19-0144; Rev. 0; 9/93 Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers General Description The MAX562 is designed specifically for notebook and palmtop computers that need to transfer data quickly. It runs at data rates up to 230kbps, and has a guaran- teed 4V/us slew rate. This device meets the new EIA/TIA-562 standard that guarantees compatibility with RS-232 interfaces. The MAX562 has low-power shutdown and keep-awake modes. In keep-awake mode, the transmitters are dis- abled but all receivers are active, allowing unidirection- al communication. In shutdown mode, the entire chip is disabled and all outputs are in a high-impedance state. The MAX562 is available in a standard 28-pin SO pack- age, and in a smaller footprint shrink small-outline package (SSOP). Applications Palmtop, Notebook, and Subnotebook Computers Peripherals Battery-Powered Equipment Typical Operating Circuit MA AAILM Features # 230kbps Data Rate, LapLink Compatible Operates from a 2.7V to 5.25V Supply @ Designed for ElIA/TIA-562 and EIA/TIA-232 Applications @ Guaranteed 4.0V/1s Slew Rate 3 Drivers, 5 Receivers Flow Through Pinout @ Low-Power Shutdown and Keep-Awake Modes @ Low-Cost, Surface-Mount External Capacitors Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX562CWl OC to +70C 28 SO MAX562CAI OC to +70C 28 SSOP MAX562C/D OC to +70C Dice* MAX562EWI -40C to +85C 28 SO MAX562EAI -40C to +85C 28 SSOP 0.33pF 33uF 3 0S AAAXAAA 427V10 AGE [cis]. MAX562 45.25V sf oi Cia Cree Cie Ln r Voc L V+ | INPUT >30.33UF 06 OOUBLER/TRIPLER 63 a 0.88pF = Bee |e voutase vf = O.33yF-T_24 ca. INVERTER cask oxaue Tin as fie By Tour EWNTIA CMOS 2 Tay yy >> U7 tour b 862 INPUTS OUTPUTS Tay > -_li}>_ Hb Tour Rtour <fi 23 ae Ri 5k R2gut + 2 ts 22 RON = EIA/TIA cmos / Raour + i R3 21 R3in 562 OUTPUTS zm INPUTS Raut <2 hs} p20 fat q 5k RSgur <| ofS By EN 14 sk P15 SHON * Contact factory for dice specifications. Pin Configuration TOP VIEW Veo lt] * 28] V+ C1A+ [2 | 27| GND C1B+ 3 26 V- c1B- [4 | 25] C2+ Rigut | 6 23] Rtn aa 22| R2iN r3our [8 21] ay RAput | 9] 20! Rain RS our [19 19) R5in Tin [14] 18] Tout Tain [12] H7| T2our T3in [19 1.6} T3cur EN [14 15] SHDN SO/SSOP LapLink is a registered trademark of Traveling Software, Inc. MAXIMA Call toll free 1-800-998-8800 for free samples or literature. c9SXVW Maxim integrated Products 2-175MAX562 Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers ABSOLUTE MAXIMUM RATINGS Input Voltages Tay EN, SHDN oe cccccccceeee Ray evsvvesseeesesssenevseveassseresssenteee Output Voltages decteeeees -0.3V to (V+ + 0.3V) dete tceueeetiaeeeeeeeees -0.3V to +6V Short-Circuit Duration (Voc - 0.3V) to +6V Tout tO GND oc cece eccentrics Continuous Rout to GND, Vec ceteeeeseteses -BV to (V+ + 0.3V) Continuous Power Dissipation (T, = +70C) SO (derate 12.50mW/C above +70C) des tctetteseeaes (V- - 0.3V) to +6V SSOP (derate 9.52mW/C above +70C) Operating Temperature Ranges: sete teaeee -0.3V to (Veg + 0.3V) MAX562C_ _.. caesesesuetecsesetesaceesensteteenes +25V MAX562E_ oo... eee pesos +0.3V to -6V -0.3V to (Vee + 0.3V) dene caeeeeeenenennecteeetsaeereees +15V Lead Temperature (soldering, 10sec) Continuous . OPC to +70C .. ~40C to +85C 65C to +160C 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 canditions 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 (Voce = 2.7V to 5.25V, CIA = CIB = C2 = C4 = 0.33pF, C3 = 0.68uF, Ty = Try tO Tax, unless otherwise noted.) PARAMETER | CONDITIONS | MIN TYP MAX UNITS EIA/TIA-562 TRANSMITTERS Output Voltage Swing All transmitter outputs loaded with 3kQ to GND 3.7 +45 +6.0 Vv an Vcc = 2.7V to 3.6V 0.6 Input Logic Threshold Lo Tin, EN, SHON V purnogie ine i IN: Voc = 5.0V +5%, -10% 08 . aaKG Vec = 2.7V to 3.6V 1.8 Input Logic Threshold High Tin, EN, SHON Vv purnogie ime: 9 IN Voc = 5.0V +5%, -10% 3.0 Output Leakage Current +10 pA Output Resistance Veco = V+ = V- = OV, VouT = +2V 300 Q Output Short-Circuit Current Vout = OV +60 mA EIA/TIA-562 RECEIVERS Input Voltage Operating Range +25 Vv Input Threshold Low 0.8 V Input Threshold High 2.4 Vv Input Hysteresis No hysteresis when SHON = OV 0.3 v Input Resistance -15V < Vin < 15V 3 5 7 kQ Output Voltage Low lout = 1.6mA 0.4 v Output Voltage High lout = -1.0mA Vec 0.5 Vv Output Leakage Current EN = GND, OV < Rout $ Vcc 0.05 +10 pA POWER SUPPLY Operating Supply Voltage 27 5.25 V No load 20 33 Vec Power-Supply C t Vcc = 3.3V A ce upPly wurren ce All outputs loaded 3kQ 24 m Shutdown Suoply Current with _ a _ 6 Receivers Active N = Voc, SHDN = GND, Ta = +25C 45 130 pA Shutdown Supply Current SHDN = EN = GND, Ta = +25C 1 50 pA 2-176 MAXIAAComplete 230kbps, 2.7V to 5.25V Serial interface for Notebook Computers AC CHARACTERISTICS = PARAMETER CONDITIONS MIN TYP MAX UNITS > Data Rate 1000pF II 3kQ load each transmitter output, 230.4 2800 kbits/sec s 150pF load each receiver output CL = 50pF to 2500pF, QO Transmitter Slew Rate Ry = 3kQ to 7kQ. Measured from +3V to -3V, or 4 6 30 Vius 0) BV to +3V N RL = 3kQ measured CL = 2500pF 0.22 3.1 Transmitter Rise/Fall Time from +3,3V to -3.3V ps or -3.3V to +3.3V CL = 1000pF 0.22 21 , 2500pF Il 3kQ load tPHLT 900 = 1700 Transmitter Propagation Dela ns Fansmilter rropagal Y | Figure 4 (PLHT 1000 1700 Transmitter-Output Enable Time teT 100 ys Transmitter-Output Disable Time | Figure 3 toT 600 ns Receiver Propagation Delay, CL = 150pF, 'PHLR 100 250 ns Normal Operation SHDN = VCC Figure 2 teLuA 250 500 Receiver Propagation Delay, Stan ae 'PHLS 3000 4000 ns Keep-Awake Mode Figure 2 tPLHS 2000 3000 Receiver-Output Enabie Time Figure 4 tER 100 250 ns Receiver-Output Disable Time Figure 4 tor 250 500 ns MAXLM 2-177MAX562 Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers Typical Operating Characteristics (Veg = 3.3V, CIA = C1B = C2 = C4 = 0.33yF, C3 = 0.68uF, Ta=+25C, unless otherwise noted.) TRANSMITTER SLEW RATE TRANSMITTER OUTPUT VOLTAGE TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE vs. TEMPERATURE vs. LOAD CAPACITANCE, TO 231kbps ALL OUTPUTS LOADED = _ourt = 3kQ 1 CL = = I z 2 z= LOADED 3k NC S 5 = E 2 ALL TRANSMITTERS LOADED 3k 2 & 3 a 2 i 5 E E = = : : = & |QUT- tooo 2000 3000 4000-5000 * a9 0 40 80 > yo00 2000 3000:4000 5000 C.(PF) TEMPERATURE (C) Cr (oF) SUPPLY CURRENT SUPPLY CURRENT SUPPLY CURRENT vs. SUPPLY VOLTAGE vs. TEMPERATURE vs. TRANSMITTER DATA RATE 38 55 TRANSMITTERS 36 50 Veo =42.7V ~ * ~ 8 2 5 30 ALL TRANSMITTERS LOADED 3k. a > > > % z z 2 = 2 OUTPUTS LOADED a 2 9% a 30 3kQ II 24 1 OUTPUT LOADED i 25 30 35 40 45 50 55 20 0 40 80 0. 50. 100 150 200 250 Vec (V) TEMPERATURE (C) DATA RATE (kbps) SUPPLY CURRENT vs. TEMPERATURE 60 -1 SHON =0, EN = | ALL TRANSMITTERS LOADED 3kQ 55 s | = z A 3 45 Voc = +3.3V Ls x LL a | Aiea ope a -40 0 40 80 TEMPERATURE (C) 2-178 MAXIComplete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers Pin Description = PIN NAME FUNCTION = 28 V+ Positive charge-pump output, typically 5.8V QO 2,5 C1A+, CIA- Terminais for positive charge-pump capacitor 2 3,4 C1B+, C1B- Terminals for positive charge-pump capacitor 6, 7, 8,9, 10 R_out TTL/CMOS Receiver Outputs. 11, 12, 13 TIN TTL/CMOS Driver inputs 14 EN Receiver Enable, see Shutdown and Enable Control section. 15 SHON Shutdown Control, see Shutdown and Enable Contro/ section. 16, 17, 18 Tout EIA/TIA-562 Driver Outputs 19, 20, 21, 22, 23 Rin EIA/TIA-562 Receiver Inputs 24, 25 C2+, C2- Terminals for negative charge-pump capacitor 26 V- Negative charge-pump output, typically -5,.2V 27 GND Ground 1 Veo +2.7V to +5.25V Supply Voltage Figure 1. Transmitter Propagation Delay Timing Figure 2, Receiver Propagation Delay Timing MAXLAA 2-179MAX562 Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers TRANSMITTER OUTPUTS A. TIMING DIAGRAM 10R0 3k SOpF 8. TEST CIRCUIT = = Vow -1V, Vo +1.6V Rout ik RLIN O A. TEST CIRCUIT , 150pF t En pur oy [1 nv Pt HE OUTPUT ENABLE TIME (ter) ' RECEIVER ' OUTPUTS ' B. ENABLE TIMING +3V EN ENinpur4, wl a OUTPUT DISABLE TIME (top) Vou <--- Voy -0.5V RECEIVER ' OUTPUTS 1 <= Voy 40.5V Vor C. DISABLE TIMING Figure 3. Transmitter-Output Disable Timing Detailed Description The MAX562 has three sections: the charge-pump voltage converter, the drivers (transmitters), and the receivers. Charge-Pump Voltage Converter The charge-pump voltage converter is used to produce a positive and a negative supply to drive the transmitters. The positive voltage (V+) is generated by a regulated charge pump working as either a doubler or a tripler (depending on the Voc level) and using capacitors C1A, C1B and C3 (see Typical Operating Circuit). The negative voltage (V-) derives from V+ using a simple charge-pump inverter that employs capacitors C2 and C4. These charge-pump converters are regulated to give output voltages of +5.8V and -5.2V. Having regulated supplies generated on-chip makes the MAX562's performance insen- sitive to variations in Vcc from 2.7V to 5.25V, transmitter load- ing changes, and operating temperature changes. When SHDN is low, the charge pumps are disabled, V+ is internally connected to Vac, and V- is internally connected to GND. 2-160 Figure 4. Receiver-Output Enable and Disable Timing EIA/TIA-562 Drivers The driver output voltage is guaranteed to meet the +3.7V EIA/TIA-562 specification over the full range of operating temperatures and voltages, when each transmitter is loaded with up to 3kQ and operated up to 230kbps (see Typical Operating Characteristics). The typical driver out- put voltage swing exceeds +4V with a 3kQ load on all transmitter outputs. The open-circuit output voltage swing is typically from (V+ - 0.7V) to (V- + 0.7V). Output swing is not significantly dependent on Vcc since the charge pumps are regulated. Input thresholds are CMOS and TTL compatible. Connect unused inputs to Voc or to GND. When SHDN is low, the driver outputs are off and their leak- age currents are less than 10uA, even if the transmitter outputs are back-driven between -7V and +15V. Taking SHDN low does not disable the receivers. When SHON and EN are both low, the entire chip is disabled and all outputs are high impedance. Power consumption is lowest in this condition. Exiting shutdown takes about 100ps, but depends on Voc. Figure 5 shows MNAXINAComplete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers =422V Voc =42.7V V = +3.3V Voc = +5.0V VOLTS (V) 0 100 200 300 TIME (ns) Figure 5. Time for Transmitters to Exit Shutdown the MAX562 transmitter outputs when SHDN rises. Two transmitter outputs are shown going to opposite EIA/TIA- 562 levels (one transmitter input is high, the other is low). Each transmitter is loaded with 3kQ in parallel with 2500pF. The transmitter outputs are well behaved, with no ringing or undesirable transients as they come out of shutdown. Driving Multiple Receivers Each transmitter is designed to drive a single receiver. Transmitters can be paralleled to drive multiple receivers. EIA/TIA-562 Receivers All 5 receivers are identical and accept EIA/TIA-562 or EIA/TIA-232 signals. The CMOS receiver outputs swing between Vcc and GND. They are inverting, maintaining compatibility with the driver outputs. Table 1. MAX562 Control Pin Configurations The guaranteed 0.8V and 2.4V receiver input thresh- olds are significantly tighter than the +3.0V thresholds required by the EIA/TIA-562 specification. This allows the receiver inputs to respond to TTL/CMOS logic lev- els as well as ElA/TIA-562/232 levels. Also, the MAX562's guaranteed 0.8V lower threshold ensures that receivers shorted to ground will have a logic 1 out- put. The 5kQ input resistance to ground ensures that a receiver with its input left open will also have a logic 1 output. The receiver inputs have approximately 0.3V hysteresis when SHDN is high. This provides clean output transi- tions, even with slowly moving input signals with mod- erate noise and ringing. The receivers are active when EN is high. When EN is low, the receiver outputs are high impedance. This allows wire-OR connection of two EIA/TIA-562 ports (or ports of different types) at the UART. The receivers are always active,when EN is high, irre- spective of SHDN's state. When SHDN is high, the receivers have hysteresis and experience the shortest propagation delays (typically 100ns falling, 250ns ris- ing). When SHON is low, the receivers have longer propagation delays (typically 3ys falling, 2us rising) and have no hysteresis. The receiver outputs are not valid for 50us after SHON goes low. Shutdown and Enable Control SHDN and EN determine the operation of the MAX562 as shown in Table 1. Applications Information Capacitor Selection The capacitor type is not critical for proper MAX562 operation. Any low cost ceramic capacitor (e.g., Z5U, Y5V) is acceptable for operating at room temperature, SHON EN OPERATION, | TRANSMITTERS | RECEWERS | CimmenT STATUS TYP (A) 0 0 Shutdown High-Z High-Z Tp 0 1 Shutdown High-Z Active 45 1 0 Normal Operation Active High-Z 24m 1 1 Normal Operation Active Active 24m * Active, but with reduced performance (see E/A/TIA-562 Receivers section). This is keep-awake" mode. MAALM c9SXVUWN 2-181: : Complete 230kbps, 2.7V to 5.25V Serial Interface for Notebook Computers Table 2. Summary of EIA/TIA-232E/V.28 and EIA/TIA-562 Specifications ELA/TIA-232E/V.28 EIA/TIA-562 PARAMETER CONDITION SPECIFICATION SPECIFICATION Priver Clutput Voltage 5.0V to 15.0V 3.7V to 13.2V eve 3kQ to 7kQ load 1 Level -.0V to -15.0V -3.7V to -13.2V Maximum Output Level No load +25V +13.2V CL = 2500pF Up to 20kbps Up to 20kbps Signal Rate (3kQ < R, < 7kQ) CL = 1000pF Not defined Up to 64kbps and X7R ceramic capacitors are recommended for operation over the full temperature range. Larger capacitors may be used for C2 and C4 (see Typical Operating Circuit) to reduce ripple on the trans- mitter output voltages. Power-Supply Decoupling in applications that are sensitive to power-supply noise, decouple Vec to ground with a capacitor similar in value to that of the C1A and C1B charge-pump capaci- tors. Connect the bypass capacitor as close as possi- ble to the Veg and GND pins. V+ and V- as Power Supplies Asmall amount of power can be drawn from V+ and V-. Excessive loads will cause V+ and V- to fall out of regulation. When V+ or V- are loaded, check for good regulation over the intended operating temperature range. 2-182 Chip Topography T2out T3in SHDN 0.135" _ (3.429mm) *| Substrate connected to V+ Transistor count: 1892 MAAKLAA