19-1461; Rev 0; 4/99 Serially Controlled, Clickless Audio/Video Switches The MAX4562/MAX4563 serial-interface controlled switches are ideal for multimedia applications. Each device features 30Ω max on-resistance (RON), 5Ω RON match, and 5Ω RON flatness. Audio off-isolation and crosstalk at 20kHz is -85dB, and video off-isolation and crosstalk at 10MHz is -55dB. Both devices feature “clickless” mode operation for audio applications. The MAX4562/MAX4563 contain two normally open single-pole/double-throw (SPDT) switches and two normally open single-pole/single-throw (SPST) switches. The MAX4562 features a 2-wire I 2 C™-compatible serial interface. The MAX4563 features a 3-wire SPI™/QSPI™/ MICROWIRE™-compatible serial interface. Both parts are available in 16-pin QSOP packages and operate over the commercial and extended temperature ranges. Applications Features ♦ Selectable Soft-Switching Mode for “Clickless” Audio Operation ♦ 30Ω max On-Resistance ♦ Audio Performance -85dB Off-Isolation at 20kHz -85dB Crosstalk at 20kHz -0.007% THD ♦ Video Performance -55dB Off-Isolation at 10MHz -55dB Crosstalk at 10MHz ♦ T-Switch Configurable for Improved Off-Isolation ♦ Serial Interface 2-Wire I2C-Compatible (MAX4562) 3-Wire SPI/QSPI/MICROWIRE-Compatible (MAX4563) ♦ Single-Supply Operation from +2.7V to +5.5V Set-Top Boxes PC Multimedia Boards Audio Systems Ordering Information Video Conferencing Systems PART Pin Configuration TEMP. RANGE PIN-PACKAGE MAX4562CEE 0°C to +70°C 16 QSOP MAX4562EEE MAX4563CEE MAX4563EEE -40°C to +85°C 0°C to +70°C -40°C to +85°C 16 QSOP 16 QSOP 16 QSOP TOP VIEW V+ 1 NO1A 2 16 SCL (SCLK) Typical Operating Circuit MAX4562 15 SDA (DIN) MAX4563 COM1 3 14 A0 (CS) NO1B 4 13 A1 (DOUT) 12 NO4 GND 5 SIGNAL IN NO2A 6 11 COM4 COM2 7 10 NO3 NO2B 8 9 NO2A COM2 NO2B SIGNAL OUT COM3 COM3 QSOP NO3 ( ) ARE FOR MAX4563 I2C is a trademark of Philips Corp. SPI/QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. MAX4562/MAX4563 General Description MAX4562/MAX4563 Serially Controlled, Clickless Audio/Video Switches ABSOLUTE MAXIMUM RATINGS V+ to GND ................................................................-0.3V to +6V NO_ _, COM_, DOUT to GND (Note 1) ........-0.3V to (V+ + 0.3V) SCL, SDA, CS, SCLK, DIN, A0, A1 to GND..............-0.3V to +6V Continuous Current into Any Terminal..............................±20mA Peak Current (NO_ _, COM_ pulsed at 1ms, 10% duty cycle max) .....................................................±50mA Continuous Power Dissipation (TA = +70°C) 16-Pin QSOP (derate 8.3mW/°C above +70°C)............667mW Operating Temperature Ranges MAX456_CEE....................................................0°C to +70°C MAX456_EEE .................................................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10sec) .............................+300°C Note 1: Signals on NO_ _ or COM_ exceeding V+ or ground are clamped by internal diodes. Limit forward-diode current to maximum current rating. 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—Single +5V Supply (V+ = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V+ V ANALOG SWITCHES Analog Signal Range (Note 3) On-Resistance VNO_ _, VCOM_ RON On-Resistance Match Between Channels (Note 4) ∆RON On-Resistance Flatness (Note 5) RFLAT NO_ _ Off-Leakage Current (Note 6) INO_ _(OFF) COM_ Off-Leakage Current (Note 6) ICOM_(OFF) COM_ On-Leakage Current (Note 6) ICOM_(ON) 0 ICOM_ = 4mA, VNO_ _ = 3V, V+ = 4.75V TA = +25°C ICOM_ = 4mA, VNO_ _ = 3V, V+ = 4.75V TA = +25°C 20 TA = TMIN to TMAX 30 Ω 40 3 5 Ω 7 TA = TMIN to TMAX ICOM_ = 4mA; TA = +25°C VNO_ _ = 1V, 2V, 3V; TA = TMIN to TMAX V+ = 4.75V 2 5 Ω 7 VNO_ _ = 4.5V, 1V; VCOM_ = 1V, 4.5V; V+ = 5.25V TA = +25°C -1 TA = TMIN to TMAX -10 VCOM_ = 1V, 4.5V; VNO_ _ = 4.5V, 1V; V+ = 5.25V TA = +25°C -1 TA = TMIN to TMAX -10 VCOM_ = 4.5V, 1V; VNO_ _ = 4.5V, 1V, or floating; V+ = 5.25V TA = +25°C -1 TA = TMIN to TMAX -10 0.001 1 nA 10 0.001 1 nA 10 0.002 1 nA 10 AUDIO PERFORMANCE Total Harmonic Distortion plus Noise THD+N Off-Isolation (Note 7) VISO(A) fIN = 1kHz, VNO_ _ = RL = 600Ω 1VRMS, VNO_ _ = 2.5V RL =10kΩ VNO_ _ = 1VRMS, fIN = 20kHz, RL = 600Ω, Figure 1 Channel-to-Channel Crosstalk VCT(A) VNO_ _ = 1VRMS, fIN = 20kHz, RS = 600Ω, Figure 1 2 0.07 0.006 % -85 dB -85 dB _______________________________________________________________________________________ Serially Controlled, Clickless Audio/Video Switches (V+ = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS VIDEO PERFORMANCE Off-Isolation (Note 7) VISO(V) VNO_ _ = 1VRMS, fIN = 10MHz, RL = 50Ω, Figure 1 -55 dB Channel-to-Channel Crosstalk VCT(V) VNO_ _ = 1VRMS, fIN = 10MHz, RS = 50Ω, Figure 1 -55 dB RSOURCE = 50Ω, RL = 50Ω 300 MHz fIN = 1MHz 10 pF -3dB Bandwidth BW Off-Capacitance COFF(NO) DYNAMIC TIMING WITH CLICKLESS MODE DISABLED (Note 8, Figure 2) Turn-On Time tONSD Turn-Off Time tOFFSD Break-Before-Make Time tBBM VNO_ _ = 2.5V, RL = 5kΩ, CL = 35pF TA = +25°C VNO_ _ = 2.5V, RL = 300Ω, CL = 35pF TA = +25°C 200 400 ns TA = TMIN to TMAX 500 100 160 ns TA = TMIN to TMAX VNO_ _ = 2.5V, TA = TMIN to TMAX 200 10 50 ns DYNAMIC TIMING WITH CLICKLESS MODE ENABLED (Note 8, Figure 2) Turn-On Time tONSE VNO_ _ = 2.5V, RL = 5kΩ, CL = 35pF 12 ms Turn-Off Time tOFFSE VNO_ _ = 2.5V, RL = 300Ω, CL = 35pF 3 ms POWER SUPPLY Supply Voltage Range V+ TA = TMIN to TMAX Supply Current (Note 9) I+ All logic inputs = 0 or V+, TA = TMIN to TMAX 2.7 5.5 V 6 10 µA TYP MAX UNITS V+ V ELECTRICAL CHARACTERISTICS—Single +3V Supply (V+ = +3V ±10%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN ANALOG SWITCHES Analog Signal Range (Note 3) On-Resistance VNO_ _, VCOM_ RON On-Resistance Match Between Channels (Note 4) ∆RON 0 ICOM_ = 4mA, VNO_ _ = 1V, V+ = 2.7V TA = +25°C ICOM_ = 4mA, VNO_ _ = 1V, V+ = 2.7V TA = +25°C 30 TA = TMIN to TMAX TA = TMIN to TMAX 60 Ω 80 3 5 Ω 7 _______________________________________________________________________________________ 3 MAX4562/MAX4563 ELECTRICAL CHARACTERISTICS—Single +5V Supply (continued) MAX4562/MAX4563 Serially Controlled, Clickless Audio/Video Switches ELECTRICAL CHARACTERISTICS—Single +3V Supply (continued) (V+ = +3V ±10%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2) PARAMETER On-Resistance Flatness (Note 5) SYMBOL RFLAT NO_ _ Off-Leakage Current (Notes 6, 10) INO_ _(OFF) COM_ Off-Leakage Current (Notes 6, 10) ICOM_(OFF) COM _ On-Leakage Current (Notes 6, 10) ICOM_(ON) CONDITIONS MIN ICOM_ = 4mA; VNO_ _ = 1V, 1.5V, 2V; V+ = 2.7V TA = +25°C VCOM_ = 0.5V, 3V; VNO_ _ = 3V, 0.5V; V+ = 3.6V TA = +25°C -1 TA = TMIN to TMAX -10 VCOM_ = 0.5V, 3V; VNO_ _ = 3V, 0.5V; V+ = 3.6V TA = +25°C -1 TA = TMIN to TMAX -10 VCOM_ = 3V, 0.5V; VNO_ _ = 3V, 0.5V, or floating; V+ = 3.6V TA = +25°C -1 TA = TMIN to TMAX -10 TYP MAX 3 6 TA = TMIN to TMAX UNITS Ω 8 0.001 1 nA 10 0.001 1 nA 10 0.002 1 nA 10 AUDIO PERFORMANCE RL = 600Ω 0.1 RL = 10kΩ 0.01 Total Harmonic Distortion plus Noise THD+N fIN = 1kHz, VNO_ _ = 0.5VRMS, VNO_ _ = 1.5V Off-Isolation (Note 7) VISO(A) VNO_ _ = 0.5VRMS, fIN = 20kHz, RL = 600Ω, Figure 1 80 dB Channel-to-Channel Crosstalk VCT(A) VNO_ _ = 0.5VRMS, fIN = 20kHz, RS = 600Ω, Figure 1 85 dB Off-Isolation (Note 7) VISO(V) VNO_ _ = 0.5VRMS, fIN = 10MHz, RL = 50Ω, Figure 1 -50 dB Channel-to-Channel Crosstalk VCT(V) VNO_ _ = 0.5VRMS, fIN = 10MHz, RS = 50Ω, Figure 1 -55 dB RSOURCE = 50Ω, RL = 50Ω 200 MHz fIN = 1MHz 10 pF % VIDEO PERFORMANCE -3dB Bandwidth BW Off-Capacitance COFF(NO) DYNAMIC TIMING WITH CLICKLESS MODE DISABLED (Notes 8, 12, and Figure 2) Turn-On Time tONSD Turn-Off Time tOFFSD Break-Before-Make Time tBBM VNO_ _ = 1.5V, RL = 5kΩ, CL = 35pF TA = +25°C 400 TA = TMIN to TMAX TA = +25°C VNO_ _ = 1.5V, RL = 300Ω, CL = 35pF TA = TMIN to TMAX VNO_ _ = 1.5V, TA = TMIN to TMAX 800 1000 200 350 500 10 ns ns 100 ns DYNAMIC TIMING WITH CLICKLESS MODE ENABLED (Notes 8, 12, and Figure 2) Turn-On Time tONSE VNO_ _ = 1.5V, RL = 5kΩ, CL = 35pF 12 ms Turn-Off Time tOFFSE VNO_ _ = 1.5V, RL = 300Ω, CL = 35pF 3 ms 4 _______________________________________________________________________________________ Serially Controlled, Clickless Audio/Video Switches (V+ = +2.7V to +5.25V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP DIGITAL INPUTS (SCLK, DIN, CS, SCL, SDA, A0, A1) V+ = 5V Input Low Voltage VIL V+ = 3V Input High Voltage VIH Input Hysteresis VHYST Input Leakage Current ILEAK Input Capacitance MAX UNITS 0.8 V 0.6 V+ = 5V 3 V+ = 3V 2 Digital inputs = 0 or V+ -1 V 0.2 CIN f = 1MHz Output Low Voltage VOL ISINK = 6mA DOUT Output High Voltage VOH ISOURCE = 0.5mA 0.001 V 1 5 µA pF DIGITAL OUTPUTS (DOUT, SDA) 0.4 V V+ - 0.5 V 2-WIRE TIMING CHARACTERISTICS (Figure 3, V+ = +2.7V to +5.25V, fSCL = 100kHz, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL SCL Clock Frequency fSCL Bus Free Time between Stop and Start Conditions tBUF CONDITIONS V+ = 2.7V to 5.25V MIN 0 V+ = 4.75V to 5.25V MAX 100 400 UNITS kHz 4.7 µs Hold Time After Start Condition tHD:STA 4.0 µs Stop Condition Setup Time tSU:STO 4.0 µs Data Hold Time tHD:DAT 0 µs Data Setup Time tSU:DAT 250 ns Clock Low Period tLOW 4.7 µs Clock High Period tHIGH 4.0 µs SCL/SDA Rise Time tR 20 + 0.1Cb 300 ns SCL/SDA Fall Time tF 20 + 0.1Cb 300 ns 0 50 ns Pulse Width of Suppressed Spike The first clock is generated after this period TYP _______________________________________________________________________________________ 5 MAX4562/MAX4563 I/O INTERFACE CHARACTERISTICS 3-WIRE TIMING CHARACTERISTICS (Figure 5, V+ = +2.7V to +5.25V, fOP = 2.1MHz, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL Operating Frequency CONDITIONS MIN V+ = 2.7V to 5.25V V+ = 4.75V to 5.25V fOP TYP 0 MAX UNITS 2.1 10 MHz DIN to SCLK Setup tDS 100 ns DIN to SCLK Hold tDH 0 ns CS Fall to SCLK Rise Setup tCSS 100 ns CS Fall to SCLK Rise Hold tCSH 0 ns SCLK Pulse Width Low tCL 200 ns SCLK Pulse Width High tCH 200 ns Rise Time (SCLK, DIN, CS) tR 2 µs Fall Time (SCLK, DIN, CS) tF 2 µs 200 ns SCLK Fall to Output Data Valid tDO CS Pulse Width High CLOAD = 50pF tCSW 40 ns The algebraic convention is used in this data sheet; the most negative value is shown in the minimum column. Guaranteed by design. Not subject to production testing. ∆RON = RON(MAX) - RON(MIN). Resistance flatness is defined as the difference between the maximum and minimum on-resistance values, as measured over the specified analog signal range. Note 6: Leakage parameters are 100% tested at maximum rated temperature and guaranteed by correlation at TA = +25°C. Note 7: Off-isolation = 20 log (VCOM_ / VNO_ _ ), VCOM_ = output, VNO_ _ = input to off switch. Note 8: All timing is measured from the clock’s falling edge preceding the ACK signal for 2-wire and from the rising edge of CS for 3-wire. Turn-off time is defined at the output of the switch for a 0.5V change, tested with a 300Ω load to ground. Turn-on time is defined at the output of the switch for a 0.5V change and measured with a 5kΩ load resistor to GND. All timing is shown with respect to 20% V+ and 70% V+, unless otherwise noted. Note 9: Supply current can be as high as 2mA per switch during switch transitions in the clickless mode, corresponding to a 12mA total supply transient current requirement. Note 10: Leakage testing is guaranteed by testing with a +5.25V supply. Note 11: Cb = capacitance of one bus line in pF. Tested with Cb = 400pF. Note 12: Typical values are for MAX4563 devices. Note 2: Note 3: Note 4: Note 5: Typical Operating Characteristics (V+ = +5V, TA = +25°C, unless otherwise noted.) ON-RESISTANCE vs. COM_ VOLTAGE AND TEMPERATURE 25 23 V+ = 3.3V 21 19 100 TA = +70°C 18 17 TA = +25°C 16 2 3 VCOM_ (V) COM_ON NO_ _OFF 1 TA = -40°C 12 1 10 13 15 0 COM_OFF 15 14 V+ = 5.0V 17 6 TA = +85°C 19 ON-RESISTANCE (Ω) 27 20 CURRENT (pA) V+ = 2.7V 1000 MAX4562 TOC02 29 LEAKAGE CURRENT vs. TEMPERATURE 21 MAX4562 otc01 31 MAX4562/3toc03 ON-RESISTANCE vs. COM_ VOLTAGE ON-RESISTANCE (Ω) MAX4562/MAX4563 Serially Controlled, Clickless Audio/Video Switches 4 5 0.1 0 1 2 3 VCOM_ (V) 4 5 -40 -15 10 35 TEMPERATURE (°C) _______________________________________________________________________________________ 60 85 Serially Controlled, Clickless Audio/Video Switches 250 TIME (ns) Q (pC) 0 -1 100 5.2 -2 50 10 35 60 85 0 1 TEMPERATURE (°C) 2 3 4 tOFF, V+ = +5V -40 5 -15 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY 600Ω IN AND OUT SIGNAL = 1VRMS 35 60 85 VIDEO FREQUENCY RESPONSE AUDIO FREQUENCY RESPONSE 0 MAX4562 toc07 1 10 TEMPERATURE (°C) VCOM_ (V) 0 MAX4526 toc08 -15 tOFF, V+ = +3V 0 -3 -40 tON, V+ = +5V 150 5.3 5.1 tON, V+ = +3V 200 1 5.4 MAX4562/3toc06 2 5.5 300 MAX4562 toc05 5.6 SUPPLY CURRENT (µA) 3 MAX4562/3toc04 5.7 TURN-ON AND TURN-OFF TIMES vs. TEMPERATURE (HARD MODE) CHARGE INJECTION vs. COM_ VOLTAGE 600Ω IN AND OUT -20 MAX4562 toc09 SUPPLY CURRENT vs. TEMPERATURE INSERTION LOSS -20 0.1 LOSS (dB) LOSS (dB) -60 OFF-ISOLATION -40 OFF-ISOLATION -60 -80 CROSSTALK CROSSTALK -80 -100 50Ω IN AND OUT 0.01 -100 -120 100 1000 10,000 100,000 10 100 1k 10k 100k 0.1 TURN-ON AND TURN-OFF TIMES (SOFT MODE) CS (5V/div) tON (1V/div) 1 10 100 FREQUENCY (MHz) FREQUENCY (Hz) FREQUENCY (Hz) TURN-ON AND TURN-OFF TIMES (HARD MODE) MAX4562 toc13 10 MAX4562 toc10 THD+N (%) -40 CS (5V/div) tON (1V/div) tOFF (1V/div) tOFF (1V/div) 5ms/div 100ns/div _______________________________________________________________________________________ 7 MAX4562/MAX4563 Typical Operating Characteristics (continued) (V+ = +5V, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (V+ = +5V, TA = +25°C, unless otherwise noted.) SOFT-MODE RISE TIME AMPLITUDE (500mV/div) MAX4562 toc12 MAX4562 toc11 SOFT-MODE FALL TIME AMPLITUDE (500mV/div) MAX4562/MAX4563 Serially Controlled, Clickless Audio/Video Switches 500µs/div 500µs/div Pin Description PIN 8 NAME FUNCTION MAX4562 MAX4563 1 1 V+ 2, 4, 6, 8, 10, 12 2, 4, 6, 8, 10, 12 NO1A, NO1B, NO2A, NO2B, NO3, NO4 Normally Open Terminals 3, 7, 9, 11 3, 7, 9, 11 COM1–COM4 Common Terminals 5 5 GND 13 – A1 – 13 DOUT 14 – A0 LSB + 1 of 2-Wire Serial Interface Address Field Positive Supply Voltage Ground LSB + 2 of 2-Wire Serial Interface Address Field Data Input of 3-Wire Serial Interface – 14 CS Chip-Select of 3-Wire Serial Interface 15 – SDA Data Input of 2-Wire Serial Interface – 15 DIN Data Input of 3-Wire Serial Interface 16 – SCL Clock Input of 2-Wire Serial Interface – 16 SCLK Clock Input of 3-Wire Serial Interface _______________________________________________________________________________________ Serially Controlled, Clickless Audio/Video Switches V+ 2/3 RL RL 50Ω COM2 NO2A GND N.C. 2/3 DECODER/ CONTROLLER SIGNAL GENERATOR 0dBm NO_ _ NO1 B COM1 ANALYZER DECODER/ CONTROLLER SIGNAL GENERATOR 0dBm V+ 10nF COM_V+ ANALYZER MAX4562/MAX4563 MAX4562 MAX4563 V+ 10nF GND a) OFF-ISOLATION b) CROSSTALK Figure 1. Off-Isolation and Crosstalk ACKNOWLEDGE BIT 3V MAX4562 MAX4563 0 V+ VOUT 10nF 2-WIRE 0 V+ VNO_ _ 2 OR 3 µP tR < 20ns tF < 20ns 50% SCL NO_ _ -0.5V tON VOUT COM _ VOUT RL 300Ω 0 VOUT - 0.5V tOFF CL 35pF 3V DECODER/ CONTROLLER CS 50% 0 SERIAL INTERFACE VOUT 0.9 • VOUT GND 3-WIRE 0 tON CL INCLUDES FIXTURE AND STRAY CAPACITANCE. VOUT = VCOM [RL / (RL + RON)] VOUT 0 0.1 • VOUT tOFF Figure 2. Switching Time _______________________________________________________________________________________ 9 MAX4562/MAX4563 Serially Controlled, Clickless Audio/Video Switches Detailed Description The MAX4562/MAX4563 are serial-interface controlled switches with soft-mode “clickless” and hard-mode operating capability. The MAX4562/MAX4563 contain two SPST switches and two SPDT switches. The SPDT switches are actually 2-to-1 multiplexers, in that each SPDT is really two independent SPST switches with a common node, as shown in the Pin Configuration. Each switch is controlled independently by either the 2-wire I2C-compatible or 3-wire SPI/QSPI/MICROWIRE-compatible serial interface. Audio off-isolation and crosstalk is -85dB at 20kHz. Video off-isolation and crosstalk is at least -55dB at 10MHz. Each switch of either device may be set to operate in either soft or hard mode. In soft mode, the switching 70% SDA transition is slowed to avoid the audible “clicking” that can occur when switches are used to route audio signals. In hard mode, the switches are not slowed down, making this mode useful when a faster response is required. If a new command is issued while any softmode switch is transitioning, the switch transition time is decreased so it reaches its final state before the new command is executed. Soft mode and open are the power-up default states for all switches. Switches in the same mode are guaranteed to be break-before-make relative to each other. Break-before-make does not apply between switches operating in different modes. These devices operate from a +2.7V to +5.5V single supply. The MAX4562 features a 2-wire I2C-compatible serial interface, and the MAX4563 features a 3-wire SPI/QSPI/MICROWIRE-compatible serial interface. 70% 20% 20% 70% 20% tSU, DAT 70% 20% 70% 20% tBUF tSU, STA tHD, STA tLOW 70% 20% SCL tSU, STO tHD, DAT 70% 20% tHIGH tHD, STA tR 70% 20% 70% 70% 70% tF START CONDITION REPEATED START CONDITION STOP CONDITION Figure 3. 2-Wire Serial-Interface Timing Diagram COMMAND BYTE SLAVE ADDRESS BYTE SDA MSB LSB ACK MSB LSB ACK SCL START CONDITION STOP CONDITION Figure 4. A Complete 2-Wire Serial-Interface Transmission 10 ______________________________________________________________________________________ START CONDITION Serially Controlled, Clickless Audio/Video Switches C1 C0 COMMAND 0 0 NO_OP No Operation 0 1 NO_OP No Operation 1 0 SWITCHSET 1 1 MODESET Table 2. Control-Bit Mapping CONTROL BIT SWITCH SWITCH TERMINAL D5 SW1A 2, 3 D4 SW1B 3, 4 D3 SW2A 6, 7 D2 SW2B 7, 8 D1 SW3 9, 10 D0 (LSB) SW4 11, 12 Applications Information Switch Control The MAX4562/MAX4563 have a common commandand control-bit structure; the only difference is the interface type (2-wire or 3-wire). The SWITCHSET command controls the open/closed states of the various switches. MODESET controls soft/hard-mode switch states. The NO_OP command is useful for daisy-chaining multiple 3-wire parts. Table 1 shows the command bits’ configuration and their related commands. Table 2 shows the configuration of the data bits and their related switches. After a SWITCHSET command is issued, a logic “1” in any data-bit location closes the associated switch, while a logic “0” opens it. After a MODESET command, a logic “1” in any data-bit location sets the associated switch into soft mode, while a logic “0” sets it into hard mode. 2-Wire Serial Interface The MAX4562 uses a 2-wire I2C-compatible serial interface, requiring only two I/O lines of a standard microprocessor port for communication. These devices use a SendByte™ protocol. The SendByte protocol consists of one byte of address field followed by one byte of command field. The first byte of any 2-wire serial-interface transaction is always the address byte. To address a given chip, the DESCRIPTION Sets specified switches open or closed. Sets specified switches to soft or hard mode. A0 and A1 bits in the address byte (Table 3) must duplicate the values present at the A0 and A1 pins of that chip, and the rest of the address bits must be configured as shown in Table 3. Connect the A0 and A1 pins to V+ or GND or drive them with CMOS logic levels. The second byte is the command byte, which sets the command being written to the device. The possible commands are MODESET and SWITCHSET. Figures 3 and 4 and the I/O Interface Characteristics detail the timing of the 2-wire serial-interface protocol. All bytes of the transmission, whether address or command, are sent MSB first. The MAX4562/MAX4563 are receive-only devices and must be controlled by a bus master device. A bus master signals the beginning of a transmission with a start condition by transitioning SDA from high to low while SCL is high. The slave devices monitor the serial bus continuously, waiting for the start condition followed by an address byte. When a device recognizes its address byte, it acknowledges by pulling the SDA line low for one clock period; it is then ready to accept the command byte. The device also issues a similar acknowledgment after the command byte. When the master has finished communicating with the slave, it issues a stop condition by transitioning SDA from low to high while SCL is high. The bus is then free for another transmission. 3-Wire Serial Interface The MAX4563 uses a 3-wire SPI/QSPI/MICROWIRE-compatible serial interface. An active-low chip select (CS) pin enables the device to receive data from the serial input pin, DIN. Command and data information are clocked in on the rising edge of the serial clock signal (SCLK) MSB first. A total of eight bits is needed in each write cycle. The command code is contained in the two MSBs of the 8-bit word. The remaining bits control the switches as shown in Table 4. While shifting in the serial data, the device remains in its original configuration. A rising edge on CS latches the data into the MAX4563’s internal register, initiating the device’s change of state. Table 4 shows the details of the 3-wire interface structure. SendByte is a trademark of Philips Corp. ______________________________________________________________________________________ 11 MAX4562/MAX4563 Table 1. Command-Bit Mapping MAX4562/MAX4563 Serially Controlled, Clickless Audio/Video Switches Table 3. MAX4562 2-Wire Serial-Interface Data Format ADDRESS BYTE MSB SRT 1 0 COMMAND BYTE LSB 0 1 1 A1 A0 MSB 0 ACK C1 LSB C0 SW2A SW1B SW2A SW2B SW3 SW4 ACK STP STP = Stop Condition Logic “0” in any data bit location places the associated switch open or in hard switching mode. Logic “1” in any data bit location places the associated switch closed or in soft (clickless) switching mode. See Table 1 for command-bit configuration. Table 4. MAX4563 3-Wire Serial-Interface Data Format COMMAND SWITCH CONTROL MSB LSB D7 D6 C1 C0 D5 D4 D3 D2 SW1A SW1B SW2A SW3B D1 D0 SW3 SW4 Figures 5 and 6 and the I/O Interface Characteristics show the timing details of the 3-wire interface. If the two command bits initiate a SWITCHSET command, a logic “1” in a switch control location closes the associated switch, while a logic “0” opens it. If the command bits initiate a MODESET command, a logic “1” in a switch control location sets the associated switch into soft “clickless” mode, while a logic “0” sets it into hard mode. For command-bit configurations, see Table 1. Using Multiple Devices There are two ways to connect multiple devices to the same 3-wire serial interface. The first involves using the DOUT pin. DOUT presents a copy of the last bit of the internal shift register, useful for daisy-chaining multiple devices. Data at DOUT are simply the input data delayed by eight clock cycles, appearing synchronous with SCLK’s falling edge. After CS goes high, DOUT holds the last bit in the shift register until new data are shifted into DIN. For a simple interface using several MAX4563 devices, daisy-chain the shift registers by connecting DOUT of the first device to DIN of the second, etc. Connect the CS pins of all devices together. 12 Data are shifted through the MAX4563 in series. When CS is brought high, all devices are updated simultaneously. If any of the devices in the chain are to be left unchanged, use a NO_OP command for that device, as shown in Table 1. An alternate way of connecting multiple devices is to decode the CS line. In this case, do not use the DOUT pin and connect the DIN pins of all devices together. Address decode logic individually controls the CS line of each device. When a device is to be selected, its CS line is brought low, data are shifted in, and its CS line is then brought high to execute the command. For command bit configuration see Table 1. T-Switches Configure the MAX4562/MAX4563 as a T-switch to improve off-isolation. As the signal frequency is increased, parasitic capacitance significantly degrades the off-isolation. Figure 7 shows a typical T-switch configuration using the MAX4562/MAX4563 to improve offisolation. COM2 and COM3 are tied together to create a single common node. NO2A and NO2B act as the input and output of the T-switch, while NO3 is tied to ground. When both SW2A and SW2B are closed, SW3 should be open to allow the signal to pass into NO2A and out of NO2B. However, when SW2A and SW2B are open, energy that is coupled through the open switches is shunted to ground through SW3, which should now be closed. This increases the off-isolation to typically -68dB at 10MHz (Figure 8). ______________________________________________________________________________________ Serially Controlled, Clickless Audio/Video Switches 20% 70% tCSW tCSH SCLK 20% tDH 20% tCSO tCH tCL tCSS MAX4562/MAX4563 20% CS 20% 20% 70% 70% 70% 20% tDS D6 D7 DIN D1 D0 tDO DOUT Figure 5. 3-Wire Serial-Interface Timing Diagram SWITCHES UPDATED CS -20 SCLK -40 OFF-ISOLATION (dB) DATA CLOCKED IN DIN D7 D6 D5 D4 D3 D2 D1 D0 LSB MSB SPST SWITCH -60 -80 T-SWITCH -100 INPUT DATA BITS DATA CLOCKED OUT -120 DOUT 0.1 D7 D6 D5 D4 D3 D2 D1 D0 D7 1 10 100 FREQUENCY (MHz) DATA BITS FROM PREVIOUS DATA INPUT DOUT POWER-UP DEFAULT: D7–D0 = 0 Figure 8. Off-Isolation vs. Frequency Figure 6. A Complete 3-Wire Serial-Interface Transmission ___________________Chip Information SIGNAL IN NO2A COM2 NO2B TRANSISTOR COUNT: 3518 SIGNAL OUT COM3 NO3 Figure 7. T-Switch Configuration ______________________________________________________________________________________ 13 MAX4562/MAX4563 Serially Controlled, Clickless Audio/Video Switches QSOP.EPS Package Information 14 ______________________________________________________________________________________ Serially Controlled, Clickless Audio/Video Switches ______________________________________________________________________________________ MAX4562/MAX4563 NOTES 15 MAX4562/MAX4563 Serially Controlled, Clickless Audio/Video Switches NOTES Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.