19-2143; Rev 1; 12/01 ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters The MAX3040–MAX3045 is a family of 5V quad RS485/RS-422 transmitters designed for digital data transmission over twisted-pair balanced lines. All transmitter outputs are protected to ±10kV using the Human Body Model. In addition the MAX3040–MAX3045 withstand ±4kV per IEC 1000-4-4 Electrical Fast Transient/Burst Stressing. The MAX3040/MAX3043 (250kbps) and the MAX3041/MAX3044 (2.5Mbps) are slew-rate limited transmitters that minimize EMI and reduce reflections caused by improperly terminated cables, thus allowing error-free transmission. The MAX3040–MAX3045 feature a hot-swap capability* that eliminates false transitions on the data cable during power-up or hot insertion. The MAX3042B/MAX3045B are optimized for data transfer rates up to 20Mbps, the MAX3041/MAX3044 for data rates up to 2.5Mbps, and the MAX3040/MAX3043 for data rates up to 250kbps. The MAX3040–MAX3045 offer optimum performance when used with the MAX3093E or MAX3095 5V quad differential line receivers or MAX3094E/MAX3096 3V quad differential line receivers. The MAX3040–MAX3045 are ESD-protected pin-compatible, low-power upgrades to the industry-standard ‘SN75174 and ‘DS26LS31C. They are available in spacesaving TSSOP, narrow SO, and wide SO packages. Features ♦ ESD Protection: ±10kV—Human Body Model ♦ Single +5V Operation ♦ Guaranteed Device-to-Device Skew (MAX3040/MAX3041/MAX3043/MAX3044) ♦ Pin-Compatible with ‘SN75174, ‘26LS31C and LTC487 ♦ Hot-Swappable for Telecom Applications ♦ Up to 20Mbps Data Rate (MAX3042B/MAX3045B) ♦ Slew-Rate Limited (Data Rates at 2.5Mbps and 250kbps) ♦ 2nA Low-Power Shutdown Mode ♦ 1mA Operating Supply Current ♦ ±4kV EFT Fast Transient Burst Immunity per IEC 1000-4-4 ♦ Level 2 Surge Immunity per IEC 1000-4-5, Unshielded Cable Model ♦ Ultra-Small 16-Pin TSSOP, 16-Pin Narrow SO, and Wide 16-Pin SO Ordering Information DATA RATE PART TEMP RANGE PIN-PACKAGE MAX3040CUE 0°C to +70°C 16 TSSOP 250kbps MAX3040CSE 0°C to +70°C 16 Narrow SO 250kbps *Patent pending Applications Telecommunications Equipment MAX3040CWE 0°C to +70°C 16 Wide SO 250kbps Industrial Motor Control MAX3040EUE -40°C to +85°C 16 TSSOP 250kbps Transmitter for ESD-Sensitive Applications MAX3040ESE -40°C to +85°C 16 Narrow SO 250kbps Hand-Held Equipment MAX3040EWE -40°C to +85°C 16 Wide SO 250kbps Industrial PLCs Ordering Information continued at end of data sheet. Networking PART Pin Configurations Selector Guide DATA RATE (bps) INDUSTRY STANDARD PINOUT TOP VIEW T1IN 1 16 VCC MAX3040 250k 75174, 34C87, LTC487 Y1 2 15 T4IN MAX3041 2.5M 75174, 34C87, LTC487 Z1 3 14 Y4 MAX3042B 20M 75174, 34C87, LTC487 EN12 4 MAX3043 250k 26LS31 Z2 5 MAX3044 2.5M 26LS31 Y2 6 11 Z3 MAX3045B 20M 26LS31 T2IN 7 10 Y3 GND 8 9 MAX3040 MAX3041 MAX3042B 13 Z4 12 EN34 T3IN 16 TSSOP/SO Pin Configurations continued at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX3040–MAX3045 General Description MAX3040–MAX3045 ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters ABSOLUTE MAXIMUM RATINGS All voltages referenced to ground (GND). Supply Voltage (VCC).............................................................+7V Control Input Voltage (EN, EN, EN_) .........-0.3V to (VCC + 0.3V) Driver Input Voltage (T_IN).........................-0.3V to (VCC + 0.3V) Driver Output Voltage (Y_, Z_) (Driver Disabled) .............................................-7.5V to +12.5V Driver Output Voltage (Y_, Z_) (Driver Enabled) .................................................-7.5V to +10V Continuous Power Dissipation (TA = +70°C) 16-Pin TSSOP (derate 9.4mW/°C above +70°C) ..........755mW 16-Pin Narrow SO (derate 8.70mW/°C above +70°C) ..696mW 16-Pin Wide SO (derate 9.52mW/°C above +70°C) .....762mW Operating Temperature Range MAX304_C_E .......................................................0°C to +70°C MAX304_E_E ....................................................-40°C to +85°C Maximum Junction Temperature .....................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C 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 (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DRIVER Driver Differential Output Change in Magnitude of Differential Output Voltage Driver Common-Mode Output Voltage Change In Magnitude of Common-Mode Voltage Input High Voltage Input Low Voltage Hot-Swap Driver Input Current VOD ∆VOD VOC ∆VOC Figure 1, R = 50Ω 2.0 Figure 1, R = 27Ω 1.5 Figure 1, R = 50Ω or 27Ω (Note 2) Figure 1, R = 50Ω or 27Ω VCC / 2 Figure 1, R = 50Ω or 27Ω (Note 2) VIH T_IN, EN_, EN, EN VIL T_IN, EN_, EN, EN IHOT V IIN T_IN, EN_, EN, EN ISC -7V < VOUT < +10V (Note 4) ±25 MAX3040/MAX3041/MAX3042B EN_ = GND Output Leakage (Y_, Z_) when Disabled 3 V 0.2 V V EN_, EN, EN (Note 3) Driver Short-Circuit Output Current V 2.0 SWAP Driver Input Current 0.2 MAX3043/MAX3044/MAX3045B EN = GND, EN = VCC 0.8 V ±200 µA ±1 µA ±250 mA ±1 µA ESD Protection (Y_, Z_) Human Body Model ±10 kV Electrical Fast Transient/Burst Immunity IEC 1000-4-4 ±4 kV No load 1 2 mA 0.002 10 µA SUPPLY CURRENT Supply Current Supply Current in Shutdown Mode 2 ICC MAX3040/MAX3041/MAX3042B EN_ = GND, TA = +25°C ISHDN MAX3043/MAX3044/MAX3045B EN = GND, EN = VCC, TA = +25°C _______________________________________________________________________________________ ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER Maximum Data Rate SYMBOL CONDITIONS fMAX Driver Propagation Delay tPLH tPHL Driver Differential Output Rise-Time/Fall-Time tF tR TYP MAX 250 UNITS kbps 0.7 1.5 0.7 1.5 0.48 0.75 1.33 0.48 0.75 1.33 Figures 2 and 3, R DIFF = 54Ω, C DIFF = 50pF µs Figures 2 and 3, R DIFF = 54Ω, C DIFF = 50pF µs tDSKEW Different chips tSSKEW Same chip tSKEW Figures 2 and 3, R DIFF = 54Ω, C DIFF = 50pF Skew Driver to Driver Driver Differential Output Skew | tPLH - t PHL | MIN ±350 Figures 2 and 3, RDIFF = 54Ω, CDIFF = 50pF ns ±100 ±100 ns MAX3040, Figures 4 and 5, S2 closed, R L = 500Ω, C L = 100pF 2.0 µs Figures 4 and 5, S2 closed, R L = 500Ω, C L = 100pF 2.0 µs MAX3040, Figures 4 and 5, S1 closed, R L = 500Ω, C L = 100pF 2.0 µs tZL(SHDN) Figures 4 and 5, S1 closed, R L = 500Ω, C L = 100pF 2.0 µs Driver Disable Time from Low tLZ Figures 4 and 5, S1 closed, R L = 500Ω, C L = 15pF 500 ns Driver Disable Time from High tHZ Figures 4 and 5, S2 closed, R L = 500Ω, C L = 15pF 500 ns TYP MAX UNITS 70 150 70 150 33 70 133 33 70 133 Driver Enable to Output High Driver Enable from Shutdown to Output High Driver Enable to Output Low Driver Enable from Shutdown to Output Low tZH tZH(SHDN) tZL SWITCHING CHARACTERISTICS—MAX3041/MAX3044 (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER Maximum Data Rate Driver Propagation Delay Driver Differential Output Rise-Time/Fall-Time SYMBOL CONDITIONS fMAX tPLH tPHL tF tR 2.5 Figures 2 and 3, RDIFF = 54Ω, C DIFF = 50pF Figures 2 and 3, RDIFF = 54Ω, C DIFF = 50pF Driver Enable to Output High Mbps ns ns ±52 tDSKEW Different chips tSSKEW Same chip tSKEW Figures 2 and 3, RDIFF = 54Ω, C DIFF = 50pF ±15 ns MAX3041, Figures 4 and 5, S2 closed, RL = 500Ω, C L = 100pF 400 ns Skew Driver to Driver Driver Differential Output Skew | tPLH - t PHL | MIN tZH Figures 2 and 3, RDIFF = 54Ω, CDIFF = 50pF ±15 ns _______________________________________________________________________________________ 3 MAX3040–MAX3045 SWITCHING CHARACTERISTICS—MAX3040/MAX3043 MAX3040–MAX3045 ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters SWITCHING CHARACTERISTICS—MAX3041/MAX3044 (continued) (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER MAX UNITS Figures 4 and 5, S2 closed, RL = 500Ω, C L = 100pF 400 ns MAX3041, Figures 4 and 5, S1 closed, RL = 500Ω, C L = 100pF 400 ns tZL(SHDN) Figures 4 and 5, S1 closed, RL = 500Ω, C L = 100pF 400 ns Driver Disable Time from Low tLZ Figures 4 and 5, S1 closed, RL = 500Ω, C L = 15pF 500 ns Driver Disable Time from High tHZ Figures 4 and 5, S2 closed, RL = 500Ω, C L = 15pF 500 ns TYP MAX UNITS 23 40 23 40 Driver Enable from Shutdown to Output High Driver Enable to Output Low Driver Enable from Shutdown to Output Low SYMBOL tZH(SHDN) tZL CONDITIONS MIN TYP SWITCHING CHARACTERISTICS—MAX3042B/MAX3045B (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER Maximum Data Rate Driver Propagation Delay Driver Differential Output Rise-Time/Fall-Time SYMBOL CONDITIONS fMAX tPLH tPHL tF tR MIN 20 Figures 2 and 3, RDIFF = 54Ω, C DIFF = 50pF Mbps 17 Figures 2 and 3, RDIFF = 54Ω, C DIFF = 50pF 17 Figures 2 and 3, R DIFF = 54Ω, CDIFF = 50pF ns ns ±8 tDSKEW Different chips tSSKEW Same chip tSKEW Figures 2 and 3, RDIFF = 54Ω, C DIFF = 50pF ±8 ns MAX3042B, Figures 4 and 5, S2 closed, RL = 500Ω, C L = 100pF 300 ns Figures 4 and 5, S2 closed, RL = 500Ω, C L = 100pF 300 ns MAX3042B, Figures 4 and 5, S1 closed, RL = 500Ω, C L = 100pF 300 ns tZL(SHDN) Figures 4 and 5, S1 closed, RL = 500Ω, C L = 100pF 300 ns Driver Disable Time from Low tLZ Figures 4 and 5, S1 closed, RL = 500Ω, C L = 15pF 400 ns Driver Disable Time from High tHZ Figures 4 and 5, S2 closed, RL = 500Ω, C L = 15pF 400 ns Skew Driver to Driver Differential Driver Output Skew | t PLH - t PHL | Driver Enable to Output High Driver Enable from Shutdown to Output High Driver Enable to Output Low Driver Enable from Shutdown to Output Low tZH tZH(SHDN) tZL ±8 ns Note 1: All currents into the device are positive; all currents out of the device are negative. All voltages are referenced to device ground unless otherwise noted. Note 2: ∆VOD and ∆VOC are the changes in VOD and VOC, respectively, when the transmitter input changes state. Note 3: This input current level is for the hot-swap enable (EN_, EN, EN) inputs and is present until the first transition only. After the first transition the input reverts to a standard high-impedance CMOS input with input current IIN. For the first 20µs the input current may be as high as 1mA. During this period the input is disabled. Note 4: Maximum current level applies to peak current just prior to foldback-current limiting. Minimum current level applies during current limiting. 4 _______________________________________________________________________________________ ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters 25 20 15 30 25 20 15 10 40 30 20 10 5 5 0 0 0 0.1 1 10 100 1000 NO LOAD ALL FOUR TRANSMITTERS SWITCHING 50 SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) 0.1 1 10 100 1000 0.1 10,000 1 10 100 1000 10,000 100,000 DATA RATE (kbps) DATA RATE (kbps) DATA RATE (kbps) SUPPLY CURRENT vs. TEMPERATURE OUTPUT CURRENT vs. TRANSMITTER OUTPUT HIGH VOLTAGE OUTPUT CURRENT vs. TRANSMITTER OUTPUT LOW VOLTAGE 1.0 VCC = 4.75V 0.9 MAX3040 toc06 60 60 OUTPUT CURRENT (mA) VCC = 5V 70 MAX3040 toc06 70 OUTPUT CURRENT (mA) VCC = 5.25V 1.1 80 MAX3040 toc04 1.2 50 40 30 20 50 40 30 20 0.8 NO LOAD NO SWITCHING 10 10 0 0 0.7 30 40 50 60 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 70 TEMPERATURE (°C) 0 2 OUTPUT LOW VOLTAGE (V) OUTPUT CURRENT vs. DIFFERENTIAL OUTPUT VOLTAGE 4 6 8 10 OUTPUT LOW VOLTAGE (V) TRANSMITTER DIFFERENTIAL OUTPUT VOLTAGE vs. TEMPERATURE 70 60 50 40 30 20 10 2.55 2.50 MAX3040 toc08 20 MAX3040 toc07 10 OUTPUT CURRENT (mA) 0 DIFFERENTIAL OUTPUT VOLTAGE (V) SUPPLY CURRENT (mA) 30 10 SUPPLY CURRENT (mA) NO LOAD ALL FOUR TRANSMITTERS SWITCHING 35 60 MAX3040 toc02 NO LOAD ALL FOUR TRANSMITTERS SWITCHING 35 40 MAX3040 toc01 45 40 MAX3042B/MAX3045B SUPPLY CURRENT vs. DATA RATE MAX3041/MAX3044 SUPPLY CURRENT vs. DATA RATE MAX3040 toc03 MAX3040/MAX3043 SUPPLY CURRENT vs. DATA RATE RDIFF = 54Ω 2.45 2.40 2.35 2.30 2.25 2.20 2.15 0 2.10 0 1 2 3 4 DIFFERENTIAL OUTPUT VOLTAGE (V) 5 0 10 20 30 40 50 60 70 TEMPERATURE (°C) _______________________________________________________________________________________ 5 MAX3040–MAX3045 Typical Operating Characteristics (VCC = +5V, TA = +25°C, unless otherwise noted.) ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters MAX3040–MAX3045 Pin Description PIN MAX3040/MAX3041/ MAX3042B MAX3043/MAX3044/ MAX3045B NAME 1 1 T1IN 2 2 Y1 Noninverting Transmitter 1 Output 3 3 Z1 Inverting Transmitter 1 Output EN Transmitter Enable High Input. Drive EN high to enable all four transmitters. When EN is low and EN is high, all transmitters are disabled and the part enters a low-power shutdown state. The transmitter outputs are high impedance when disabled. — Transmitter 1 Input Transmitter Enable Input to Control Transmitters 1 and 2. Drive EN12 high to enable transmitters 1 and 2. Drive EN12 low to disable transmitters 1 and 2. The transmitter outputs are high impedance when disabled. The part enters a low-power shutdown state when both EN12 and EN34 are low. 4 — EN12 5 5 Z2 Inverting Transmitter 2 Output 6 6 Y2 Noninverting Transmitter 2 Output 7 7 T2IN Transmitter 2 Input 8 8 GND Ground 9 9 T3IN Transmitter 3 Input 10 10 Y3 Noninverting Transmitter 3 Output 11 11 Z3 Inverting Transmitter 3 Output EN Transmitter Enable Low Input. Drive EN low to enable all four transmitters. When EN is low and EN is high, all transmitters are disabled and the part enters a low-power shutdown state. The transmitter outputs are high impedance when disabled. — 12 6 4 FUNCTION 12 — EN34 Transmitter Enable Input to Control Transmitters 3 and 4. Drive EN34 high to enable transmitters 3 and 4. Drive EN34 low to disable transmitters 3 and 4. The transmitter outputs are high impedance when disabled. The part enters a low-power shutdown state when both EN12 and EN34 are low. 13 13 Z4 Inverting Transmitter 4 Output 14 14 Y4 Noninverting Transmitter 4 Output 15 15 T4IN Transmitter 4 Input 16 16 VCC Positive Supply. Bypass with a 0.1µF capacitor to GND. _______________________________________________________________________________________ ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters The MAX3040–MAX3045 are quad RS-485/RS-422 transmitters. They operate from a single +5V power supply and are designed to give optimum performance when used with the MAX3093E/MAX3095 5V quad RS-485/ RS-422 receivers or MAX3094E/MAX3096 3V quad RS-485/RS-422 receivers. The MAX3040–MAX3045 only need 1mA of operating supply current and consume 2nA when they enter a low-power shutdown mode. The MAX3040–MAX3045 also feature a hot-swap capability allowing line insertion without erroneous data transfer. The MAX3042B/MAX3045B are capable of transferring data up to 20Mbps, the MAX3041/MAX3044 for data rates up to 2.5Mbps, and the MAX3040/MAX3043 for data rates up to 250kbps. All transmitter outputs are protected to ±10kV using the Human Body Model. ESD Test Conditions ESD performance depends on a number of conditions. Contact Maxim for a reliability report that documents test setup, methodology, and results. 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 device through a 1.5kΩ resistor. 3V DI 1.5V 1.5V 0 tPLH tPHL 1/2 VO ±10kV ESD Protection As with all Maxim devices, ESD-protection structures are incorporated on all pins to protect against electrostatic discharges (ESD) encountered during handling and assembly. The MAX3040–MAX3045 transmitter outputs have extra protection against electrostatic discharges found in normal operation. Maxim’s engineers have developed state-of-the-art structures to protect these pins against the application of ±10kV ESD (Human Body Model), without damage. Z VO Y 1/2 VO VO VDIFF 0 -VO VDIFF = V (Y) - V (Z) 90% 90% 10% tR 10% tF tSKEW = | tPLH - tPHL | Figure 3. Driver Propagation Delays Y VCC S1 RL R OUTPUT UNDER TEST VOD CL VOC S2 R Figure 4. Driver Enable/Disable Timing Test Load Z Figure 1. Driver DC Test Circuit 3V DE 1.5V 1.5V 0 5V DE tZL(SHDN), tZL tLZ Y, Z DI Y VOD Z RDIFF CDIFF VOL 2.5V OUTPUT NORMALLY LOW OUTPUT NORMALLY HIGH Y, Z VOH -0.5V 2.5V 0 tZH(SHDN), tZH Figure 2. Driver Timing Test Circuit VOL +0.5V tHZ Figure 5. Driver Enable and Disable Times _______________________________________________________________________________________ 7 MAX3040–MAX3045 Detailed Description MAX3040–MAX3045 ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters Machine Model The Machine Model for ESD testing uses a 200pF storage capacitor and zero-discharge resistance. It mimics the stress caused by handling during manufacturing and assembly. Of course, all pins (not just RS-485 inputs) require this protection during manufacturing. Therefore, the Machine Model is less relevant to the I/O ports than are the Human Body Model. ±4kV Electrical Fast Transient/Burst Testing (IEC 1000-4-4) IEC 1000-4-4 Electrical Fast Transient/Burst (EFT/B) is an immunity test for the evaluation of electrical and electronic systems during operating conditions. The test was adapted for evaluation of integrated circuits with power applied. Repetitive fast transients with severe pulsed EMI were applied to signal and control ports. Over 15,000 distinct discharges per minute are sent to each interface port of the IC or equipment under test (EUT) simultaneously with a minimum test duration time of one minute. This simulates stress due to displacement current from electrical transients on AC mains, or other telecommunication lines in close proximity. Short rise times and very specific repetition rates are essential to the validity of the test. Stress placed on the EUT is severe. In addition to the controlled individual discharges placed on the EUT, extraneous noise and ringing on the transmission line can multiply the number of discharges as well as increase the magnitude of each discharge. All cabling was left unterminated to simulate worst-case reflections. The MAX3040–MAX3045 were setup as specified in IEC 1000-4-4 and the Typical Operating Circuit of this data sheet. The amplitude, pulse rise time, pulse duration, pulse repetition period, burst duration, and burst period (Figure 8) of the burst generator were all verified with a digital oscilloscope according to the specifications in IEC 1000-4-4 sections 6.1.1 and 6.1.2. A simplified diagram of the EFT/B generator is shown in Figure 7. The burst stresses were applied to Y1–Y4 and Z1–Z4 simultaneously. IEC 1000-4-4 provides several levels of test severity (see Table 1). The MAX3040–MAX3045 pass the 4000V stress, a special category “X” beyond the highest level for severe (transient) industrial environments for telecommunication lines. 8 RC 1MΩ CHARGE-CURRENT LIMIT RESISTOR HIGHVOLTAGE DC SOURCE Cs 100pF RD 1.5kΩ DISCHARGE RESISTANCE DEVICE UNDER TEST STORAGE CAPACITOR Figure 6a. Human Body ESD Test Model IP 100% 90% Ir PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE) AMPERES 36.8% 10% 0 0 tRL TIME tDL CURRENT WAVEFORM Figure 6b. Human Body Model Current Waveform Table 1. Test Severity Levels for Communication Lines ON I/O, SIGNAL, DATA AND CONTROL LEVEL PORTS PEAK VOLTAGE INDUSTRIAL ELECTROMAGNETIC ENVIROMENT EFT REPETITION RATE (kHz) 1 250 5 Well protected 2 500 5 Protected 3 1000 5 Typical 4 2000 5 Severe X 4000 5 MAX3040–MAX3045 _______________________________________________________________________________________ ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters SPARK GAP RC The stresses are applied while the MAX3040–MAX3045 are powered up. Test results are reported as: 1) Normal performance within the specification limits. 2) Temporary degradation or loss of function or performance which is self-recoverable. 3) Temporary degradation, loss of function or performance requiring operator intervention, such as system reset. 4) Degradation or loss of function not recoverable due to damage. The MAX3040–MAX3045 meets classification 2 listed above. Additionally, the MAX3040–MAX3045 will not latchup during the IEC burst stress events. U RM CD MAX3040–MAX3045 IEC 1000-4-4 Burst/Electrical Fast Transient Test Levels (For Communication Lines) COAXIAL OUTPUT 50Ω RS CE U = HIGH-VOLTAGE SOURCE RC = CHARGING RESISTOR CE = ENERGY STORAGE CAPACITOR RS = PULSE DURATION SHAPING RESISTOR RM = IMPEDANCE MATCHING RESISTOR CD = DC BLOCKING CAPACITOR Figure 7. Simplified Circuit Diagram of a Fast Transient/Burst Generator Hot-Swap Capability Hot-Swap Inputs When circuit boards are plugged into a “hot” backplane, there can be disturbances to the differential signal levels that could be detected by receivers connected to the transmission line. This erroneous data could cause data errors to an RS-485/RS-422 system. To avoid this, the MAX3040–MAX3045 have hot-swap capable inputs. When a circuit board is plugged into a “hot” backplane there is an interval during which the processor is going through its power-up sequence. During this time, the processor’s output drivers are high impedance and will be unable to drive the enable inputs of the MAX3040–MAX3045 (EN, EN, EN_) to defined logic levels. Leakage currents from these high impedance drivers, of as much as 10µA, could cause the enable inputs of the MAX3040–MAX3045 to drift high or low. Additionally, parasitic capacitance of the circuit board could cause capacitive coupling of the enable inputs to either GND or V CC . These factors could cause the enable inputs of the MAX3040–MAX3045 to drift to levels that may enable the transmitter outputs (Y_ and Z_). To avoid this problem, the hot-swap input provides a method of holding the enable inputs of the MAX3040–MAX3045 in the disabled state as V CC ramps up. This hot-swap input is able to overcome the leakage currents and parasitic capacitances that may pull the enable inputs to the enabled state. Hot-Swap Input Circuitry In the MAX3040–MAX3045 the enable inputs feature hot-swap capability. At the input there are two NMOS PULSE REPETITION PERIOD (DEPENDS ON THE TEST VOLTAGE LEVER, IN CONFORMITY WITH THE VALUES INDICATED IN 6.1.2). BURST 15ms BURST DURATION BURST PERIOD 300ms Figure 8. General Graph of a Fast Transient Burst devices, Q1 and Q2 (Figure 9). When VCC is ramping up from 0, an internal 10µs timer turns on Q2 and sets the SR latch, which also turns on Q1. Transistors Q2, a 700µA current sink, and Q1, an 85µA current sink, pull EN to GND through a 5.6kΩ resistor. Q2 is designed to pull the EN input to the disabled state against an external parasitic capacitance of up to 100pF that is trying to enable the EN input. After 10µs, the timer turns Q2 off and Q1 remains on, holding the EN input low against three-state output leakages that might enable EN. Q1 remains on until an external source overcomes the _______________________________________________________________________________________ 9 MAX3040–MAX3045 ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters VCC 10µs TIMER TIMER 5.6kΩ EN (HOT SWAP) EN 85µA Q1 700µA Q2 Figure 9. Simplified Structure of the Driver Enable Pin (EN) required input current. At this time the SR latch resets and Q1 turns off. When Q1 turns off, EN reverts to a standard, high-impedance CMOS input. Whenever VCC drops below 1V, the hot-swap input is reset. The EN12 and EN34 input structures are identical to the EN input. For the EN input, there is a complimentary circuit employing two PMOS devices pulling the EN input to VCC. Hot-Swap Line Transient The circuit of Figure 10 shows a typical offset termination used to guarantee a greater than 200mV offset when a line is not driven. The 50pF represents the minimum parasitic capacitance which would exist in a typical application. In most cases, more capacitance exists in the system and will reduce the magnitude of the glitch. During a “hot-swap” event when the driver is connected to the line and is powered up, the driver must not cause the differential signal to drop below 200mV. Figures 11 and 12 show the results of the MAX3040–MAX3045 during power-up for two different VCC ramp rates (0.1V/µs and 1V/µs). The photos show the VCC ramp, the single-ended signal on each side of the 100Ω termination, the differential signal across the termination, and shows the hot-swap line transient stays above the 200mV RS-485 specification. 10 Operation of Enable Pins The MAX3040–MAX3045 family has two enable-functional versions: The MAX3040/MAX3041/MAX3042B have two transmitter enable inputs EN12 and EN34. EN12 controls the transmitters 1 and 2, and EN34 controls transmitters 3 and 4. EN12 and EN34 are active-high and the part will enter the low-power shutdown mode when both are pulled low. The transmitter outputs are high impedance when disabled (Table 2). The MAX3043/MAX3044/MAX3045B have two transmitter enable inputs EN and EN, which are active-high and active-low, respectively. When EN is logic high or EN is logic low all transmitters are active. When EN is pulled low and EN is driven high, all transmitters are disabled and the part enters the low-power shutdown mode. The transmitter outputs are high impedance when disabled (Table 3). Applications Information Typical Applications The MAX3040–MAX3045 offer optimum performance when used with the MAX3093E/MAX3095 5V quad receivers or MAX3094E/MAX3096 3V quad differential line receivers. Figure 13 shows a typical RS-485 connection for transmitting and receiving data and Figure 14 shows a typical multi-point connection. ______________________________________________________________________________________ ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters Table 3. Function Table for MAX3043/ MAX3044/MAX3045B (Each Pair of Transmitters) (All Transmitters) OUTPUTS INPUT EN_ Y_ H H L L H L H L High-Z H = Logic High L = Logic Low High-Z X = Don’t Care High-Z = High Impedance VCC EN EN H H X Z_ H X INPUT OUTPUTS Y Z H L H L H X L H X L H L L X L L H X L H High-Z High-Z H = Logic High X = Don’t Care L = Logic Low High-Z = High Impedance 5V 1kΩ Y TIN (VCC OR GND) 0.1kΩ VCC 2V/div Y 200mV/div Z 200mV/div 50pF Z 1kΩ Y-Z (20mV/div) 238mV Figure 10. Differential Power-Up Glitch (Hot Swap) Figure 11. Differential Power-Up Glitch (0.1V/µs) VCC 2V/div Y 50mV/div Z 50mV/div Y-Z (5mV/div) 238mV 1µs/div Figure 12. Differential Power-Up Glitch (1V/µs) ______________________________________________________________________________________ 11 MAX3040–MAX3045 Table 2. Function Table for MAX3040/ MAX3041/MAX3042B MAX3040–MAX3045 ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters MAX3043–MAX3045 MAX3095 T1IN D1 RT R1 R1OUT T2IN D2 RT R2 R2OUT T3IN D3 RT R3 R3OUT T4IN D4 RT R4 R4OUT EN EN G G VCC GND VCC GND Figure 13. Typical Connection of a Quad Transmitter and a Quad Receiver as a Pair Typical Multiple-Point Connection Figure 14 shows a typical multiple-point connection for the MAX3040–MAX3045 with the MAX3095. Because of the high frequencies and the distances involved, high attention must be paid to transmission-line effects while using termination resistors. A terminating resistor (RT) is simply a resistor that should be placed at the extreme ends of the cable to match the characteristic impedance of the cable. When the termination resistance is not the same value as the characteristic 12 impedance of the cable, reflections will occur as the signal is traveling down the cable. Although some reflections are inevitable due to the cable and resistor tolerances, large mismatches can cause significant reflections resulting in errors in the data. With this in mind, it is very important to match the terminating resistance and the characteristic impedance as closely as possible. As a general rule in a multi-drop system, termination resistors should always be placed at both ends of the cable. ______________________________________________________________________________________ ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters 1/4 MAX3040–MAX3045 RT RT 1/4 MAX3095 1/4 MAX3095 UP TO 32 RS-485 UNIT LOADS 1/4 MAX3040–MAX3045 1/4 MAX3040–MAX3045 1/4 MAX3095 1/4 MAX3095 Figure 12. Typical Connection for Multiple-Point RS-485 Bus Ordering Information (continued) PART MAX3041CUE TEMP RANGE 0°C to +70°C PIN-PACKAGE 16 TSSOP DATA RATE PART 2.5Mbps MAX3045BCUE 0°C to +70°C 16 TSSOP 20Mbps 0°C to +70°C 16 Narrow SO 20Mbps 0°C to +70°C TEMP RANGE PIN-PACKAGE DATA RATE 0°C to +70°C 16 Narrow SO 2.5Mbps MAX3045BCSE MAX3041CWE 0°C to +70°C 16 Wide SO 2.5Mbps MAX3045BCWE 16 Wide SO 20Mbps MAX3041EUE -40°C to +85°C 16 TSSOP 2.5Mbps MAX3045BEUE -40°C to +85°C 16 TSSOP 20Mbps MAX3041ESE -40°C to +85°C 16 Narrow SO 2.5Mbps MAX3045BESE -40°C to +85°C 16 Narrow SO 20Mbps MAX3041EWE -40°C to +85°C MAX3045BEWE -40°C to +85°C 16 Wide SO 20Mbps MAX3041CSE 16 Wide SO 2.5Mbps MAX3042BCUE 0°C to +70°C 16 TSSOP 20Mbps MAX3042BCSE 0°C to +70°C 16 Narrow SO 20Mbps MAX3042BCWE 0°C to +70°C Pin Configurations (continued) 16 Wide SO 20Mbps MAX3042BEUE -40°C to +85°C 16 TSSOP 20Mbps MAX3042BESE -40°C to +85°C 16 Narrow SO 20Mbps T1IN 1 16 VCC MAX3042BEWE -40°C to +85°C 15 T4IN TOP VIEW 16 Wide SO 20Mbps Y1 2 MAX3043CUE 0°C to +70°C 16 TSSOP 250kbps Z1 3 MAX3043CSE 0°C to +70°C 16 Narrow SO 250kbps EN 4 MAX3043EWE 0°C to +70°C 16 Wide SO 250kbps Z2 5 MAX3043EUE -40°C to +85°C 16 TSSOP 250kbps Y2 6 11 Z3 MAX3043ESE -40°C to +85°C 16 Narrow SO 250kbps T2IN 7 10 Y3 MAX3043EWE -40°C to +85°C 16 Wide SO 250kbps GND 8 9 MAX3044CUE 0°C to +70°C 16 TSSOP 2.5Mbps MAX3044CSE 0°C to +70°C 16 Narrow SO 2.5Mbps MAX3044CWE 0°C to +70°C 16 Wide SO 2.5Mbps MAX3044EUE -40°C to +85°C 16 TSSOP 2.5Mbps MAX3044ESE -40°C to +85°C 16 Narrow SO 2.5Mbps MAX3044EWE -40°C to +85°C 16 Wide SO 2.5Mbps 14 Y4 MAX3043 MAX3044 MAX3045B 13 Z4 12 EN T3IN 16 TSSOP/SO Chip Information TRANSISTOR COUNT: 545 PROCESS: CMOS ______________________________________________________________________________________ 13 MAX3040–MAX3045 1/4 MAX3040–MAX3045 MAX3040–MAX3045 ±10kV ESD-Protected, Quad 5V RS-485/422 Transmitters Ordering Information (continued) PART TEMP. RANGE MAX3041CUE 0°C to +70°C PIN-PACKAGE 16 TSSOP DATA RATE DATA RATE PART TEMP. RANGE 2.5Mbps MAX3044CUE 0°C to +70°C 16 TSSOP 2.5Mbps 0°C to +70°C 16 Narrow SO 2.5Mbps PIN-PACKAGE MAX3041CSE 0°C to +70°C 16 Narrow SO 2.5Mbps MAX3044CSE MAX3041CWE 0°C to +70°C 16 Wide SO 2.5Mbps MAX3044CWE 0°C to +70°C 16 Wide SO 2.5Mbps 2.5Mbps MAX3044EUE -40°C to +85°C 16 TSSOP 2.5Mbps -40°C to +85°C 16 Narrow SO 2.5Mbps -40°C to +85°C MAX3041EUE -40°C to +85°C 16 TSSOP MAX3041ESE -40°C to +85°C 16 Narrow SO 2.5Mbps MAX3044ESE MAX3041EWE -40°C to +85°C 16 Wide SO 2.5Mbps MAX3044EWE 16 Wide SO 2.5Mbps 20Mbps MAX3045BCUE 0°C to +70°C 16 TSSOP 20Mbps 0°C to +70°C 16 Narrow SO 20Mbps 0°C to +70°C MAX3042BCUE 0°C to +70°C 16 TSSOP MAX3042BCSE 0°C to +70°C 16 Narrow SO 20Mbps MAX3045BCSE MAX3042BCWE 0°C to +70°C 16 Wide SO 20Mbps MAX3045BCWE 16 Wide SO 20Mbps 20Mbps MAX3045BEUE -40°C to +85°C 16 TSSOP 20Mbps 16 Narrow SO 20Mbps 16 Wide SO 20Mbps MAX3042BEUE -40°C to +85°C 16 TSSOP MAX3042BESE -40°C to +85°C 16 Narrow SO 20Mbps MAX3045BESE -40°C to +85°C MAX3042BEWE -40°C to +85°C 16 Wide SO 20Mbps MAX3045BEWE -40°C to +85°C MAX3043CUE 0°C to +70°C 16 TSSOP 250kbps MAX3043CSE 0°C to +70°C 16 Narrow SO 250kbps MAX3043EWE 0°C to +70°C 16 Wide SO 250kbps MAX3043EUE -40°C to +85°C 16 TSSOP 250kbps MAX3043ESE -40°C to +85°C 16 Narrow SO 250kbps MAX3043EWE -40°C to +85°C 16 Wide SO 250kbps Pin Configurations (continued) TOP VIEW T1IN 1 16 VCC Y1 2 15 T4IN Z1 3 14 Y4 EN 4 Z2 5 MAX3043 MAX3044 MAX3045B 13 Z4 12 EN Y2 6 11 Z3 T2IN 7 10 Y3 GND 8 9 16 TSSOP/SO 14 ______________________________________________________________________________________ T3IN ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters SOICW.EPS 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. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX3040–MAX3045 Package Information (continued)