19-0380; Rev 0; 3/95 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ The MAX3218 RS-232 transceiver is intended for battery-powered EIA/TIA-232E and V.28/V.24 communications interfaces that need two drivers and two receivers with minimum power consumption from a single lowvoltage supply. It provides a wide +1.8V to +4.25V operating voltage range while maintaining true RS-232 and EIA/TIA-562 voltage levels. The MAX3218 runs from two alkaline, NiCd, or NiMH cells without any form of voltage regulator. A guaranteed 120kbps data rate provides compatibility with popular software for communicating with personal computers. Supply current is reduced to 1µA with Maxim’s new AutoShutdown™ feature. When the MAX3218 does not sense a valid signal level on the receiver inputs, the onboard power-supply and drivers shut down. This occurs if the RS-232 cable is disconnected or if the transmitters of the connected peripheral are turned off. The system turns on again when a valid level is applied to either RS-232 receiver input. As a result, the system saves power without changes to the existing software. Additionally, the MAX3218 can be forced into or out of shutdown, under logic control. While shut down, all receivers can remain active or can be disabled under logic control, permitting a system incorporating the CMOS MAX3218 to monitor external devices while in low-power shutdown. Three-state drivers are provided on both receiver outputs so that multiple receivers, generally of different interface standards, can be on the same bus. The MAX3218 is available in 20-pin DIP and SSOP packages. ________________________Applications ____________________________Features BETTER THAN BIPOLAR! ♦ 1µA Supply Current Using AutoShutdown™ ♦ Operates Directly from Two Alkaline, NiCd or NiMH Cells ♦ +1.8V to +4.25V Single-Supply Voltage Range ♦ 120kbps Data Rate Guaranteed ♦ Low-Cost Surface-Mount Components ♦ Meets EIA/TIA-232E Specifications ♦ Three-State Receiver Outputs ♦ Flow-Through Pinout ♦ On-Board DC-DC Converters ♦ 20-Pin SSOP and DIP Packages ______________Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX3218CPP MAX3218CAP MAX3218C/D 0°C to +70°C 0°C to +70°C 0°C to +70°C 20 Plastic DIP 20 SSOP Dice† MAX3218EPP -40°C to +85°C 20 Plastic DIP MAX3218EAP -40°C to +85°C 20 SSOP † Contact factory for dice specifications. __________________Pin Configuration Battery-Powered Equipment Subnotebook Computers TOP VIEW LX 1 PDAs Hand-Held Equipment Peripherals Cellular Phones 19 V+ 18 C1+ FORCEON 3 FORCEOFF 4 GND 5 * Patent Pending ™ AutoShutdown is a trademark of Maxim Integrated Products. 20 GND INVALID 2 17 GND MAX3218 16 C1- VCC 6 15 V- T1IN 7 14 T1OUT T2IN 8 13 T2OUT R1OUT 9 12 R1IN R2OUT 10 11 R2IN DIP/SSOP ________________________________________________________________ Maxim Integrated Products Call toll free 1-800-998-8800 for free samples or literature. 1 MAX3218* _______________General Description MAX3218 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ ABSOLUTE MAXIMUM RATINGS Supply Voltages VCC ....................................................................-0.3V to +4.6V V+ .......................................................... (VCC - 0.3V) to +7.5V V- .......................................................................+0.3V to -7.4V VCC to V- ..........................................................................+12V LX ................................................................-0.3V to (1V + V+) Input Voltages T_IN, FORCEON, FORCEOFF ............................ -0.3V to +7V R_IN .................................................................................±25V Output Voltages T_OUT.............................................................................±15V) R_OUT ....................................................-0.3V to (VCC + 0.3V) Short-Circuit Duration, R_OUT, T_OUT to GND ....... Continuous Continuous Power Dissipation (TA = +70°C) Plastic DIP (derate 11.11mW/°C above +70°C) ..........889mW SSOP (derate 8.00mW/°C above +70°C) ..................640mW Operating Temperature Ranges MAX3218C_ P ................................................... 0°C to +70°C MAX3218E_ P ................................................. -40°C to +85°C Storage Temperature Range ........................... -65°C to +150°C Lead Temperature (soldering, 10sec) ........................... +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 (Circuit of Figure 1, VCC = 1.8V to 4.25V, C1 = 0.47µF, C2 = C3 = C4 = 1µF, L1 = 15µH, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.0V, TA = +25°C.) PARAMETER CONDITIONS MIN TYP MAX UNITS 4.25 V DC CHARACTERISTICS Operating Voltage Range 1.8 VCC = 3.0V, TA = +25°C, all R_IN open, Supply Current, AutoShutdown™ FORCEON = GND, FORCEOFF = VCC 1.0 10 µA Supply Current, Shutdown FORCEOFF = GND, TA = +25°C, VCC = 3.0V 1.0 10 µA Supply Current, AutoShutdown™ Disabled FORCEON = FORCEOFF = VCC = 3.0V, no load 2.0 3.0 mA 0.33 x VCC V ±1 µA 0.4 V LOGIC INPUTS AND RECEIVER OUTPUTS Input Logic Threshold Low T_IN, FORCEON, FORCEOFF Input Logic Threshold High T_IN, FORCEON, FORCEOFF Input Leakage Current T_IN, FORCEON = FORCEOFF = 0V or VCC Output Voltage Low R_OUT, IOUT = 1.0mA Output Voltage High R_OUT, IOUT = -0.4mA Output Leakage Current R_OUT, 0V ≤ R_OUT ≤ VCC, FORCEON = FORCEOFF = 0V 0.67 x VCC V 0.001 VCC - 0.25 VCC - 0.08 0.05 V ±10 µA AUTOSHUTDOWN (FORCEON = GND, FORCEOFF = VCC) Positive threshold Negative threshold Receiver Input Thresholds, Transmitters Enabled Figure 4a Receiver Input Thresholds Transmitters Disabled 1µA supply current, Figure 4a INVALID Output Low Voltage IOUT = 1.0mA, -0.3V < R_IN < 0.3V INVALID Output High Voltage IOUT = -0.4mA, |R_IN| > 2.8V 2 2.8 -2.8 -0.3 VCC - 0.25 _______________________________________________________________________________________ V 0.3 V 0.4 V V 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ (Circuit of Figure 1, VCC = 1.8V to 4.25V, C1 = 0.47µF, C2 = C3 = C4 = 1µF, L1 = 15µH, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.0V, TA = +25°C.) PARAMETER CONDITIONS MIN TYP MAX UNITS +25 V EIA/TIA-232E RECEIVER INPUTS Input Voltage Range Input Threshold Low Input Threshold High -25 VCC = 2.0V to 4.25V 0.4 VCC = 1.8V to 4.25V 0.3 V VCC = 1.8V to 4.25V 3.0 VCC = 1.8V to 3.6V 2.8 Input Hysteresis 0.7 Input Resistance -15V < R_IN < 15V 3 5 ±6 V V 7 kΩ EIA/TIA-232E TRANSMITTER OUTPUTS Output Voltage Swing All transmitter outputs loaded with 3kΩ to ground ±5 Output Resistance VCC = 0V, -2V < T_OUT < 2V 300 V Ω Output Short-Circuit Current ±24 ±100 mA TIMING CHARACTERISTICS (Circuit of Figure 1, VCC = 1.8V to 4.25V, C1 = 0.47µF, C2 = C3 = C4 = 1µF, L1 = 15µH, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = 3.0V, TA = +25°C.) PARAMETER SYMBOL Data Rate CONDITIONS MIN TYP 2500pF || 3kΩ load each transmitter, one transmitter switching, 150pF load each receiver 120 235 MAX UNITS kbps Receiver Output Enable Time tER 90 300 ns Receiver Output Disable Time tDR 200 500 ns Transmitter Output Enable Time tET 250 450 µs Transmitter Output Disable Time tDT 500 Receiver Propagation Delay Transmitter Propagation Delay ns tPHLR 150pF load 290 1000 tPLHR 150pF load 260 1000 tPHLT 2500pF || 3kΩ load 1.9 2.7 tPLHT 2500pF || 3kΩ load 1.8 2.7 TA = +25°C, VCC = 3.0V, RL = 3kΩ to 7kΩ, CL = 50pF to 2500pF, measured from +3V to -3V or -3V to +3V Transition Region Slew Rate 3.0 30 ns µs V/µs AUTOSHUTDOWN TIMING Receiver Threshold to Transmitters Enabled tWU Figure 4b 250 µs Receiver Positive or Negative Threshold to INVALID High tINVH Figure 4b 1 µs Receiver Positive or Negative Threshold to INVALID Low tINVL Figure 4b 30 µs _______________________________________________________________________________________ 3 MAX3218 ELECTRICAL CHARACTERISTICS (continued) __________________________________________Typical Operating Characteristics (Circuit of Figure 1, VCC = 1.8V, all transmitter outputs loaded with 3kΩ, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. SUPPLY VOLTAGE TRANSMITTING SUPPLY CURRENT vs. LOAD CAPACITANCE SUPPLY CURRENT (mA) VCC = 2.4V 90 100 240kbps 80 60 120kbps 40 20kbps 20 0kbps MAX3218-02 120 100 SUPPLY CURRENT (mA) 1 TRANSMITTER FULL DATA RATE 1 TRANSMITTER 1/8 DATA RATE RL = 3kΩ + 2500pF MAX3218-01 140 80 235kbps TRANSMITTER 1 OPERATING AT SPECIFIED BIT RATE, TRANSMITTER 2 OPERATING AT 1/16 THAT RATE. 70 60 120kbps 50 40 20kbps 30 0 20 2.4 1.8 3.0 3.6 4.2 1000 0 SUPPLY VOLTAGE (V) 2000 3000 4000 5000 LOAD CAPACITANCE (pF) TIME TO EXIT SHUTDOWN (ONE TRANSMITTER HIGH, ONE TRANSMITTER LOW) FORCEON, FORCEOFF VOH 2V/div T_OUT VCC = 1.8V RL = 3kΩ || 2500pF VOL 100µs/div TRANSMITTER OUTPUT VOLTAGE vs. LOAD CAPACITANCE AT 120kbps SLEW RATE vs. TRANSMITTER CAPACITANCE MAX3218-05 6 10 VOUT+ SLEW RATE (V/µs) 4 2 0 -2 +SLEW 8 -SLEW 6 4 DATA RATE 120kbps, TRANSMITTERS LOADED WITH 3kΩ PLUS INDICATED CAPACITANCE -4 VOUT- 2 -6 0 -8 0 1000 2000 3000 4000 LOAD CAPACITANCE (pF) 4 12 MAX3218-04 8 TRANSMITTER OUTPUT VOLTAGE (V) MAX3218 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ 5000 0 1000 2000 3000 4000 LOAD CAPACITANCE (pF) _______________________________________________________________________________________ 5000 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ PIN NAME FUNCTION 1 LX 2 INVALID 3 FORCEON Drive high when FORCEOFF = high to override automatic circuitry, keeping transmitters on. 4 FORCEOFF Drive low to shut down transmitters and on-board power supply, overriding all automatic circuitry and FORCEON. 5, 17, 20 GND Ground 6 VCC Supply Voltage Input, 1.8V to 4.25V. Bypass to GND with at least 1µF. 7, 8 T1IN, T2IN Transmitter Inputs 9, 10 R1OUT, R2OUT Receiver Outputs 11, 12 R2IN, R1IN 13, 14 T2OUT, T1OUT 15 V- Negative Supply generated on-board 16, 18 C1-, C1+ Terminal for Charge-Pump Capacitor 19 V+ Positive Supply generated on-board Inductor/Diode Connection Point Output of Invalid Signal Detector. Low if invalid RS-232 levels are present on all receiver inputs, otherwise high. Receiver Inputs Transmitter Outputs, swing between V+ and V- _______________Detailed Description The MAX3218 line driver/receiver is intended for battery-powered EIA/TIA-232 and V.28/V.24 communications interfaces that require two drivers and two receivers. The operating voltage extends from 1.8V to 4.25V, yet the device maintains true RS-232 and EIA/TIA-562 transmitter output voltage levels. This wide supply voltage range permits direct operation from a variety of batteries without the need for a voltage regulator. For example, the MAX3218 can be run directly from a single lithium cell or a pair of alkaline cells. It can also be run directly from two NiCd or NiMH cells from full-charge voltage down to the normal 0.9V/cell end-of-life point. The 4.25V maximum supply voltage allows the two rechargeable cells to be trickle- or fastcharged while driving the MAX3218. The circuit comprises three sections: power supply, transmitters, and receivers. The power-supply section converts the supplied input voltage to 6.5V, providing the voltages necessary for the drivers to meet true RS-232 levels. External components are small and inexpensive. The transmitters and receivers are guaranteed to operate at 120kbps data rates, providing compatibility with LapLink™ and other high-speed communications software. The MAX3218 is equipped with Maxim’s new proprietary AutoShutdown™ circuitry. This achieves a 1µA supply current by shutting down the device when the RS-232 cable is disconnected or when the connected peripheral transmitters are turned off. While shut down, both receivers can remain active or can be disabled under logic control. With this feature, the MAX3218 can be in low-power shutdown mode and still monitor activity on external devices. Three-state drivers are provided on both receiver outputs. Three-state drivers on both receiver outputs are provided so that multiple receivers, generally of different interface standards, can be wire-ORed at the UART. Switch-Mode Power Supply The switch-mode power supply uses a single inductor with one diode and three small capacitors to generate ±6.5V from an input voltage in the 1.8V to 4.25V range. Inductor Selection Use a 15µH inductor with a saturation current rating of at least 350mA and less than 1Ω resistance. Table 1 lists suppliers of inductors that meet the 15µH/350mA/1Ω specifications. ™ LapLink is a trademark of Traveling Software, Inc. AutoShutdown is a trademark of Maxim Integrated Products. _______________________________________________________________________________________ 5 MAX3218 ______________________________________________________________Pin Description MAX3218 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ Table 1. Suggested Component Suppliers MANUFACTURER PART NUMBER PHONE FAX Inductors Murata-Erie LQH4N150K-TA USA (814) 237-1431 USA (814) 238-0490 Sumida CD43150 USA (708) 956-0666 Japan (03) 3607-5111 USA (708) 956-0702 Japan (03) 3607-5428 TDK NLC453232T-150K USA (708) 803-6100 Japan (03) 3278-5111 USA (708) 803-6296 Japan (03) 3278-5358 Allegro TMPD6050LT USA (508) 853-5000 USA (508) 853-7556 Central Semiconductor CMPSH-3 (Schottky) USA (516) 435-1110 USA (516) 435-1824 Motorola MMBD6050LT1 (silicon) USA (408) 749-0510 USA (408) 991-7420 Philips PMBD6050 (silicon) USA (401) 762-3800 USA (401) 767-4493 1N6050 (silicon), 1N5817 (Schottky) USA (408) 749-0510 USA (408) 991-7420 Diodes—Surface-Mount Diodes—Through-Hole Motorola Diode Selection Key diode specifications are fast recovery time (<10ns), average current rating (>100mA), and peak current rating (>350mA). Inexpensive fast silicon diodes, such as the 1N6050, are generally recommended. More expensive Schottky diodes improve efficiency and give slightly better performance at very low VCC voltages. Table 1 lists suppliers of both surface-mount and through-hole diodes. 1N914s are usually satisfactory, but specifications and performance vary widely with different manufacturers. Capacitor Selection Use capacitors with values at least as indicated in Figure 1. Capacitor C2 determines the ripple on V+, but not the absolute voltage. Capacitors C1 and C3 determine both the ripple and the absolute voltage of V-. Bypass VCC to GND with at least 1µF (C4) placed close to pins 5 and 6. If the VCC line is not bypassed elsewhere (e.g., at the power supply), increase C4 to 4.7µF. You may use ceramic or polarized capacitors in all locations. If you use polarized capacitors, tantalum types are preferred because of the high operating frequency of the power supplies (about 250kHz). If aluminum electrolytics are used, higher capacitance values may be required. 1.8V to 4.25V 15µH C4 1µF 6 VCC 1N6050 1 LX C2 1µF 19 V+ V- 3 4 2 C3 1µF FORCEON FORCEOFF MAX3218 C1+ C1- INVALID 7 T1IN 8 T2IN 9 R1OUT 18 16 T1OUT 14 T1 T2OUT 13 T2 R1IN 12 R1 5k 10 R2OUT R2IN 11 R2 5k GND 5, 17, 20 Figure 1. Typical Operating Circuit 6 15 _______________________________________________________________________________________ C1 0.47µF 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ POWER MANAGEMENT UNIT OR KEYBOARD CONTROLLER MAX3218 FORCEON FORCEOFF X H H X L L RECEIVER STATUS Receiver Enabled Receiver Disabled Shutdown CPU I/O CHIP WITH UART RS-232 When FORCEOFF is low, power supplies are disabled and the transmitters are placed in a high-impedance state. Receiver operation is not affected by taking FORCEOFF low. Power consumption is dramatically reduced in shutdown mode. Supply current is minimized when the receiver inputs are static in any one of three states: floating (ground), GND, or VCC. AutoShutdown™ Figure 2. Interface Under Control of PMU RS-232 Drivers The two drivers are identical, and deliver EIA/TIA-232E and EIA/TIA-562 output voltage levels when V CC is between 1.8V and 4.25V. One transmitter can drive up to 3kΩ in parallel with 2500pF at up to 120kbps. Connect unused drivers to either GND or V CC. When FORCEOFF is driven low, or when AutoShutdown circuitry senses invalid voltage levels at all receiver inputs, the drivers are disabled and their outputs are forced into a high-impedance state. Driver inputs do not have internal pull-up resistors. RS-232 Receivers The two receivers are identical, and accept both EIA/TIA-232E and EIA/TIA-562 input signals. The CMOS receiver outputs are inverting and swing rail-torail. Receivers are disabled only when FORCEON and FORCEOFF inputs are low. (See Table 2.) A 1µA supply current is achieved with Maxim’s new AutoShutdown feature, which operates when FORCEON is low and FORCEOFF is high. When the MAX3218 senses no valid signal level on either receiver input for typically 30µs, the on-board power supply and drivers shut down, reducing supply current to 1µA. Internal 5kΩ resistors pull undriven receiver inputs to ground. This occurs if the RS-232 cable is disconnected or if the connected peripheral transmitters are turned off. The system turns on again when a valid level is applied to either RS-232 receiver input. As a result, the system saves power without changes to the existing BIOS or operating system. When using the AutoShutdown feature, INVALID is high when the device is on and low when the device is shut down. The INVALID output indicates the condition of the receiver inputs. Table 3 summarizes the MAX3218 operating modes. FORCEON and FORCEOFF override the automatic circuitry and force the transceiver into its normal operating state or into its low-power standby state. When neither control is asserted, the IC selects between these states automatically based on receiver input levels. Figure 4 depicts valid and invalid RS-232 receiver levels. The Table 3. AutoShutdown Logic RS-232 SIGNAL PRESENT AT RECEIVER INPUT FORCEOFF INPUT Yes No FORCEON INPUT INVALID OUTPUT TRANSCEIVER STATUS H X H Normal Operation H H L Normal Operation (Forced On) No H L L Shutdown (AutoShutdown) Yes L X H Shutdown (Forced Off) No L X L Shutdown (Forced Off) _______________________________________________________________________________________ 7 MAX3218 Table 2. Receiver Status FORCEOFF FORCEON INVALID MAX3218 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ MAX3218 shuts down after sensing invalid RS-232 levels for greater than 30µs, ensuring that the AutoShutdown mode is not enabled for slow-moving signals (>1V/µs). Another system with AutoShutdown may need a period of time to wake up. Figure 5 shows a circuit that forces the transmitters on for 100ms after start-up, allowing enough time for the other system to realize that the MAX3218 system is awake. If the other system outputs valid RS-232 signals within that time, the RS-232 ports on both systems remain enabled. __________Applications Information Operation from Regulated/Unregulated Dual System Power Supplies The MAX3218 is intended for use with three different power-supply sources: it can be powered directly from a battery, from a 3.0V or 3.3V power supply, or simultaneously from both. Figure 1 shows the single-supply configuration. Figure 6 shows the circuit for operation from both a 3V supply and a raw battery supply—an ideal configuration where a regulated 3V supply is being derived from two cells. In this application, the MAX3218’s logic levels remain appropriate for interface with 3V logic, yet most of the power for the MAX3218 is +0.3V to +2.8V drawn directly from the battery, without suffering the efficiency losses of the DC-DC converter. This prolongs battery life. Bypass the input supplies with 0.1µF at VCC (C4) and at least 1µF at the inductor (C5). Increase C5 to 4.7µF if the power supply has no other bypass capacitor connected to it. Low-Power Operation The following suggestions will help you get maximum life out of your batteries. Transmit at the highest practical data rate. Although this raises the supply current while transmission is in progress, the transmission will be over sooner. If the MAX3218 is shut down (using FORCEOFF) as soon as each transmission ends, this practice will save energy. Operate your whole system from the raw battery voltage rather than suffer the losses of a regulator or DCDC converter. If this is not possible, but your system is powered from two cells and employs a 3V DC-DC converter to generate the main logic supply, use the circuit of Figure 6. This circuit draws most of the MAX3218’s power straight from the battery, but still provides logiclevel compatibility with the 3V logic. + FORCEOFF POWER DOWN + -0.3V to -2.8V FORCEON R_IN Rx R_OUT • • • FORCEON FORCEOFF INVALID IS AN INTERNALLY GENERATED SIGNAL THAT IS USED BY THE AUTOSHUTDOWN LOGIC AND APPEARS AS AN OUTPUT OF THE DEVICE. POWER DOWN IS ONLY AN INTERNAL SIGNAL. IT CONTROLS THE OPERATIONAL STATUS OF THE TRANSMITTERS AND THE POWER SUPPLIES. • • • 30µs DELAY INVALID FORCEOFF 0 0 0 0 1 1 1 1 FORCEON 0 0 1 1 0 0 1 1 INVALID 0 1 0 1 0 1 0 1 Figure 3. AutoShutdown Logic 8 _______________________________________________________________________________________ POWER DOWN 0 0 0 0 0 1 1 1 Keep communications cables short to minimize capacitive loading. Lowering the capacitive loading on the transmitter outputs reduces the MAX3218’s power consumption. Using short, low-capacitance cable also helps transmission at the highest data rates. TRANSMITTERS ENABLED, INVALID HIGH EIA/TIA-232E and _____________EIA/TIA-562 Standards +2.8V INDETERMINATE +0.3V 0V AUTOSHUTDOWN, TRANSMITTERS DISABLED, 1µA SUPPLY CURRENT, INVALID LOW -0.3V INDETERMINATE -2.8V TRANSMITTERS ENABLED, INVALID HIGH (a) RECEIVER INPUT VOLTAGE (V) INVALID REGION VCC INVALID OUTPUT (V) 0 RS-232 circuits consume much of their power because the EIA/TIA-232E standard demands that the transmitters deliver at least 5V to receivers with impedances that can be as low as 3kΩ. For applications where power consumption is critical, the EIA/TIA-562 standard provides an alternative. EIA/TIA-562 transmitter output voltage levels need only reach ±3.7V, and because they have to drive the same 3kΩ receiver loads, the total power consumption is considerably reduced. Since the EIA/TIA-232E and EIA/TIA-562 receiver input voltage thresholds are the same, interoperability between EIA/TIA-232E and EIA/TIA-562 devices is guaranteed. Maxim’s MAX560 and MAX561 are EIA/TIA-562 transceivers that operate on a single supply from 3.0V to 3.6V, and the MAX562 transceiver operates from 2.7V to 5.25V while producing EIA/TIA-562 levels. POWER MANAGEMENT UNIT tINVL tINVH V+ VCC 0V MASTER SHDN LINE 0.1µF 1M FORCEOFF FORCEON MAX3218 VtWU (b) Figure 4. AutoShutdown Trip Levels Figure 5. AutoShutdown with Initial Turn-On to Wake Up a System _______________________________________________________________________________________ 9 MAX3218 AUTOSHUTDOWN RECEIVER INPUT THRESHOLD (V) 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ MAX3218 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ 15µH 3V DC-DC CONVERTER MAX878 OR MAX756 OR MAX856 1N6050 1µF C2 C5 1µF 6 C4 0.1µF 3 4 2 VCC 1 LX 19 V+ V- 15 C3 1µF FORCEON C1+ FORCEOFF INVALID 7 T1IN 8 T2IN 9 R1OUT 18 C1 0.47µF MAX3218 C1- 16 T1OUT 14 T1 T2OUT 13 T2 R1IN 12 R1 5k 10 R2OUT R2IN 11 R2 5k GND 5, 17, 20 Figure 6. Operating from Unregulated and Regulated Supplies 10 ______________________________________________________________________________________ 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ PART SUPPLY VOLTAGE (V) No. OF TRANSMITTERS/ RECEIVERS No. OF RECEIVERS ACTIVE IN SHUTDOWN GUARANTEED DATA RATE (kbps) EIA/TIA232 OR 562 MAX212 3.0 to 3.6 3/5 5 120 232 Drives mice MAX3212 2.7 to 3.6 3/5 5 120 232 AutoShutdown, complementary receiver, drives mice, transient detection MAX218 1.8 to 4.25 2/2 2 120 232 Operates directly from a battery without a voltage regulator MAX3218 1.8 to 4.25 2/2 2 120 232 Same as MAX218 but with AutoShutdown MAX560 3.0 to 3.6 4/5 2 120 562 Pin-compatible with MAX213 MAX561 3.0 to 3.6 4/5 0 120 562 Pin-compatible with MAX214 MAX562 2.7 to 5.25 3/5 5 230 562 Wide supply range MAX563 3.0 to 3.6 2/2 2 120 562 0.1µF capacitors MAX3222 3.0 to 5.5 2/2 2 120 232 0.1µF capacitors MAX3223 3.0 to 5.5 2/2 2 120 232 AutoShutdown, 0.1µF capacitors MAX3232 3.0 to 5.5 2/2 2 120 232 Pin-compatible with MAX232 MAX3241 3.0 to 5.5 3/5 5 120 232 0.1µF capacitors, 2 complementary receivers, drives mice MAX3243 3.0 to 5.5 3/5 1 120 232 0.1µF capacitors, AutoShutdown, complementary receiver, drives mice FEATURES ______________________________________________________________________________________ 11 MAX3218 _____+3V-Powered EIA/TIA-232 and EIA/TIA-562 Transceivers from Maxim MAX3218 1µA Supply Current, 1.8V to 4.25V-Powered RS-232 Transceiver with AutoShutdown™ ___________________Chip Topography INVALID LX GND V+ FORCEON C1+ FORCEOFF GND C1V- 0.101" (2.565mm) GND V CC T1OUT T1IN T2OUT T2IN R1IN R2OUT R2IN R1OUT 0.122" (3.099mm) TRANSISTOR COUNT: 571 SUBSTRATE CONNECTED TO GND ________________________________________________________Package Information DIM α E H C L A A1 B C D E e H L α INCHES MILLIMETERS MIN MAX MIN MAX 0.068 0.078 1.73 1.99 0.002 0.008 0.05 0.21 0.010 0.015 0.25 0.38 0.004 0.008 0.09 0.20 SEE VARIATIONS 0.205 0.209 5.20 5.38 0.0256 BSC 0.65 BSC 0.301 0.311 7.65 7.90 0.025 0.037 0.63 0.95 0˚ 8˚ 0˚ 8˚ DIM PINS e SSOP SHRINK SMALL OUTLINE PACKAGE A B A1 D D D D D 14 16 20 24 28 INCHES MILLIMETERS MAX MIN MAX MIN 6.33 0.239 0.249 6.07 6.33 0.239 0.249 6.07 7.33 0.278 0.289 7.07 8.33 0.317 0.328 8.07 0.397 0.407 10.07 10.33 21-0056A D 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. 12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 © 1995 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.