19-5929; Rev 0; 6/11 EVALUATION KIT AVAILABLE MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer General Description The MAX14778 dual 4:1 analog multiplexer supports analog signals up to Q25V with a single 3.0 to 5.5V supply. Each multiplexer has separate control inputs to allow independent switching, making the device ideal for multiplexing different communications signals with the same connector pins. Extended ESD protection of Q6kV (Human Body Model) enable direct interfacing to cables and connectors. The MAX14778 features a low 1.5I (max) on-resistance and 3mI (typ) flatness to maximize signal integrity over the entire common-mode voltage range. Each multiplexer can carry up to 300mA of continuous current through the multiplexer in either direction. The MAX14778 supports switching of full-speed USB 1.1 signals (12Mbps) and RS-485 data rates of up to 20Mbps. The MAX14778 is available in a 20-pin (5mm x 5mm) TQFN package and is specified over the -40NC to +85NC extended temperature range. Features S ±25V Signal Range S Single 3.0V to 5.5V Supply S Two Independent Multiplexers S 1.5I RON (max) S 3mI RON Flatness (typ) S 300mA Maximum Current Through Multiplexer S 78pF Input Capacitance S 75MHz Large-Signal Bandwidth S Break-Before-Make Operation S Extended ESD Protection on A_ and B_ Pins Q6kV Human Body Model (HBM) Ordering Information appears at end of data sheet. For related parts and recommended products to use with this part, refer to www.maxim-ic.com/MAX14778.related. Functional Diagram Applications RS-485/RS-232/USB 1.1 Multiplexing POS Peripherals ENA SA0 SA1 VDD Handheld Industrial Devices Communication Systems CONTROL A BIAS GENERATION VP VN Audio/Data Multiplexing Connector Sharing A0 Gaming Machines A1 MAX14778 ACOM A2 A3 B0 B1 BCOM B2 B3 CONTROL B ENB SB0 SB1 GND ����������������������������������������������������������������� Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) VDD. .........................................................................-0.3V to +6V VP............................ -0.3V to the lesser of +52V and (VN + 70V) VN................. The lesser of (VDD - 40V) and (VP - 70V) to +0.3V VP to VN. ................................................................-0.3V to +70V ENA, ENB, SA_, SB_................................. -0.3V to (VDD + 0.3V) A_, ACOM, B_, BCOM... (VN - 0.3V) to the lesser of (VP + 0.3V) and (VN + 52V) Continuous Current Through Switch.............................. ±500mA Continuous Power Dissipation (TA = +70NC) TQFN (derate 33.3mW/NC above +70NC)...............2666.7mW Operating Temperature Range........................... -40NC to +85NC Junction Temperature......................................................+150NC Storage Temperature Range............................. -65NC to +150NC Lead Temperature (soldering, 10s) ................................+300NC Soldering Temperature (reflow).......................................+260NC 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. PACKAGE THERMAL CHARACTERISTICS (Note 1) TQFN Junction-to-Ambient Thermal Resistance (BJA)...........30NC/W Junction-to-Case Thermal Resistance (BJC)..................2NC/W Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. ELECTRICAL CHARACTERISTICS (VDD = 3.0V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 5V, TA = +25NC.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 5.5 V DC CHARACTERISTICS Supply Voltage Range VDD 3.0 ENA = ENB = high Supply Current IDD VENA = VENB = VDD/2 Charge-Pump Threshold Analog Signal Range VDDTH VIN Continuous Current Through Switch ICOM On-Resistance RON On-Resistance Flatness RFLAT(ON) VDD P VDDTH 4.27 10 VDD > VDDTH 2.54 6 VDD P VDDTH 4.31 10 VDD > VDDTH 2.59 6 (Note 3) Figure 1, switch open or closed 4.64 mA V -25 +25 V -300 +300 mA 1.5 Ω 0.84 Figure 1, ICOM = Q300mA, VIN = Q25V Figure 1, -25V P VIN P +25V, ICOM = Q300mA 3 mΩ A_, B_ Off-Leakage Current IA(OFF), IB(OFF) Figure 2, VIN = 25V, VOUT = 0V -200 +200 nA ACOM, BCOM Off-Leakage Current IACOM(OFF), IBCOM(OFF) Figure 2, VOUT = 15V, VIN = 0V -1 +1 FA A_, B_ On-Leakage Current IA(ON), IB(ON) Figure 2, VIN = Q25V, ACOM or BCOM is unconnected -1 +1 FA ����������������������������������������������������������������� Maxim Integrated Products 2 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer ELECTRICAL CHARACTERISTICS (continued) (VDD = 3.0V to 5.5V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VDD = 5V, TA = +25NC.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS LOGIC INPUTS (ENA, ENB, SA_, SB_) Input Logic-Low Voltage VIL VDD = 5.5V 0.8 VDD = 4.5V 0.8 VDD = 3.6V 0.7 VDD = 3.0V Input Logic-High Voltage VIH V 0.7 VDD = 5.5V 2.1 VDD = 4.5V 2.0 VDD = 3.6V 1.9 VDD = 3.0V 1.7 V AC CHARACTERISTICS Power-Up Time tPOR 404 ms Enable Turn-On Time tON Figure 3, VIN = Q10V, RL = 10kI, CL = 15pF Enable Turn-Off Time tOFF Figure 3, VIN = Q10V, RL = 10kI, CL = 15pF Break-Before-Make Interval tBBM Figure 4, VIN = Q10V, RL = 10kI, CL = 15pF 840 Fs Figure 5, VA_ = 0V, CL = 1nF Charge Injection Q Off-Isolation VISO Figure 6, VA_ = 1VRMS, f = 100kHz, RL = 50I, CL = 15pF Crosstalk VCT Figure 6, f = 100kHz, RS = RL = 50I -3dB Bandwidth BW Figure 6, RS = 50I, RL = 50I Total Harmonic Distortion Plus Noise Input Capacitance THD+N CIN RS = RL = 1kI, f = 20Hz to 20kHz A_, B_ pins 2 ms 1.5 ms 1720 pC -80 dB -103 dB 75 MHz 0.003 % 78 pF THERMAL PROTECTION Thermal-Shutdown Threshold TSHUT 145 NC Thermal-Shutdown Hysteresis THYST 25 NC ESD PROTECTION A_, B_ Pins (Note 4) Human Body Model Q6 kV All Other Pins Human Body Model Q2 kV Note 2: All units are production tested at TA = +25NC. Specifications over temperature are guaranteed by design. Note 3: When VDD is higher than the charge-pump threshold, the internal 5V regulated charge pump is turned off and the input to the high-voltage charge pumps is provided by VDD. Note 4: The MAX14778 requires a 1µF capacitor on both VP and VN to GND to guarantee full ESD protection. See the Applications Information section for details on ESD test conditions. ����������������������������������������������������������������� Maxim Integrated Products 3 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Test Circuits/Timing Diagrams V +5V 1µF VDD MAX14778 A_ B_ VIN ACOM BCOM ICOM GND Figure 1. On-Resistance Measurement +5V +5V 1µF 1µF VDD IA(OFF) IB(OFF) A VIN VDD MAX14778 A_ B_ ACOM BCOM GND IACOM(OFF) IBCOM(OFF) IA(ON) IB(ON) A A VOUT VIN MAX14778 A_ B_ ACOM BCOM GND Figure 2. Leakage Current Measurement ����������������������������������������������������������������� Maxim Integrated Products 4 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Test Circuits/Timing Diagrams (continued) LOGIC INPUT MAX14778 VIN A_ B_ ACOM BCOM t R < 20ns t F < 20ns VIH VIL 50% VOUT RL t OFF CL ENA VOUT ENB SWITCH OUTPUT LOGIC INPUT 0.9 x V0UT 0.1 x VOUT 0V t ON CL INCLUDES FIXTURE AND STRAY CAPACITANCE. RL VOUT = VIN R + R L ON ( ) Figure 3. Turn-On/Turn-Off Timing +5V 1µF +5V VDD SA0 ENA SA1 tR < 20ns MAX14778 0V LOGIC INPUT LOGIC INPUT VOUT A_ ACOM VIN GND VOUT RL 80% SWITCH OUTPUT CL 0V tBBM CL INCLUDES FIXTURE AND STRAY CAPACITANCE. RL VOUT = VIN R + R L ON ( ) Figure 4. Break-Before-Make Timing ����������������������������������������������������������������� Maxim Integrated Products 5 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Test Circuits/Timing Diagrams (continued) +5V +5V A_ B_ VDD LOGIC INPUT OFF LOGIC INPUT OFF 0V MAX14778 ACOM BCOM ENA ENB ON VOUT C L = 1nF GND DVOUT VOUT Q = CL x DVOUT Figure 5. Charge Injection VDD OFF-ISOLATION = 20log NETWORK ANALYZER 0V OR VDD ENA SA_ 50I A0 50I VIN V ON-LOSS = 20log OUT VIN 50I MAX14778 ACOM VOUT MEAS 50I VOUT VIN REF V CROSSTALK = 20log OUT VIN 50I MEASUREMENTS ARE STANDARDIZED AGAINST SHORTS AT IC TERMINALS. OFF-ISOLATION IS MEASURED BETWEEN ACOM AND "OFF" A_ TERMINAL ON EACH MULTIPLEXER. -3dBW IS MEASURED BETWEEN ACOM AND "ON" A_ TERMINAL ON EACH MULTIPLEXER. CROSSTALK IS MEASURED FROM ONE CHANNEL TO ALL OTHER CHANNELS. SIGNAL DIRECTION THROUGH MULTIPLEXER IS REVERSED; WORST VALUES ARE RECORDED. Figure 6. Off-Isolation, -3dB Bandwidth, and Crosstalk ����������������������������������������������������������������� Maxim Integrated Products 6 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Typical Operating Characteristics (VDD = 5.0V, TA = +25°C, unless otherwise noted.) 0.97 VDD = 5V 0.96 1.1 TA = +85°C 1.0 0.9 TA = +25°C 0.8 0.7 0.6 IACOM = 300mA 0.95 -5 5 15 0.5 25 -15 -5 CHARGE INJECTION vs. ANALOG SIGNAL VOLTAGE MAX14778 toc04 -40 1,000 35 60 600 3.0 VDD = 3.3V 2.5 2.0 VDD = 5V 0.5 CL = 1nF 0 -25 85 -15 -5 5 15 0 -40 25 -15 10 OFF-ISOLATION vs. FREQUENCY -80 -100 A0 TO ACOM A2 SELECTED -2 -30 -40 -50 FREQUENCY (MHz) 100 -3 -4 -5 -6 -7 -8 A0 TO ACOM A0 SELECTED -9 -70 10 0 -1 -20 -60 -120 85 FREQUENCY RESPONSE VOUT / VIN (dB) OFF-ISOLATION (dB) -60 60 1 MAX14778 toc08 MAX14778 toc07 0 -10 35 TA (°C) VACOM (V) -40 1 85 1.0 200 CROSSTALK vs. FREQUENCY 0.1 60 3.5 1.5 TA (°C) A0 TO B0 A0 AND B0 SELECTED 35 4.0 IDD (mA) Q (pC) 10 10 SUPPLY CURRENT vs. TEMPERATURE 1,200 VA0 = 25V A0 SELECTED ACOM UNCONNECTED -15 -15 TA (°C) 400 -40 CROSSTALK (dB) 25 800 1 -20 15 ON-LEAKAGE CURRENT vs. TEMPERATURE 10 0 5 VACOM (V) 100 VA1 = 25V A0 SELECTED ACOM = GND 0.1 -25 VACOM (V) 1000 1 MAX14778 toc09 -15 10 TA = -40°C IACOM = 300mA MAX14778 toc05 -25 ON-LEAKAGE CURRENT (nA) 1.2 MAX14778 toc06 0.98 MAX14778 toc03 1.3 100 OFF-LEAKAGE CURRENT (nA) 1.4 ON-RESISTANCE (I) VDD = 3.3V MAX14778 toc02 0.99 ON-RESISTANCE (I) 1.5 MAX14778 toc01 1.00 OFF-LEAKAGE CURRENT vs. TEMPERATURE ON-RESISTANCE vs. COMMON-MODE VOLTAGE ON-RESISTANCE vs. COMMON-MODE VOLTAGE -10 0.1 1 10 FREQUENCY (MHz) 100 0.1 1 10 100 FREQUENCY (MHz) ����������������������������������������������������������������� Maxim Integrated Products 7 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Typical Operating Characteristics (continued) (VDD = 5.0V, TA = +25°C, unless otherwise noted.) MAX14778 toc10 A0 TO ACOM RS = 600I RL = 1kI VDD TO ACOM -20 -40 PSRR (dB) THD+N (%) 0.1 PSRR vs. FREQUENCY 0 MAX14778 toc11 THD+N vs. FREQUENCY 1 0.01 -60 -80 -100 0.001 -120 0.0001 -140 0.2 0.02 2 20 0.1 1 10 100 FREQUENCY (kHz) TURN-ON TIME vs. ANALOG-SIGNAL VOLTAGE TURN-OFF TIME vs. ANALOG-SIGNAL VOLTAGE 1.18 1.16 0.45 0.40 0.35 1.12 0.30 tOFF (ms) 1.14 1.10 1.08 0.25 0.20 1.06 0.15 1.04 0.10 1.02 0.05 1.00 MAX14778 toc13 0.50 MAX14778 toc12 1.20 tON (ms) 0.01 FREQUENCY (kHz) 0 -25 -15 -5 5 VACOM (V) 15 25 -25 -15 -5 5 15 25 VACOM (V) ����������������������������������������������������������������� Maxim Integrated Products 8 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer SB1 VDD SA1 SA0 TOP VIEW SB0 Pin Configuration 15 14 13 12 11 ENB 16 10 ENA B3 17 9 A3 8 A2 7 A1 6 A0 B2 18 MAX14778 B1 19 *EP *CONNECT EXPOSED PAD TO VN. 2 3 4 5 VN ACOM BCOM 1 GND + VP B0 20 TQFN 5mm x 5mm Pin Description PIN NAME 1 BCOM FUNCTION MUX B Common Terminal 2 VP 3 GND 4 VN 5 ACOM 6 A0 MUX A Bidirectional Analog Input/Output 0 7 A1 MUX A Bidirectional Analog Input/Output 1 8 A2 MUX A Bidirectional Analog Input/Output 2 9 A3 MUX A Bidirectional Analog Input/Output 3 10 ENA MUX A Enable Input 11 SA0 MUX A Channel Select Input 0 12 SA1 MUX A Channel Select Input 1 13 VDD Power-Supply Input. Bypass VDD to GND with a 1FF ceramic capacitor. 14 SB1 MUX B Channel Select Input 1 15 SB0 MUX B Channel Select Input 0 16 ENB MUX B Enable Input 17 B3 MUX B Bidirectional Analog Input/Output 3 18 B2 MUX B Bidirectional Analog Input/Output 2 19 B1 MUX B Bidirectional Analog Input/Output 1 20 B0 MUX B Bidirectional Analog Input/Output 0 — EP Exposed Pad. Connect EP to VN. EP is not intended as an electrical connection point. Positive Charge-Pump Output. Bypass VP to GND with a 1FF ceramic capacitor (35V or higher). Ground Negative Charge-Pump Output. Bypass VN to GND with a 1FF ceramic capacitor (30V or higher). MUX A Common Terminal ����������������������������������������������������������������� Maxim Integrated Products 9 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Truth Tables Table 1. MUX A Channel Selection Table 2. MUX B Channel Selection ENA SA1 SA0 ACOM CONNECTED TO ENB SB1 SB0 BCOM CONNECTED TO 0 X X Open 0 X X Open 1 0 0 A0 1 0 0 B0 1 0 1 A1 1 0 1 B1 1 1 0 A2 1 1 0 B2 1 1 1 A3 1 1 1 B3 X = Don’t care X = Don’t care Detailed Description The MAX14778 dual 4:1 analog multiplexer integrates bias circuitry to provide a Q25V analog voltage range with a single 3.0 to 5.5V supply. This extended input range allows multiplexing different communications signals such as RS-232, RS-485, audio and USB 1.1 onto the same connector. Integrated Bias Generation The MAX14778 contains a total of three charge pumps to generate bias voltages for the internal switches: a 5V regulated charge pump, a positive high-voltage (+35V) charge pump, and a negative high-voltage (-27V) charge pump. When VDD is above 4.7V (typ), the 5V regulated charge pump is bypassed and VDD provides the input for the highvoltage charge pumps, reducing overall supply current. An external 1.0FF capacitor is required for each high-voltage charge pump between VP/VN and GND. Analog Signal Levels The MAX14778 transmits signals of up to Q25V with a single 3.0 to 5.5V supply due to integrated bias circuitry. The device features 1.5Ω (max) on-resistance and 3mI (typ) flatness for analog signals between -25V and +25V (see the Typical Operating Characteristics). The current flow through the multiplexers can be bidirectional, allowing operation either as a multiplexer or demultiplexer. Digital Interface The MAX14778 has two digital select inputs for each MUX: SA1 and SA0 control MUX A; SB1 and SB0 control MUX B. Drive the digital select inputs high or low to select which input (A_, B_) is connected to the common terminal (ACOM, BCOM) for each MUX. See the Truth Tables for more information. Each MUX features an independent enable input (ENA and ENB). Drive ENA or ENB low to disconnect all inputs from the common terminal for that MUX, regardless of the status of the select inputs or the other enable input. Applications Information Connector Sharing The MAX14778 supports a Q25V analog signal range independently for each input/output, allowing physical connector sharing between interface types that have differing signal ranges. The multiprotocol connector-sharing application in the Typical Operating Circuits shows an application with RS-232, half-duplex RS-485, full-speed USB 1.1, and audio signals sharing the same connector. The device allows signals to pass over the entire signal range specified by each standard while safely isolating the unused transceivers. Power-Up Conditions Ensure that no negative signals are present on the A_, B_, or ACOM/BCOM inputs before one second has passed after applying VDD. ���������������������������������������������������������������� Maxim Integrated Products 10 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer High-ESD Protection Electrostatic discharge (ESD)-protection structures are incorporated on all pins to protect against electrostatic discharges up to Q2kV Human Body Model (HBM) encountered during handling and assembly. A_ and B_ are further protected against ESD up to Q6kV (HBM) without damage. The ESD structures withstand high ESD both in normal operation and when the device is powered down. After an ESD event, the MAX14778 continues to function without latchup. RC 1MI CHARGE CURRENTLIMIT RESISTOR RD 1.5kI 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. The MAX14778 requires a 1FF capacitor on both VP and VN to GND to guarantee full ESD protection. Human Body Model Figure 7 shows the Human Body Model. Figure 8 shows the current waveform it generates when discharged into a low impedance. This model consists of a 100pF capacitor charged to the ESD voltage of interest that is then discharged into the device through a 1.5kI resistor. IP 100% 90% DISCHARGE RESISTANCE Ir PEAK-TO-PEAK RINGING (NOT DRAWN TO SCALE) AMPERES HIGHVOLTAGE DC SOURCE CS 100pF STORAGE CAPACITOR DEVICE UNDER TEST 36.8% 10% 0 0 tRL TIME tDL CURRENT WAVEFORM Figure 7. Human Body ESD Test Model Figure 8. Human Body Current Waveform ���������������������������������������������������������������� Maxim Integrated Products 11 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Typical Operating Circuits +5V 1µF VDD VP RS-232 TRANSCEIVER TX A0 RX B0 A A1 B B1 D+ A2 D- B2 L A3 R B3 MAX14778 VN 1µF 1µF SHARED CONNECTOR +5V ACOM RS-485 TRANSCEIVER USB 1.1 TRANSCEIVER AUDIO SOURCE BCOM CONTROL ENA MULTIPROTOCOL CONNECTOR SHARING APPLICATION SA1 SA0 SB1 SB0 ENB GND CONTROL INPUTS ���������������������������������������������������������������� Maxim Integrated Products 12 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Typical Operating Circuits (continued) +5V 1µF VDD VP RS-232 TRANSCEIVER TX A0 RX B0 A A1 B B1 D+ A2 D- B2 CLOCK A3 DATA B3 MAX14778 VN 1µF 1µF SHARED CONNECTOR +5V ACOM RS-485 TRANSCEIVER USB 1.1 TRANSCEIVER KEYBOARD WEDGE BCOM CONTROL ENA SCANNER CONNECTOR SHARING APPLICATION SA1 SA0 SB1 SB0 ENB GND CONTROL INPUTS ���������������������������������������������������������������� Maxim Integrated Products 13 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Ordering Information PART TEMP RANGE PIN-PACKAGE MAX14778ETP+ -40NC to +85NC 20 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. Chip Information PROCESS: BiCMOS Package Information For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 20 TQFN-EP T2055+4 21-0140 90-0009 ���������������������������������������������������������������� Maxim Integrated Products 14 MAX14778 Dual ±25V Above- and Below-the-Rails 4:1 Analog Multiplexer Revision History REVISION NUMBER REVISION DATE 0 6/11 DESCRIPTION Initial release PAGES CHANGED — 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. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2011 Maxim Integrated Products 15 Maxim is a registered trademark of Maxim Integrated Products, Inc.