19-1616; Rev 0; 1/00 ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers ____________________________Features ♦ ESD Protection for RS-232 I/O Pins ±15kV—Human Body Model ±8kV—IEC 1000-4-2, Contact Discharge ±15kV—IEC 1000-4-2, Air-Gap Discharge All devices are guaranteed at a data rate of 460kbps. The transceivers have a proprietary low-dropout transmitter output stage enabling RS-232 compatible operation from a +2.25V to +3.0V supply with a dual charge pump. The charge pump requires only four 0.1µF capacitors. The MAX3318E/MAX3319E feature a logiclevel output (READY) that asserts when the charge pump is regulating and the device is ready to begin transmitting. The MAX3318E/MAX3319E achieve a 1µA supply current using Maxim’s revolutionary AutoShutdown Plus feature. These devices automatically enter a low-power shutdown mode when the RS-232 cable is disconnected or the transmitters of the connected peripherals are inactive for more than 30 seconds. They turn on again when they sense a valid transition at any transmitter or receiver input. AutoShutdown Plus saves power without changes to the existing BIOS or operating system. The MAX3317E also features a 1µA shutdown mode that can be entered by driving SHDN low. The MAX3317E’s receivers remain active while in shutdown mode, allowing external devices such as modems to be monitored using only 1µA supply current. ♦ Guaranteed 4V/µs Slew Rate These devices are available in space-saving packages: MAX3316E (16-pin SSOP and 20-pin TSSOP), MAX3317E/ MAX3318E (20-pin SSOP and 20-pin TSSOP), and MAX3319E (16-pin SSOP). ________________________Applications Palmtop Computers Hand-Held Instruments ♦ 300µA Operating Supply Current ♦ 1µA Low-Power Shutdown with Receivers Active ♦ Guaranteed 460kbps Data Rate ♦ RS-232 Compatible Down to 2.25V Ordering Information PART TEMP. RANGE 0°C to +70°C 20 TSSOP MAX3316ECAE 0°C to +70°C 16 SSOP MAX3316EEUP -40°C to +85°C MAX3316EEAE -40°C to +85°C MAX3317ECUP GPS Handy Terminals Hand-Held Electronic Books Selector Guide and Typical Application Circuits appear at end of data sheet. AutoShutdown Plus is a trademark of Maxim Integrated Products. 16 SSOP 20 TSSOP MAX3317ECAP 0°C to +70°C 20 SSOP MAX3317EEUP -40°C to +85°C MAX3317EEAP -40°C to +85°C MAX3318ECUP 20 TSSOP 20 SSOP 0°C to +70°C 20 TSSOP MAX3318ECAP 0°C to +70°C 20 SSOP MAX3318EEUP -40°C to +85°C 20 TSSOP MAX3318EEAP -40°C to +85°C 20 SSOP MAX3319ECAE 0°C to +70°C 16 SSOP MAX3319EEAE -40°C to +85°C 16 SSOP Pin Configurations READY 1 20 FORCEOFF C1+ 2 19 VCC V+ 3 18 GND C1- 4 17 T1OUT MAX3318E C2- 6 Cellular Phones 20 TSSOP 0°C to +70°C C2+ 5 Pagers PIN-PACKAGE MAX3316ECUP 16 R1IN 15 R1OUT V- 7 14 FORCEON T2OUT 8 13 T1IN R2IN 9 12 T2IN R2OUT 10 11 INVALID SSOP/TSSOP Pin Configurations continued at end of data sheet. ________________________________________________________________ Maxim Integrated Products 1 For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. MAX3316E–MAX3319E _______________General Description The MAX3316E–MAX3319E are 2.5V powered RS-232 compatible transceivers. These devices feature shutdown (MAX3317E), AutoShutdown Plus™ (MAX3318E/ MAX3319E), and enhanced electrostatic discharge (ESD) protection integrated into the chip. All transmitter outputs and receiver inputs are protected to ±15kV using the IEC 1000-4-2 Air-Gap Discharge method, ±8kV using the IEC 1000-4-2 Contact Discharge method, and ±15kV using the Human Body Model. MAX3316E–MAX3319E ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers ABSOLUTE MAXIMUM RATINGS VCC to GND ..............................................................-0.3V to +6V V+ to GND (Note 1) ..................................................-0.3V to +7V V- to GND (Note 1) ...................................................-7V to +0.3V V+ + |V-| (Note 1) .................................................................+13V Input Voltages T_IN, EN, SHDN, FORCEON, FORCEOFF to GND ...............................................-0.3V to +6V R_IN to GND ..................................................................±25V Output Voltages T_OUT to GND............................................................±13.2V R_OUT, INVALID, READY to GND .......-0.3V to (VCC + 0.3V) Short-Circuit Duration, T_OUT to GND.......................Continuous Continuous Power Dissipation (TA = +70°C) 16-Pin SSOP (derate 7.14mW/°C above +70°C) .......571mW 20-Pin SSOP (derate 8.00mW/°C above +70°C) .......640mW 20-Pin TSSOP (derate 7.00mW/°C above +70°C) .....559mW Operating Temperature Range MAX331_EC_ _ .................................................0°C to +70°C MAX331_EE_ _ ..............................................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V CC = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V, TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC CHARACTERISTICS (VCC = +2.5V, TA = +25°C) AutoShutdown Plus Supply Current FORCEON = GND, FORCEOFF = VCC, all R_IN idle, all T_IN idle (MAX3318E/MAX3319E) 1 10 µA Shutdown Supply Current SHDN = GND (MAX3317E); FORCEOFF = GND (MAX3318E/MAX3319E) 1 10 µA Supply Current SHDN = VCC, no load (MAX3317E); FORCEON = FORCEOFF = VCC, no load (MAX3318E/MAX3319E) 0.3 1 mA LOGIC INPUTS Input Logic Threshold Low T_IN, EN, SHDN, FORCEON, FORCEOFF Input Logic Threshold High T_IN, EN, SHDN, FORCEON, FORCEOFF 0.3 · VCC 0.7 · VCC V 0.3 Transmitter Input Hysteresis V V T_IN, EN, SHDN, FORCEON, FORCEOFF ±0.01 ±1 µA Output Leakage Current EN = VCC (MAX3317E), receivers disabled ±0.05 ±10 µA Output Voltage Low IOUT = 0.5mA 0.1 · VCC V Output Voltage High IOUT = -0.5mA Input Leakage Current RECEIVER OUTPUTS 0.9 · VCC V RECEIVER INPUTS -25 Input Voltage Range Input Threshold Low TA = +25°C Input Threshold High TA = +25°C 0.7 · VCC TA = +25°C 3 5 ±3.7 ±4 Input Hysteresis Input Resistance +25 V 0.3 · VCC V V 0.3 V 7 kΩ TRANSMITTER OUTPUTS Output Voltage Swing 2 All transmitter outputs loaded with 3kΩ to ground _______________________________________________________________________________________ V ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers (V CC = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V, TA = +25°C.) PARAMETER SYMBOL Output Resistance CONDITIONS VCC = 0, transmitter output = ±2V MIN TYP 300 10M ±25 Output Short-Circuit Current VCC = 0 or 2.25V to 3.0V, VOUT = ±12V, transmitters disabled Output Leakage Current MAX UNITS ±60 mA ±25 µA Ω ESD PROTECTION R_IN, T_OUT Human Body Model ±15 IEC 1000-4-2 Air-Gap Discharge method ±15 IEC 1000-4-2 Contact Discharge method ±8 kV AutoShutdown Plus (FORCEON = GND, FORCEOFF = VCC) (MAX3318E/MAX3319E) Receiver Input Threshold to INVALID Output High Figure 4a Receiver Input Threshold to INVALID Output Low Figure 4a INVALID, READY Output Voltage Low IOUT = 0.5mA INVALID, READY Output Voltage High IOUT = -0.5mA 2.7 Positive threshold Negative threshold -2.7 -0.3 0.3 0.1 · VCC 0.9 · VCC V V V V Receiver Positive or Negative Threshold to INVALID High tINVH VCC = 2.5V, Figure 4b 1 µs Receiver Positive or Negative Threshold to INVALID Low tINVL VCC = 2.5V, Figure 4b 30 µs Receiver or Transmitter Edge to Transmitters Enabled tWU VCC = 2.5V, Figure 4b (Note 2) 100 µs Receiver or Transmitter Edge to Transmitters Shutdown tAUTOSHDN VCC = 2.5V, Figure 4b (Note 2) 15 30 60 s TIMING CHARACTERISTICS (V CC = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V, TA = +25°C.) PARAMETER SYMBOL Maximum Data Rate Receiver Propagation Delay CONDITIONS RL = 3kΩ, CL = 1000pF, one transmitter switching tPHL tPLH Receiver Output Enable Time R_IN to R_OUT, CL = 150pF MIN TYP 460 MAX UNITS kbps 0.175 0.175 µs Normal operation (MAX3317E) 250 ns Normal operation (MAX3317E) 250 ns Transmitter Skew |tPHL - tPLH| (Note 3) 100 ns Receiver Skew |tPHL - tPLH| 50 ns Receiver Output Disable Time _______________________________________________________________________________________ 3 MAX3316E–MAX3319E ELECTRICAL CHARACTERISTICS (continued) TIMING CHARACTERISTICS (continued) (V CC = +2.25V to +3.0V, C1–C4 = 0.1µF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at V CC = +2.5V, TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN VCC = 2.5V, TA = +25°C, RL = 3kΩ to 7kΩ, measured from +3V to -3V or -3V to +3V, CL = 150pF to 2500pF Transition-Region Slew Rate TYP 4 MAX UNITS 30 V/µs Note 2: A transmitter/receiver edge is defined as a transition through the transmitter/receiver input logic thresholds. Note 3: Transmitter skew is measured at the transmitter zero crosspoints. Typical Operating Characteristics (VCC = +2.5V, C1–C4 = 0.1µF, 460kbps data rate, all transmitters loaded with 3kΩ, TA = +25°C, unless otherwise noted.) MAX3316E/MAX3317E TRANSMITTER OUTPUT VOLTAGE vs. SUPPLY VOLTAGE MAX3316E/MAX3317E SUPPLY CURRENT vs. SUPPLY VOLTAGE 230kbps 6 4 20kbps T1 TRANSMITTING AT SPECIFIED DATA RATE T2 TRANSMITTING AT 20kbps CL = 1000pF 2.25 2.45 2.65 2.85 3.05 3.25 0 MAX3316E TOC02 -2 T_OUT- -4 -6 3.45 3.65 2.25 2.45 2.65 2.85 3.05 3.25 3.45 3.65 MAX3316E/MAX3317E TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE MAX3316E/MAX3317E SLEW RATE vs. LOAD CAPACITANCE T_OUT+ 3 10 0 -1 FOR DATA RATES UP TO 460kps 8 SLEW RATE (V/µs) T1 TRANSMITTING AT 460kbps T2 TRANSMITTING AT 20kbps -SLEW 6 +SLEW 4 -2 2 -3 T_OUT- -4 0 -5 0 1000 2000 LOAD CAPACITANCE (pF) 4 T1 TRANSMITTING AT 460kbps T2 TRANSMITTING AT 20kbps CL = 1000pF VCC (V) 4 1 2 VCC (V) 5 2 4 MAX3316E TOC04 0 T_OUT+ MAX3316E TOC03 2 6 TRANSMITTER OUTPUT VOLTAGE (V) 460kbps 8 SUPPLY CURRENT (mA) MAX3316E TOC01 10 TRANSMITTER OUTPUT VOLTAGE (V) MAX3316E–MAX3319E ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers 3000 0 1000 2000 3000 LOAD CAPACITANCE (pF) _______________________________________________________________________________________ ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers 15 10 20kbps 20kbps 6 T1 TRANSMITTING AT SPECIFIED DATA RATE T2 TRANSMITTING AT 20kbps CL = 1000pF 3 5 0 0 0 1000 2000 LOAD CAPACITANCE (pF) T_OUT+ 3 T1 TRANSMITTING AT 460kbps T2 TRANSMITTING AT 20kbps 1 0 -1 2.65 2.85 MAX3316E TOC07 2 T1 TRANSMITTING AT 460kbps T2 TRANSMITTING AT 20kbps CL = 1000pF 0 -2 T_OUT- -4 3.05 3.25 3.45 3.65 2.25 2.45 2.65 2.85 3.05 3.25 3.45 VCC (V) VCC (V) MAX3318E/MAX3319E SLEW RATE vs. LOAD CAPACITANCE MAX3318E/MAX3319E OPERATING SUPPLY CURRENT vs. LOAD CAPACITANCE 8 SLEW RATE (V/µs) 2 2.45 10 MAX3316E TOC08 TRANSMITTER OUTPUT VOLTAGE (V) 4 T_OUT+ 4 -6 2.25 3000 MAX3318E/MAX3319E TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE 5 MAX3316E TOC06 230kbps 9 TRANSMITTER OUTPUT VOLTAGE (V) 230kbps 12 6 -SLEW 6 35 +SLEW 4 -2 3.65 T1 TRANSMITTING AT SPECIFIED DATA RATE T2 TRANSMITTING AT 20kbps 30 SUPPLY CURRENT (mA) 460kbps 20 460kbps MAX3316E TOC09 25 15 SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) 30 T1 TRANSMITTING AT SPECIFIED DATA RATE T2 TRANSMITTING AT 20kbps MAX3316E TOC05 35 MAX3318E/MAX3319E TRANSMITTER OUTPUT VOLTAGE vs. SUPPLY VOLTAGE MAX3318E/MAX3319E SUPPLY CURRENT vs. SUPPLY VOLTAGE MAX3316E TOC10 MAX3316E/MAX3317E OPERATING SUPPLY CURRENT vs. LOAD CAPACITANCE 25 460kbps 20 230kbps 15 10 20kbps 2 -3 T_OUT- -4 5 FOR DATA RATES UP TO 460kbs 0 -5 0 1000 2000 LOAD CAPACITANCE (pF) 3000 0 1000 2000 LOAD CAPACITANCE (pF) 0 3000 0 1000 2000 LOAD CAPACITANCE (pF) 3000 _______________________________________________________________________________________ 5 MAX3316E–MAX3319E Typical Operating Characteristics (continued) (VCC = +2.5V, C1–C4 = 0.1µF, 460kbps data rate, all transmitters loaded with 3kΩ, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +2.5V, C1–C4 = 0.1µF, 460kbps data rate, all transmitters loaded with 3kΩ, TA = +25°C, unless otherwise noted.) 300 MAX3316E/MAX3317E 200 MAX3318E/MAX3319E 100 20 15 10 500 1000 1500 2000 2500 -40 3000 120 80 0 0 0 160 40 5 0 MAX3316E TOC13 25 200 READY TURN-OFF TIME (ns) 400 30 MAX3316E TOC12 T1 TRANSMITTING AT 460kbps T2 TRANSMITTING AT 20kbps READY TURN-ON TIME (µs) MAX3316E TOC11 500 MAX3318E/MAX3319E READY TURN-OFF TIME vs. TEMPERATURE MAX3318E/MAX3319E READY TURN-ON TIME vs. TEMPERATURE TRANSMITTER SKEW vs. LOAD CAPACITANCE (tPLH - tPHL) TRANSMITTER SKEW (ns) MAX3316E–MAX3319E ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers -20 0 20 40 60 80 -40 -20 0 20 40 60 80 TEMPERATURE (°C) TEMPERATURE (°C) LOAD CAPACITANCE (pF) Pin Description PIN NAME MAX3316E SSOP TSSOP 1 2 2 2 2 C1+ 2 3 3 3 3 V+ +2 · VCC Generated by the Charge Pump 3 4 4 4 4 C1- Negative Terminal of Voltage-Doubler ChargePump Capacitor 4 5 5 5 5 C2+ Positive Terminal of Inverting Charge-Pump Capacitor 5 6 6 6 6 C2- Negative Terminal of Inverting Charge-Pump Capacitor 6 7 7 7 7 V- 7, 14 8, 17 8, 17 8, 17 13 T_OUT 8, 13 9, 16 9, 16 9, 16 8 R_IN RS-232 Receiver Inputs 9, 12 12, 15 10, 15 10, 15 9 R_OUT CMOS Receiver Outputs 10, 11 13, 14 12, 13 12, 13 11 T_IN CMOS Transmitter Inputs 15 18 18 18 14 GND Ground 16 19 19 19 15 VCC +2.25V to +3.0V Single-Supply Voltage 1 — — EN Receiver Enable, Active Low 1, 10, 11, 20 11, 14 — — N.C. — — 6 FUNCTION MAX3317E MAX3318E MAX3319E Positive Terminal of Voltage-Doubler ChargePump Capacitor -2 · VCC Generated by the Charge Pump RS-232 Transmitter Outputs No Connection _______________________________________________________________________________________ ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers PIN MAX3316E SSOP TSSOP NAME FUNCTION MAX3317E MAX3318E MAX3319E — 20 — — SHDN Shutdown Control, Active Low — — 1 1 READY Ready to Transmit Output, Active High. READY is enabled high when V- goes below -3.5V and the device is ready to transmit. — — 11 10 INVALID Valid Signal Detector Output, Active Low. A logic high indicates that a valid RS-232 level is present on a receiver input. — — 14 12 FORCEON Force-On Input, Active High. Drive high to override AutoShutdown Plus, keeping transmitters and receivers on (FORCEOFF must be high) (Table 1). FORCEOFF Force-Off Input, Active Low. Drive low to shut down transmitters, receivers, and charge pump. This overrides AutoShutdown Plus and FORCEON (Table 1). — — 20 16 Detailed Description Dual Charge-Pump Voltage Converter The MAX3316E–MAX3319Es’ internal power supply consists of a regulated dual charge pump that provides output voltages of +4.4V (doubling charge pump) and -4.3V (inverting charge pump), over the +2.25V to +3.0V range. The charge pump operates in discontinuous mode: if the output voltages are less than 4.4V, the charge pump is enabled; if the output voltages exceed 4.4V, the charge pump is disabled. Each charge pump requires a flying capacitor (C1, C2) and a reservoir capacitor (C3, C4) to generate the V+ and V- supplies. The READY output (MAX3318E/MAX3319E) is low when the charge pumps are disabled in shutdown mode. The READY signal asserts high when V- goes below -2.75V. RS-232 Compatible Transmitters The MAX3316E–MAX3319Es’ transmitters are inverting level translators that convert CMOS-logic levels to RS-232 compatible voltage levels. They guarantee a 460kbps data rate with worst-case loads of 3kΩ in parallel with 1000pF, providing compatibility with PC-to-PC communication software (such as LapLink™). The MAX3317E’s transmitters are turned off (high impedance) when SHDN is asserted low, putting the device in shutdown mode. The MAX3318E/MAX3319Es’ LapLink is a trademark of Traveling Software. transmitters are turned off (high impedance) when FORCEOFF is asserted low, or when the AutoShutdown Plus circuitry senses that all receiver and transmitter inputs are inactive for more than 30 seconds. The transmitter outputs can be driven to ±12V when power is off. The transmitter inputs do not have internal pull-up resistors. Connect unused inputs to GND or VCC. RS-232 Receivers The MAX3316E–MAX3319Es’ receivers convert ±3.7V to ±13.2V RS-232 signal levels into CMOS-logic output levels. The receivers are rated to receive signals up to ±25V. The MAX3316E/MAX3318E/MAX3319Es’ receivers feature inverting outputs that always remain active (Table 1). The MAX3317E’s receivers have inverting, three-state outputs. In shutdown, the receivers can be active or inactive (Table 2). The MAX3318E/MAX3319E feature an INVALID output that is asserted low when no valid RS-232 voltage levels have been detected on all receiver inputs. Because INVALID indicates the receiver’s input condition, it is independent of the states of FORCEON and FORCEOFF. MAX3317E Shutdown Mode Supply current falls to less than 1µA in shutdown mode (SHDN = low). When shut down, the device’s charge pumps are turned off, V+ is pulled down to VCC, V- is pulled to ground, and the transmitter outputs are disabled (high impedance). The time required to exit shut- _______________________________________________________________________________________ 7 MAX3316E–MAX3319E Pin Description (continued) MAX3316E–MAX3319E ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers Table 1. Output Control Truth Table (MAX3318E/MAX3319E) OPERATION STATUS RECEIVER OR VALID RECEIVER TRANSMITTER LEVEL EDGE WITHIN 30s FORCEON FORCEOFF Shutdown (Forced Off) X 0 X Normal Operation (Forced On) 1 1 Normal Operation (AutoShutdown Plus) 0 Shutdown (AutoShutdown Plus) T_OUT R_OUT X High-Z Active X X Active Active 1 X Yes Active Active 0 1 X No High-Z Active Normal Operation INVALID* 1 Yes X Active Active Normal Operation INVALID* 1 X Yes Active Active Shutdown INVALID* 1 No No High-Z Active Normal Operation (AutoShutdown) INVALID** INVALID** Yes X Active Active Shutdown (AutoShutdown) INVALID** INVALID** No X High-Z Active X = Don’t care *INVALID connected to FORCEON **INVALID connected to FORCEON and FORCEOFF Table 2. Shutdown and Enable Control Truth Table (MAX3317E) SHDN 0 EN 0 T_OUT High-Z Active 0 1 High-Z High-Z 1 0 Active Active 1 1 Active High-Z R_OUT down is typically 30µs, as shown in Figure 2. Connect SHDN to VCC if the shutdown mode is not used; SHDN has no effect on R_OUT. MAX3318E/MAX3319E AutoShutdown Plus Mode Maxim’s AutoShutdown Plus feature on the MAX3318E/ MAX3319E allows the supply current to fall to 1µA. These devices will enter the AutoShutdown Plus mode if FORCEOFF is high, FORCEON is low, and they do not 8 sense a valid signal transition on any receiver or transmitter input for 30 seconds. This may occur if the RS-232 cable is disconnected or if the peripheral transmitters are turned off, and the UART driving the transmitter inputs is inactive. The system turns on again when a valid transition is applied to any RS-232 receiver or transmitter input. As a result, the system saves power without changes to the existing BIOS or operating system. Figure 4a depicts valid and invalid RS-232 receiver voltage levels. INVALID indicates the receiver input’s condition and is independent of FORCEON and FORCEOFF states. Figure 3 and Table 1 summarize the operating modes of the MAX3318E/MAX3319E. FORCEON and FORCEOFF override AutoShutdown Plus circuitry. When neither control is asserted, the IC selects between these states automatically based on the last receiver or transmitter edge received. When shut down, the device’s charge pumps turn off, V+ is pulled to VCC, V- is pulled to ground, the transmitter outputs are high impedance, and READY is driven low. The time required to exit shutdown is typically 30µs (Figure 2). _______________________________________________________________________________________ ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers MAX3316E–MAX3319E +2.5V CBYPASS 0.1µF VCC C1+ C1 0.1µF C3 0.1µF C1C2+ C2 0.1µF V+ C2- MAX3316E MAX3317E MAX3318E MAX3319E V- +5V C4 0.1µF T_ OUT T_ IN RX 1000pF R_ IN R_ OUT TX RS-232 COMPLIANT TRANSCEIVER GND Figure 1a. RS-232 Compatibility Circuit VCC OR SHDN (MAX3317E) 5V/div T1 IN MAX3316E–MAX3319E FORCEOFF (MAX3318E/MAX3319E) 2V/div T1 5V/div T1 OUT MAX3316E–MAX3319E 2V/div T2 RS-232 COMPLIANT RECEIVER OUTPUT 5V/div 10µs/div Figure 1b. MAX3316E–MAX3319E Transmitter Output Compatibility with an RS-232 Receiver Figure 2. Transmitter Outputs when Exiting Shutdown or Powering Up _______________________________________________________________________________________ 9 By connecting FORCEON to INVALID, the MAX3318E/ MAX3319E shut down when no valid receiver level is detected and wake up when a valid receiver level is detected. A system with AutoShutdown Plus may need time to wake up. Figure 5 shows a circuit that forces the transmitters on for 100ms, allowing enough time for the other system to realize that the MAX3318E/MAX3319E is awake. If the other system outputs valid RS-232 signal transitions within that time, the RS-232 ports on both systems remain enabled. Connecting to the PC (MAX3318E/MAX3319E) If direct software control is desired, use INVALID to indicate DTR or ring indicator (RI) signal. This can be used to connect a hand-held device to a PC. One example is using the Hot Sync™ function on a personal digital assistant (PDA). The transmitter and receiver signals (T_OUT and R_IN) are used for communication, while INVALID causes a change of state on RI. The change of state on RI will trigger an interrupt on the PC and allow communication to begin between the device and the PC. This eliminates the need for the PC to poll constantly the receiver or transmitter lines to determine if the device is connected. ±15kV ESD Protection All the pins on the MAX3316E–MAX3319E are protected against ESDs encountered during handling and assembly. The driver outputs and receiver inputs have extra protection against static electricity. Maxim’s engineers have developed state-of-the-art structures to protect these pins against ESD of ±15kV without damage. The ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down. After an ESD event, Maxim’s E versions keep working without latchup, whereas competing products can latch and must be powered down to remove latchup. ESD protection can be tested in various ways; the transmitter outputs and receiver inputs of the product family are characterized for protection to the following limits: • ±15kV using the Human Body Model • ±8kV using the IEC 1000-4-2 Contact Discharge method • ±15kV using IEC 1000-4-2 Air-Gap method ESD Test Conditions ESD performance depends on a variety of conditions. Contact Maxim for a reliability report that documents test setup, test methodology, and test results. Hot Sync is a trademark of 3Com. 10 +0.3V R_IN 30µs TIMER R -0.3V INVALID INVALID ASSERTED IF ALL RECEIVER INPUTS ARE BETWEEN +0.3V AND -0.3V FOR AT LEAST 30µs. Figure 3a. INVALID Functional Diagram, INVALID Low +2.7V R_IN 30µs TIMER R -2.7V INVALID INVALID DEASSERTED IF ANY RECEIVER INPUT HAS BEEN BETWEEN +2.7V AND -2.7V FOR LESS THAN 30µs. Figure 3b. INVALID Functional Diagram, INVALID High INVALID HIGH +2.7V RECEIVER INPUT LEVELS MAX3316E–MAX3319E ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers INDETERMINATE +0.3V 0 INVALID LOW -0.3V INDETERMINATE -2.7V INVALID HIGH Figure 4a. Receiver Positive/Negative Thresholds for INVALID Human Body Model Figure 6a shows the Human Body Model, and Figure 6b shows the current waveform it generates when discharged into low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest, which is then discharged into the test device through a 1.5kΩ resistor. ______________________________________________________________________________________ ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers MAX3316E–MAX3319E RECEIVER INPUTS INVALID } REGION TRANSMITTER INPUTS TRANSMITTER OUTPUTS INVALID OUTPUT VCC tINVL tINVH 0 tAUTOSHDN tAUTOSHDN tWU tWU *VCC OUTPUT 0 V+ VCC 0 V- MAX3318E/MAX3319E Figure 4b. AutoShutdown Plus, INVALID, and READY Timing Diagram POWERMANAGEMENT UNIT RC 1M MASTER SHDN LINE 0.1µF 1M CHARGE-CURRENT LIMIT RESISTOR FORCEOFF FORCEON MAX3318E MAX3319E Figure 5. AutoShutdown Plus Initial Turn-On to Wake Up a Mouse or Another System HIGHVOLTAGE DC SOURCE Cs 100pF RD 1500Ω DISCHARGE RESISTANCE STORAGE CAPACITOR DEVICE UNDER TEST Figure 6a. Human Body ESD Test Model ______________________________________________________________________________________ 11 IEC 1000-4-2 The IEC 1000-4-2 standard covers ESD testing and performance of finished equipment; it does not specifically refer to ICs. The MAX3316E–MAX3319E help you design equipment that meets Level 4 (the highest level) of IEC 1000-4-2 without the need for additional ESDprotection components. The major difference between tests done using the Human Body Model and IEC 1000-4-2 is higher peak current in IEC 1000-4-2 because series resistance is lower in the IEC 1000-4-2 model. Hence, the ESD withstand voltage measured to IEC 1000-4-2 is generally lower than that measured using the Human Body Model. Figure 7a shows the IEC 1000-4-2 model, and Figure 7b shows the current waveform for the 8kV, IEC 1000-4-2, Level 4, ESD Contact Discharge test. The Air-Gap Discharge test involves approaching the device with a charged probe. The Contact Discharge method connects the probe to the device before the probe is energized. IP 100% 90% Applications Information PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE) AMPERES 36.8% 10% 0 0 TIME tRL tDL CURRENT WAVEFORM Figure 6b. Human Body Current Waveform RC 50M to 100M CHARGE-CURRENT LIMIT RESISTOR Machine Model The Machine Model for ESD tests all pins using a 200pF storage capacitor and zero discharge resistance. Its objective is to emulate the stress caused by contact that occurs with handling and assembly during manufacturing. All pins require this protection during manufacturing, not just RS-232 inputs and outputs. Therefore, after PC board assembly, the Machine Model is less relevant to I/O ports. Ir HIGHVOLTAGE DC SOURCE Cs 150pF RD 330Ω DISCHARGE RESISTANCE STORAGE CAPACITOR DEVICE UNDER TEST Figure 7a. IEC 1000-4-2 ESD Test Model RS-232 Compatible Operation The MAX3316E–MAX3319E do not meet EIA-232 requirements for transmitter output voltage levels. EIA-232 compliance specifies transmitter output voltage swings of ±5V when loaded with 3kΩ and 2500pF. The receiver inputs are fully EIA-232 compliant. The MAX3316E–MAX3319E will function properly with most modern RS-232 interfaces. This allows RS-232 compatible communication in low-voltage systems without the added expense of a voltage tripler or switchedmode power supply. I 100% 90% I PEAK MAX3316E–MAX3319E ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers 10% t r = 0.7ns to 1ns t 30ns 60ns Figure 7b. IEC 1000-4-2 ESD Generator Current Waveform 12 ______________________________________________________________________________________ ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers VCC CBYPASS VCC C1+ C1 C1C2+ C2 Transmitter Outputs when Exiting Shutdown Figure 2 shows two transmitter outputs when exiting shutdown mode. As they become active, the two transmitter outputs are shown going to opposite RS-232 compatible levels (one transmitter input is high, the other is low). Each transmitter is loaded with 3kΩ in parallel with 2500pF. The transmitter outputs display no ringing or undesirable transients as they come out of shutdown. Note that the transmitters are enabled only when the magnitude of V- exceeds approximately -3V. V+ C3* MAX3316E MAX3317E MAX3318E MAX3319E VC4 C2- T_ OUT T_ IN R_ IN R_ OUT Power-Supply Decoupling In most circumstances, a 0.1µF bypass capacitor is adequate. In applications that are sensitive to powersupply noise, decouple VCC to ground with a capacitor of the same value as charge pump capacitor C1. Connect bypass capacitors as close to the IC as possible. MAX3316E–MAX3319E Capacitor Selection The capacitor type used for C1–C4 is not critical for proper operation; polarized or nonpolarized capacitors can be used. The charge pump requires 0.1µF capacitors. Increasing the capacitor values (e.g., by a factor of 2) reduces ripple on the transmitter outputs and slightly reduces power consumption. C2, C3, and C4 can be increased without changing C1’s value. However, do not increase C1 without also increasing the values of C2, C3, C4, and CBYPASS to maintain proper ratios (C1 to other capacitors). When using the minimum-required capacitor values, make sure the capacitor value does not degrade excessively with temperature. If in doubt, use capacitors with a higher nominal value. The capacitor’s equivalent series resistance (ESR), which usually rises at low temperatures, influences the amount of ripple on V+ and V-. 5k FORCEON** VCC FORCEOFF** 1000pF GND *C3 CAN BE RETURNED TO VCC OR GND. **MAX3318E/MAX3319E Figure 8. Loopback Test Circuit 2V/div T1 IN High Data Rates The MAX3316E–MAX3319E maintain RS-232 compatible ±3.7V minimum transmitter output voltage even at high data rates. Figure 8 shows a transmitter loopback test circuit. Figure 9 shows a loopback test result at 230kbps. For Figure 9, all transmitters were driven simultaneously at 230kbps into EIA/TIA-562 loads in parallel with 1000pF. Chip Information TRANSISTOR COUNT: 1130 5V/div T1 OUT R1 OUT 2V/div Figure 9. Loopback Test Result at 230kbps ______________________________________________________________________________________ 13 ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers MAX3316E–MAX3319E Pin Configurations (continued) TOP VIEW C1+ 1 16 VCC V+ 2 15 GND C1- 3 C2+ 4 14 T1OUT MAX3316E C2- 5 12 R1OUT V- 6 11 T1IN 10 T2IN T2OUT 7 9 R2IN 8 SSOP 14 13 R1IN R2OUT N.C. 1 20 N.C. EN 1 C1+ 2 19 VCC C1+ 2 19 VCC V+ 3 18 GND V+ 3 18 GND C1- 4 C2+ 5 MAX3316E C2- 6 17 T1OUT C1- 4 16 R1IN C2+ 5 15 R1OUT C2- 6 20 SHDN 17 T1OUT MAX3317E 16 R1IN 15 R1OUT V- 7 14 T1IN V- 7 14 N.C. T2OUT 8 13 T2IN T2OUT 8 13 T1IN R2IN 9 12 T2IN R2OUT 10 11 N.C. R2IN 9 12 R2OUT N.C. 10 11 N.C. TSSOP SSOP/TSSOP READY 1 16 FORCEOFF C1+ 2 15 VCC V+ 3 14 GND C1- 4 MAX3319E 13 T1OUT C2+ 5 12 FORCEON C2- 6 11 T1IN 10 INVALID V- 7 9 R1IN 8 SSOP ______________________________________________________________________________________ R1OUT ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers PART NO. OF DRIVERS/ RECEIVERS GUARANTEED DATA RATE (kbps) READY OUTPUT SHUTDOWN MAX3316E 2/2 460 — MAX3317E 2/2 460 — ✓ MAX3318E 2/2 460 — ✓ MAX3319E 1/1 460 ✓ AutoShutdown Plus — — — ✓ — ✓ Typical Application Circuits +2.5V +2.5V 19 0.1µF C1 0.1µF 2 C1+ 4 5 C2 0.1µF 6 V+ 3 C3* 0.1µF C1- MAX3317E C2+ V- 0.1µF 0.1µF T1OUT 17 T2OUT 8 12 T2IN CMOS OUTPUTS 5k 10 R2OUT R2IN 9 5 VCC V+ RS-232 COMPATIBLE OUTPUTS C2+ MAX3316E GND 18 SHDN V- 6 C4 0.1µF T1OUT 14 CMOS INPUTS T2OUT 7 10 T2IN RS-232 COMPATIBLE OUTPUTS R1IN 13 CMOS OUTPUTS 5k 9 R2OUT R2IN 8 5k EN C3* 0.1µF C2- 12 R1OUT RS-232 COMPATIBLE INPUTS 2 C1- 11 T1IN R1IN 16 15 R1OUT 3 4 C4 0.1µF CMOS INPUTS 1 1 C1+ 7 C2- 13 T1IN 16 0.1µF VCC RS-232 COMPATIBLE INPUTS 5k 20 *C3 CAN BE RETURNED TO EITHER VCC OR GROUND. GND 15 CIRCUIT SHOWN IS FOR THE 16-PIN SSOP. Typical Application Circuits continue on next page. ______________________________________________________________________________________ 15 MAX3316E–MAX3319E Selector Guide MAX3316E–MAX3319E ±15kV ESD-Protected, 2.5V, 1µA, 460kbps, RS-232 Compatible Transceivers Typical Application Circuits (continued) +2.5V CBYPASS C1 0.1µF +2.5V 2 C1+ 4 5 C2 0.1µF CMOS INPUTS 19 0.1µF 6 C1- 3 V+ MAX3318E C2+ V- C3 0.1µF 2 C1+ C1 0.1µF 4 7 C2- 13 T1IN T1OUT 17 12 T2IN T2OUT 8 C4 0.1µF RS-232 COMPATIBLE OUTPUTS 15 0.1µF CBYPASS VCC 5 C2 0.1µF 6 CMOS INPUT CMOS OUTPUT C1- VCC 3 V+ MAX3319E C2+ V- C3 0.1µF 7 C2- 11 T1IN T1OUT 13 R1IN 8 9 R1OUT 5k CMOS OUTPUTS RS-232 COMPATIBLE INPUTS 5k 12 5k 14 1 READY R2IN 9 10 R2OUT READY RS-232 COMPATIBLE OUTPUT RS-232 COMPATIBLE INPUT R1IN 16 15 R1OUT 1 C4 0.1µF AutoShutdown Plus INVALID 11 FORCEOFF 20 FORCEON GND AutoShutdown Plus FORCEOFF 16 FORCEON GND TO POWERMANAGEMENT UNIT INVALID 10 TO POWERMANAGEMENT UNIT VCC 14 VCC 18 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.