys 100 Logic Input Leakage Current Logic Input Hysteresis ±1.0 μA mV Receiver Outputs and STATUS Output Receiver Output Voltage Low Vol Iout = -1.6mA Receiver Output Voltage High Voh Iout = 1mA 0.4 Vcc - 0.6 V V Note 2: Characterized, not 100% tested. Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com  SP3224E,3225E,3226E,3227E_101_081711 ELECTRICAL SPECIFICATIONS Unless otherwise noted VCC = +3.0V to +5.5V, TAMB = TMIN to TMAX,. Typical values are at TAMB = +25°C. C1–C4 = 0.1μF tested at 3.3V ±10%. C1=0.047μF C2–C4 = 0.33μF tested at 5V ±10%. Parameters Symb Test Conditions Min. Typ. ±5.0 ±6.0 Max. Driver Outputs Output Voltage Swing Vo Output load = 3kΩ to GND Output load = Open Circuit Short Circuit Current Vout = 0V Power-Off Impedance Vcc=V+ = V- = 0 transmitter outputs= ±2V Output Leakage Current Vcc = 0 or 3V to 3.3V, Vout = ±12V, Drivers disabled V ±15.0 ±60 300 10M mA Ω ±25 μA 15 V Receiver Inputs Input Voltage Range -15 Input Threshold Low Input Threshold High Vcc = 3.3V 0.6 1.2 Vcc = 5.0V 0.8 1.5 V Vcc = 3.3V 1.5 2.4 Vcc = 5.0V 1.8 2.4 Input Hysteresis 500 Input Resistance 3 5 V mV 7 kΩ ESD Protection ESD Protection for R_In, T_Out pins Human Body Model ±15 kV All Other Pins Human Body Model ±2 kV ® Auto On-line Plus (ONLINE = GND, SHUTDOWN = Vcc) Rx Input Threshold to STATUS output high ±2.7 Rx Input Threshold to STATUS output low Threshold to STATUS high Threshold to STATUS low ±0.3 tsth tstl Rx or Tx transition to drivers enabled tonline Note 3 Last Rx or Tx transition to drivers disabled toffline Note 2, 3 V 0.5 μs 30 μs 100 15 V 30 μs 60 sec Note 3: A transmitter/receiver edge is defined as a transition through input logic thresholds. Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com  SP3224E,3225E,3226E,3227E_101_081711 Timing Characteristics Unless otherwise noted Vcc = +3.0V to +5.5V, Tamb = Tmin to Tmax,. Typical values are at Tamb = +25°C. C1–C4 = 0.1μF tested at 3.3V ±10%. C1=0.047μF C2–C4 = 0.33μF tested at 5V ±10% Parameters Symbol Test Conditions Min. Typ. Max. Unit SP3224E and SP3226E Maximum Data Rate RL = 3kΩ, CL = 1000pF. One transmitter switching. Transition -Region Slew Rate Measurement taken from +3.0V to -3.0V or -3.0V to +3.0V, Tamb = 25°C RL = 3kΩ to 7kΩ, CL = 150pF to 1000pF Receiver Propagation Delay tRPHL , tRPLH Receiver Output Enable Time tRZH , tRZL Receiver Output Disable Time tRHZ , tRLZ Receiver Skew Parameters 250 kbps 4 30 V/μs R_IN to R_OUT, CL = 150pF 0.22 RL = 3kΩ, CL = 150pF 0.2 2 µs 0.2  2 µs |tPHL - tPLH| at 1.5V Symbol µs 200 Test Conditions Min. Typ. ns Max. Unit SP3225E and SP3227E Maximum Data Rate RL = 3kΩ, CL = 250pF. One transmitter Switching 1000 kbps RL = 3kΩ, CL = 1000pF. One transmitter Switching 500 kbps Measurement taken from +3.0V to -3.0V or -3.0V to +3.0V, Tamb=25°C Instantaneous Slew Rate RL = 3kΩ to 7kΩ, 24 150 V/μs CL = 150pF to 250pF Driver Skew Receiver Propagation Delay |tDPHL - tDPLH| tRPHL , tRPLH at zero crossing R_IN to R_OUT, CL = 150pF 75 ns 0.20 µs Receiver Output Enable Time tRZH , tRZL 0.3 2 µs Receiver Output Disable Time tRHZ , tRLZ 0.2  2 µs Receiver Skew |tPHL - tPLH| at 1.5V 80 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com  ns SP3224E,3225E,3226E,3227E_101_081711 TYPICAL PERFORMANCE CHARACTERISTICS:Curves 1.6 TxIn to RxOut Propagation Delay (us) TxIn to RxOut Propagation Delay (us) 2.5 2 1.5 1 0.5 0 1000 1.2 1 0.8 0.6 0.4 TxIn 0.2 to RxOut Propagation Delay (us) TxIn to RxOut Propagation Delay (us) 0 1.4 2000 3000 4000 0 0 5000 1000 2000 5000 45 Transmitter Output Slew Rate (V/us) 30 Transmitter Output Slew Rate (V/us) 4000 SP3225E/SP3227E Transmitter Input to Receiver Output Propagation Delay vs. Load Capacitance SP3224E/SP3226E Transmitter Input to Receiver Output Propagation Delay vs. Load Capacitance 25 20 SRneg 15 SRavg 10 SRpos 5 Transmitter Output Slew Rate (V/us) 1000 40 35 SRpos 30 SRavg 25 SRneg 20 15 10 5 Transmitter Output Slew Rate (V/us) 0 0 2000 3000 4000 0 5000 0 Load Capacitance (pF) 1000 2000 3000 4000 5000 Load Capacitance (pF) SP3225E/SP3227E Transmitter Output Slew Rate vs. Load Capacitance SP3224E/SP3226E Transmitter Output Slew Rate vs. Load Capacitance 6 6 V+ 4 Transmitter Output Voltage (V) Transmitter Output Voltage (V) 3000 Load Capacitance (pF) Load Capacitance (pF) 2 0 -2 V+ 4 2 0 -2 Trasmitter Output Voltage (V) -4 V- Transmitter Output Voltage (V) -4 V- -6 -6 0 1000 2000 3000 4000 5000 0 1000 2000 3000 4000 5000 Load Capacitance (pF) Load Capacitance (pF) SP3224E/SP3226E Transmitter Output Voltage vs. Load Capacitance SP3225E/SP3227E Transmitter Output Voltage Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com  SP3224E,3225E,3226E,3227E_101_081711 TYPICAL PERFORMANCE CHARACTERISTICS:Curves Transmitter Skew (ns) 250 200 SP3225, 1Mbps 150 SP3224, 250kbps 100 Transmitter Skew (ns) 50 0 0 500 1000 1500 2000 2500 3000 3500 Load Capacitance (pF) Driver Skew vs. Load Capacitance 30 Supply Current (mA) 25 SP3225, 1Mbps SP3227 20 15 SP3224, 250kbps SP3226 10 Supply Current (mA) 5 0 0 1000 2000 3000 4000 5000 Load Capacitance (pF) Supply Current vs. Load Capacitance Charge Pump Turn-on Time versus Temperature Charge Pump Turn-On Time (us) 85 80 75 70 65 60 Charge Pump Turn-on Time (us) 55 50 -55 -30 -5 20 45 70 95 Temperature (C) Charge Pump Turn-On Time vs. Temperature Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com  SP3224E,3225E,3226E,3227E_101_081711 TYPICAL PERFORMANCE CHARACTERISTICS: Scope Shots SP3224E/SP3226E Waveforms for 250kbps Clock Rate, RL=3kΩ, CL=1000pF SP3224E/SP3226E Charge Pump Into Shutdown SP3224E/SP3226E Waveforms for 250kbps Clock Rate, RL=3kΩ, CL=4700pF SP3224E/SP3226E Charge Pump Power On Time, Vcc=3.3V SP3224E/SP3226E Charge Pump Out of Shutdown SP3224E/SP3226E Charge Pump Waveforms for 250kbp Clock Rate All Charge Pump waveforms use charge pump capacitor values C1-C4 = 0.1µF Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com  SP3224E,3225E,3226E,3227E_101_081711 TYPICAL PERFORMANCE CHARACTERISTICS: Scope Shots SP3224E/SP3226E C2+ Charge Pump Waveforms, Vcc=3.3V, All Channels switching SP3225E/SP3227E Waveforms for 1Mbps Clock Rate, RL=3KΩ, CL=250pF SP3224E/SP3226E C2+ Charge Pump Waveforms, Vcc=5V, All Channels switching SP3225E/SP3227E Waveforms for 1Mbps Clock Rate, RL=3KΩ, CL=1000pF SP3225E/SP3227E Waveforms for 1Mbps Clock Rate, RL=3KΩ, CL=50pF SP3225E/SP3227E Charge Pump Out of Shutdown All Charge Pump waveforms use charge pump capacitor values C1-C4 = 0.1µF Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com  SP3224E,3225E,3226E,3227E_101_081711 TYPICAL PERFORMANCE CHARACTERISTICS SP3225E/SP3227E Charge Pump Into Shutdown SP3225E/SP3227E Charge Pump Waveforms, Vcc=3.3V, All Channel Switching SP3225E/SP3227E Charge Pump Power On Time, Vcc=3.3V SP3225E/SP3227E Charge Pump Waveforms, Vcc=5V, All Channel Switching SP3225E/SP3227E Charge Pump Waveforms for 1Mbps Clock Rate All Charge Pump waveforms use charge pump capacitor values C1-C4 = 0.1µF Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com  SP3224E,3225E,3226E,3227E_101_081711 CHARacterization CIRCUITS AND WAVEFORMS Generator (see note B) 50Ω 3V SHUTDOWN 0V tTHL CL (see note A) RL 3V Input RS-232 Output tTLH 3V -3V 3V -3V Output VOH VOL 6V SR= tTHL or tTLH TEST CIRCUIT VOLTAGE WAVEFORMS NOTES A. CL includes probe and jig capacitance B. The pulse generator has the following characteristics: PRR= 250kbit/s, Zo=50Ω, 50% duty cycle, t r ≤10ns, tf ≤10ns Figure 1. Driver Slew Rate Generator (see note B) Input RS-232 Output 50Ω 3V SHUTDOWN 1.5V 0V tDPLH tDPHL CL (see note A) RL 3V 1.5V Output 50% 50% VOH VOL Skew= ItDPHL- tDPLHI TEST CIRCUIT VOLTAGE WAVEFORMS NOTES A. CL includes probe and jig capacitance B. The pulse generator has the following characteristics: PRR= 250kbit/s, Zo=50Ω, 50% duty cycle, t r ≤10ns, t f ≤10ns Figure 2. Driver Propagation and Skew 3V or 0V ONLINE Generator (see note B) RS-232 Output 50Ω Input 3V 1.5V 1.5V tRPHL CL (see note A) 3V SHUTDOWN 0V tRPLH Output 50% 50% VOH VOL TEST CIRCUIT VOLTAGE WAVEFORMS Skew= ItRPHL- tRPLHI NOTES A. CL includes probe and jig capacitance B. The pulse generator has the following characteristics: PRR= 250kbit/s, Zo=50Ω, 50% duty cycle, t r ≤10ns, t f ≤10ns Figure 3. Receiver Propagation Delay and Skew 3V or 0V ONLINE VCC S1 GND 1.5V tPHZ (51 at GND) RL 1.5V 0V tPZH Output 3V or 0V VOH Output 0.3V CL (see note A) SHUTDOWN Generator (See Note B) 3V Input 50% tPZL (S1 at VCC) tPLZ (51 at VCC) 50Ω 0.3V Output 50% VOL TEST CIRCUIT VOLTAGE WAVEFORMS NOTES: A CL includes probe and jig capacitance B. The pulse generator has the folowing characteristics Zo=50Ω, 50% duty cycle, t r ≤10ns, t f ≤10ns C. tPLZ and tPHZ are the same as tdis D. tPZL and tPZH are the same as ten Figure 4. Receiver Enable and Disable Times Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 10 SP3224E,3225E,3226E,3227E_101_081711 THEORY OF OPERATION rates fully loaded with 3KΩ in parallel with 1000pF (SP3224E/SP3226E), or 3KΩ in parallel with 250pF (SP3225E/SP3227E) ensuring compatibility with PC-to-PC communication software. The slew rate of the driver output on the SP3224E/SP3226E is internally limited to a maximum of 30V/μs in order to meet the EIA standards (EIA RS-232D 2.1.7, Paragraph 5). The Slew Rate of SP3225E/SP3227E is not limited to enable higher speed data transfers. The transition of the loaded output from HIGH to LOW also meets the monotonic signal transition requirements of the standard. Description The SP3224E and SP3225E are 2-driver/ 2-receiver devices. The SP3226E and SP3227E are 1-driver/1-receiver devices. All are ideal for serial ports in embedded, consumer, portable, or handheld applications. The transceivers meet the EIA/TIA232 and ITU-T V.28/V.24 communication protocols for reliable serial communication. The devices feature Exar’s proprietary and patented (U.S. 5,306,954) on-board charge pump circuitry that generates ±5.5V RS232 voltage levels from a single +3.0V to +5.5V power supply. The SP3224E-SP3227E are ideal choices for power sensitive designs. With the Auto On-line® Plus enabled, the SP3224ESP3227E reduce supply current to 1µA whenever the transceivers are in idle. In shutdown, the internal charge pump and the drivers will shut down. This feature allows design engineers to address power saving concerns without major design changes. Receivers The receivers convert EIA/TIA-232 signal levels to TTL or CMOS logic output levels. Receivers remain active during device shutdown. 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 500mV. 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. Theory Of Operation The SP3224E-SP3227E are made up of four basic circuit blocks: 1. Drivers, 2. Receivers, 3. the Exar proprietary charge pump, and 4. Auto On-line® Plus circuitry. Charge Pump The charge pump is a Exar–patented design (US Patent #5,306,954) and uses a unique approach compared to older lessefficient 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. The charge pump operates in a discontinuous mode using an internal oscillator. If the output voltages are less than a magnitude 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-TIA232-F and all previous RS-232 versions. Unused driver inputs should be connected to GND or VCC. The drivers can guarantee output data Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 11 SP3224E,3225E,3226E,3227E_101_081711 THEORY OF OPERATION is identical to the first phase. The positive terminals of capacitors C1 and C2 are charged from Vcc with their negative terminals initially connected to ground. C1+ is then connected to ground and the stored charge from C1– is superimposed onto C2–. Since C2+ is still connected to Vcc the voltage potential across capacitor C2 is now 2 x Vcc. 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. Highly Efficient Charge Pump The charge pump is used to generate positive and negative signal voltages for the RS-232 drivers. This enables fully compliant RS-232 and V.28 signals from a single 3.0 or 5.5V power supply. Phase 4 Vdd transfer: The fourth phase connects the negative terminal of C2 to ground and the positive terminal of C2 to the Vdd storage capacitor. This transfers the doubled (V+) voltage onto C3. Meanwhile, capacitor C1 charged from Vcc to prepare it for its next phase. The charge pumps use four external capacitors to hold and transfer electrical charge. The Exar patented design (US Patent #5,306,954) uses a unique approach compared to older less efficient designs. The pumps use a four–phase voltage shifting technique to attain symmetrical V+ and Vpower supplies. An intelligent control oscillator regulates the operation of the charge pump to maintain the proper voltages at maximum efficiency. The Exar charge pump generates V+ and V– independently from Vcc. Hence in a noload condition V+ and V- will be symmetrical. Older charge pump approaches generate V+ and then use part of that stored charge to generate V-. Because of inherent losses the magnitude of V- will be smaller than V+ on these older designs. Phase 1 Vss charge store and double: The positive terminals of capacitors C1 and C2 are charged from Vcc with their negative terminals initially connected to ground. C1+ is then connected to ground and the stored charge from C1– is superimposed onto C2– . Since C2+ is still connected to Vcc the voltage potential across capacitor C2 is now 2 x Vcc. Under lightly loaded conditions the intelligent pump oscillator maximizes efficiency by running only as needed to maintain V+ and V–. Since interface transceivers often spend much of their time at idle this powerefficient innovation can greatly reduce total power consumption. This improvement is made possible by the independent phase sequence of the Exar charge pump design. Phase 2 Vss transfer and invert: Phase two connects the negative terminal of C2 to the Vss storage capacitor and the positive terminal of C2 to ground. This transfers the doubled and inverted (V–) voltage onto C4. Meanwhile, capacitor C1 charged from Vcc to prepare it for its next phase. The clock rate for the charge pump typically operates at greater than 70kHz allowing the pump to run efficiently with small 0.1μF capacitors. Efficient operation depends on rapidly charging and discharging C1 and C2, therefore capacitors should be mounted close to the IC and have low ESR (equivalent series resistance). Inexpensive surface mount ceramic capacitors (such as Phase 3 Vdd charge store and double: Phase three Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 12 SP3224E,3225E,3226E,3227E_101_081711 THEORY OF OPERATION The SP3224E-SP3227E devices have the advanced Auto On-Line® Plus feature RS-232 signals use both positive and negative voltages of greater than ±5V magnitude. Receivers have nominal 5kΩ impedance to ground. Even when idle, drivers will maintain output signal voltage creating a continuous current flow. In low power, battery operated devices this constant current drain can decrease battery life significantly. are widely used for power-supply decoupling) are ideal for use on the charge pump. The charge pumps are designed to be able to function properly with a wide range of capacitor styles and values. If polarized capacitors are used the positive and negative terminals should be connected as shown on the Typical Operating Circuit. Capacitance values may be increased if operating at higher Vcc or to provide greater stability as the capacitors age. + V CC - Phase 2 – Vss transfer from C2 to C4. Meanwhile C1 is charged to Vcc + + V CC - C Phases 1 and 3: Store/Double. Double charge from C1 onto C2. C2 is now charged to -2xVcc + 1 C e- + 2 V+ e- e- C 3 + C Vss 4 + C + 1 C + 2 ee- V+ C V- + Patented 5,306,954 3 C + V CC - 4 Phase 4 VDD transfer from C2 to C3. Meanwhile C1 is charged to Vcc V e+ C + 1 C e- DD + 2 e+ + V+ V- C 3 + C 4 Charge Pump Phases Minimum Recommended Charge Pump Capacitor Values 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 Charge Pump Capacitor Values Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 13 SP3224E,3225E,3226E,3227E_101_081711 THEORY OF OPERATION that saves power by turning off the charge pumps and driver outputs when the transceiver inputs are idle for more than 30 seconds. Auto On-line® Plus is equivalent to Maxim’s “Auto Shutdown Plus” feature. It differs from our existing Auto On-line® by relying on signal transitions rather than voltage levels to trigger shutdown and wakeup. Auto On-Line® Plus automatically puts the device into a standby mode where it draws only 1μA typical. When the device detects activity on either the receiver or driver inputs it will automatically awake and activate to allow serial communication. Both the wakeup and shutdown happen automati- logic LOW forces the device into shutdown state regardless of input activity or the status of the ONLINE pin. The STATUS output determines whether a valid RS-232 signal voltage is present on the inputs. The STATUS pin goes to a logic LOW when the receiver input signal levels collapse near reference ground. This may occur when the RS-232 cable is disconnected or the RS-232 drivers of the connected peripheral are turned off. STATUS may be used to indicate DTR or a Ring Indicator signal or to determine whether a live RS232 driver or cable is connected. By connecting the STATUS output to ONLINE input, the SP3224E-SP3227E will shut down when no valid signal level and no input transitions are detected, and wake up on a valid signal level or signal edge. If it detects no signal transitions with the past 30 Receiver 5kΩ +0.3V R_IN -0.3V 30µs timer STATUS T_IN EDGE DETECT R_IN EDGE DETECT INVALID ASSERTED IF ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR AT LEAST 30µS Figure 3a.STATUS Functional Diagram STATUS low -2.7V S 30s timer A Figure 3c. Auto On-line¨ Plus Logic SHUTDOWN 30µs timer AUTO ONLINE ONLINE +2.7V R_IN SHUTDOWN POWERDOWN ONLINE STATUS AUTO ONLIN E POWERDOWN IS ONLY A INTERNAL SIGNAL. IT CONTROLS THE OPERATIONAL STATUS TO THE TRANSMITTERS AND THE POWER SUPPLIES. INVALID DEASSERTED IF ALL RECEIVER INPUTS ARE BETWEEN +2.7V AND -2.7V FOR AT LEAST 30µS Figure 3b. STATUS Functional Diagram, STATUS high. Figure 3d. Powerdown Logic cally, without any user intervention, special drivers, or software modifications. seconds, the device will go into low power mode. By connecting the STATUS output to both the ONLINE input and SHUTDOWN input pins, the device enters into shutdown when not receiving a valid RS-232 signal voltage input. Wakeup and shutdown can be externally controlled by the ONLINE and SHUTDOWN pins. When ONLINE is driven to logic LOW, the Auto On-line® Plus function is active. Driving SHUTDOWN to When the SP3224E-SP3227E devices are Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 14 SP3224E,3225E,3226E,3227E_101_081711 THEORY OF OPERATION 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 shutdown state and have valid V+ and V- levels is typically 50μs. When the SP3224E-SP3227E drivers and internal charge pump are disabled, the supply current is reduced to 1μA. Auto On-Line (existing) Device enters low-power mode if receiver inputs see less than valid +/- 3V. STATUS (or INVALID) signal output indicates if valid signal voltage is at receivers. Auto On-Line Plus (new) Device enters low-power mode if driver inputs or receiver inputs see no transitions for 30 seconds. Return to full power mode upon any transition on any driver input or receiver input Shutdown occurs even if data cable is connected to an active driver, as long as all inputs remain unchanged STATUS (or INVALID) signal functions as before. Indicates if valid signal voltage is present. But has no effect on shutdown For SP3224E the EN input is replaced with a READY output. READY drives high when charge pump achieves greater than -4V Vss (V-). Indicates “ready to transmit.” Comparison of Auto On-line® Features Operating Mode ONLINE SHDN |Rin| > ±2.7V Idle Inputs (Rxin & Txin) Txout Rxout Forced Shutdown X 0 X X Hi-Z Active Forced On-Line 1 1 X X Active Active Auto On-Line Plus (Wake when active) 0 1 X Active Active Active Auto On Line Plus (Off-Line when idle) 0 1 X Idle > 30s Hi-Z Active Auto On-Line Plus (Wake on cable) STATUS 1 Yes X Active Active Auto On-Line Plus (Wake when active) STATUS 1 No Active Active Active Auto On-Line Plus (Off-Line when idle) STATUS 1 No Idle > 30s Hi-Z Active Auto On-Line (Wake on cable) STATUS STATUS Yes X Active Active Auto On-Line (Auto Shutoff) STATUS STATUS No X Hi-Z Active Auto On-line® Plus Truth Table Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 15 SP3224E,3225E,3226E,3227E_101_081711 THEORY OF OPERATION RECEIVER INPUTS INVALID } REGION TRANSMITTER INPUTS TRANSMITTER OUTPUTS STATUS Vcc t TSTL OUTPUT 0 OUTPUT Vcc t STH t OFFLINE t OFFLINE tONLINE tONLINE 0 V+ Vcc 0 V- Auto On-Line® Plus Timing Diagram tstl (=30µs typ.) tsth (=0.4µs typ.) toffline (=30s typ.) tonline (=100µs typ.) Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 16 SP3224E,3225E,3226E,3227E_101_081711 TYPICAL OPERATING CIRCUIT VCC C5 C1 + + 15 VCC 0.1µ F 2 C1+ 0.1µ F C2 0.1µ F LOGIC INPUTS + C3 4 C1- SP3224E SP3225E 5 C2+ + 3 V+ 7 V- C4 6 C213 T1IN T1OUT 17 12 T2IN T2OUT 8 R1IN 16 R2IN 9 15 R1OUT + 10 R2OUT 0.1µ F RS-232 OUTPUTS 5kΩ LOGIC OUTPUTS 0.1µ F RS-232 INPUTS 5kΩ 1 14 READY 11 STATUS ONLINE 20 SHUTDOWN VCC GND 18 VCC C5 C1 + + 2 C1+ 0.1µ F 4 C15 C2+ C2 + LOGIC INPUT LOGIC OUTPUT 15 VCC 0.1µ F 0.1µ F V+ 3 C3 SP3226E SP3227E V- C4 T1OUT 9 R1OUT R1IN 12 READY ONLINE STATUS SHUTDOWN + 0.1µ F 13 RS-232 OUTPUT 8 RS-232 INPUT 5kΩ 1 0.1µ F 7 6 C211 T1IN + 10 16 VCC GND 14 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 17 SP3224E,3225E,3226E,3227E_101_081711 PinoUT DIAGRAMs 20 SHUTDOWN 19 VCC 18 GND 1 C1+ 2 V+ 3 READY 17 T1OUT 4 SP3224E 16 R1IN C2+ 5 SP3225E 15 R1OUT C2- 6 14 ONLINE V- 7 C1- 13 T1IN 12 T2IN 11 STATUS 8 R2 IN 9 R 2 OUT 10 T2 OUT 16 SHUTDOWN 15 VCC 14 GND 1 C1+ 2 V+ 3 READY 4 SP3226E 13 T1OUT C2+ 5 SP3227E 12 ONLINE 11 T1IN C2- 6 10 STATUS V- 7 C1- R1 IN 9 R1OUT 8 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 18 SP3224E,3225E,3226E,3227E_101_081711 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 19 SP3224E,3225E,3226E,3227E_101_081711 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 20 SP3224E,3225E,3226E,3227E_101_081711 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 21 SP3224E,3225E,3226E,3227E_101_081711 Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 510-668-7017 • www.exar.com 22 SP3224E,3225E,3226E,3227E_101_081711 ORDERING INFORMATION Part number Temperature range Package Type SP3224ECA-L From 0°C to +70°C Lead Free 20 pin SSOP SP3224ECY-L From 0°C to +70°C Lead Free 20 pin TSSOP SP3224EEA-L From -40°C to +85°C Lead Free 20 pin SSOP SP3224EEY-L From -40°C to +85°C Lead Free 20 pin TSSOP SP3225ECA-L From 0°C to +70°C Lead Free 20 pin SSOP SP3225ECY-L From 0°C to +70°C Lead Free 20 pin TSSOP SP3225EEA-L From -40°C to +85°C Lead Free 20 pin SSOP SP3225EEY-L From -40°C to +85°C Lead Free 20 pin TSSOP SP3226ECA-L From 0°C to +70°C Lead Free 16 pin SSOP SP3226ECY-L From 0°C to +70°C Lead Free 16 PIN SSOP SP3226EEA-L From -40°C to +85°C Lead Free 16 pin SSOP SP3226EEY-L From -40°C to +85°C Lead Free 16 PIN TSSOP SP3227ECA-L From 0°C to +70°C Lead Free 16 PIN SSOP SP3227ECY-L From 0°C to +70°C Lead Free 16 PIN TSSOP SP3227EEA-L From -40°C to +85°C Lead Free 16 PIN SSOP SP3227EEY-L From -40°C to +85°C Lead Free 16 PIN TSSOP Available in Tape on Reel DATE REVISION DESCRIPTION 11-20-06 P Legacy Sipex Datasheet 12-14-09 1.0.0 Update to Exar Format. Change revision to 1.0.0. Change Supply Current Active over full Vcc range maximum from 2.0mA to 3.0mA. Change Supply Current Active at Vcc = 3.3V maximum from 1.0mA to 2.0mA. Change RX input voltage ABS Maximum Rating from +/-18V to +/-16V. 08-17-11 1.0.1 Correct type error on front page Features list. 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 2011 EXAR Corporation Datasheet August 2011 Send your serial transceiver technical inquiry with technical details to: serialtechsupport@exar.com 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 23 SP3224E,3225E,3226E,3227E_101_081711