DG406-DG407

General Description Maxim’s redesigned DG406 and DG407 CMOS analog multiplexers now feature guaranteed matching between channels (8Ω, max) and flatness over the specified sig- nal range (9Ω, max). These low on-resistance muxes (100Ω, max) conduct equally well in either direction and feature guaranteed low charge injection (15pC, max). In addition, these new muxes offer low input off-leakage current over temperature—less than 5nA at +85°C. The DG406 is a 1 of 16 multiplexer/demultiplexer and the DG407 is a dual 8-channel multiplexer/demultiplex- er. Both muxes operate with a +5V to +30V single sup- ply and with ±4.5V to ±20V dual supplies. ESD protection is guaranteed to be greater than 2000V per Method 3015.7 of MIL-STD 883. These improved muxes are pin-compatible plug-in upgrades for the industry standard DG406 and DG407. ________________________Applications Sample-and-Hold Circuits Test Equipment Guidance and Control Systems Communications Systems Data-Acquisition Systems Audio Signal Routing ____________________________Features ♦♦ Pin-Compatible Plug-In Upgrade for Industry Standard DG406/DG407 ♦♦ Guaranteed Matching Between Channels, 8Ω (max) ♦♦ Guaranteed On-Resistance Flatness, 9Ω (max) ♦♦ Guaranteed Low Charge Injection, 15pC (max) ♦♦ Low On-Resistance 100Ω (max) ♦♦ Input Leakage, 5nA (max) at +85°C ♦♦ Low Power Consumption, 1.25mW (max) ♦♦ Rail-to-Rail Signal Handling ♦♦ Digital Input Controls TTL/CMOS Compatible ♦♦ ESD Protection >2000V per Method 3015.7 D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers ________________________________________________________________ Maxim Integrated Products 1 CMOS DECODERS/DRIVERS A0 A1 A2 A3 EN S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 S14 S15 S16 D V+ V- GND DG406 16-CHANNEL SINGLE-ENDED MULTIPLEXER 28 27 26 25 24 23 22 21 1 2 3 4 5 6 7 8 D V- S8 S7 S6 S5 S4 S3 S2 S1 EN A0 A1 A2 V+ N.C. N.C. S16 S15 S14 S13 S12 S11 S10 S9 GND N.C. A3 TOP VIEW 20 19 18 17 9 10 11 12 DIP/SO/TSSOP DG406 16 15 13 14 + _________________Pin Configurations 19-4729; Rev 6; 3/10 PART DG406CJ+ DG406CWI+ 0°C to +70°C 0°C to +70°C TEMP RANGE PIN-PACKAGE 28 Plastic DIP 28 Wide SO Ordering Information continued at end of data sheet. *Contact factory for dice specifications. +Denotes a lead(Pb)-free/RoHS-compliant package. DG406C/D 0°C to +70°C Dice* DG406DJ+ -40°C to +85°C 28 Plastic DIP DG406EWI+ -40°C to +85°C 28 Wide SO DG406DN+ -40°C to +85°C 28 PLCC DG406AK+ -55°C to +125°C 28 CERDIP Ordering Information _______________Functional Diagrams Functional Diagrams continued at end of data sheet. 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. Pin Configurations continued at end of data sheet. DG406EUI+ -40°C to +85°C 28 TSSOP D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers 2 _______________________________________________________________________________________ ABSOLUTE MAXIMUM RATINGS ELECTRICAL CHARACTERISTICS—Dual Supplies (V+ = 15V, V- = -15V, VGND = 0V, VAH = +2.4V, VAL = +0.8V, TA = TMIN to TMAX, unless otherwise noted.) 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. (Voltage Referenced to V-) V+ ............................................................................-0.3V, 44V GND.........................................................................-0.3V, 25V Digital Inputs, S, D (Note 1)....................(V- - 2V) to (V+ + 2V) or 30mA (whichever occurs first) Continuous Current (any terminal) ......................................30mA Peak Current, S or D (pulsed at 1ms, 10% duty cycle max) ..........................100mA Continuous Power Dissipation (TA = +70°C) 28-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ..727mW 28-Pin Wide SO (derate 12.50mW/°C above +70°C) ...1000mW 28-Pin PLCC (derate 10.53mW/°C above +70°C) ........842mW 28-Pin CERDIP (derate 16.67mW/°C above +70°C)...1333mW 28-Pin TSSOP (derate 12.8mW/°C above +70°C) ......1025mW Operating Temperature Ranges DG406/DG407C_ ...............................................0°C to +70°C DG406/DG407D_ ............................................-40°C to +85°C DG406/DG407AK ..........................................-55°C to +125°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (excluding dice; soldering, 10s) .......+300°C Soldering Temperature (reflow) Plastic DIP, Wide SO, TSSOP ......................................+260°C PLCC............................................................................+245°C CERDIP, Dice...............................................................+240°C VD = ±10V, VS = ±10V, sequence each switch on VD = +10V, VS = ±10V, VEN = 0V VD = +10V, VS = ±10V, VEN = 0V IS = -1.0mA, VD = ±10V IS = -1.0mA, VD = ±10V (Note 4) VD = ±10V, VS = +10V, VEN = 0V CONDITIONS nA -100 +100 ID(ON) + IS(ON) Drain-On Leakage Current (Note 5) -20 +20 -1 +0.02 +1 -200 +200 -40 +40 -1 +0.02 +1 nA -100 +100 ID(OFF) Drain-Off Leakage Current (Note 5) -20 +20 -1 +0.02 +1 -200 +200 60 100 -40 +40 -1 +0.02 +1 nA -50 +50 IS(OFF) Source-Off Leakage Current (Note 5) -5 +5 Ω 125 RDS(ON)Drain-Source On-Resistance 1.5 8 Ω 10 ΔRDS(ON) On-Resistance Matching Between Channels UNITSMIN TYP MAX(Note 2)SYMBOLPARAMETER Note 1: Signals on S_, D_, A0, A1, A2, A3, or EN exceeding V+ or V- are clamped by internal diodes. Limit forward current to max- imum current ratings. V-15 +15VANALOGAnalog Signal Range IS = -1.0mA, VD = ±5V or 0V 1.8 9 Ω 12 RFLATOn-Resistance Flatness (Note 3) TA = +25°C TA = TMIN to TMAX TA = +25°C TA = TMIN to TMAX TA = +25°C TA = TMIN to TMAX -0.5 +0.01 +0.5TA = +25°C TA = TMIN to TMAX TA = +25°C TA = TMIN to TMAX TA = +25°C TA = TMIN to TMAX TA = +25°C TA = TMIN to TMAX TA = +25°C TA = TMIN to TMAX DG407 DG406 DG407 DG406 C, D A C, D A C, D A C, D A C, D A SWITCH D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers _______________________________________________________________________________________ 3 ELECTRICAL CHARACTERISTICS—Dual Supplies (continued) (V+ = 15V, V- = -15V, VGND = 0V, VAH = +2.4V, VAL = +0.8V, TA = TMIN to TMAX, unless otherwise noted.) Off-Isolation (Note 6) dB-69VISO 2 15Q Charge Injection (Note 3) pC 55 150 ns 400 tON(EN)Enable Turn-On Time 130 200 ns10 40tOPENBreak-Before-Make Interval 110 300 µA-1.0 +1.0IAL Input Current with Input Voltage Low µA-1.0 +1.0IAH Input Current with Input Voltage High µA -10 +10 I-Negative Supply Current -1 +1 mA 1 I+Positive Supply Current 0.075 0.5 V±4.5 ±20Power-Supply Range 16 30 µA 75 UNITSMIN TYP MAX(Note 2)SYMBOLPARAMETER Crosstalk Between Channels VCT -92 dB Logic Input Capacitance CIN 8 pF Source-Off Capacitance CS(OFF) 8 pF 130 Drain-Off Capacitance CD(OFF) f = 1MHz, VEN = 0.8V, VD = 0V, Figure 8 65 pF 140 Drain-Source On Capacitance CD(ON) + CS(ON) f = 1MHz, VEN = 2.4V, VD = 0V, Figure 8 70 pF TA = +25°C VEN = 0V or 2.4V, VA = 0V TA = +25°C VA = 2.4V or 15V TA = +25°C TA = TMIN to TMAX TA = TMIN to TMAX TA = +25°C TA = +25°C TA = +25°C TA = TMIN to TMAX TA = +25°C TA = +25°C TA = +25°C TA = TMIN to TMAX CONDITIONS TA = +25°C TA = +25°C TA = +25°C TA = +25°C TA = +25°C VEN = 0V, RL = 1kΩ, f = 100kHz, Figure 6 CL = 1.0nF, VS = 0V, RS = 0Ω, Figure 5 Figure 3 VEN = 2.4V, VA(ALL) = 0V Figure 4 VEN = 2.4V, VA(ALL) = 0V VEN = VA = 0V or 5.0V VEN = 2.4V, f = 100kHz, VGEN = 1VP-P, RL = 1kΩ, Figure 7 f = 1MHz f = 1MHz, VEN = VS = 0V, Figure 8 DG406 DG407 DG406 DG407 ns 400 tTRANSTransition Time TA = TMIN to TMAX Figure 2 ns 300 tOFF(EN)Enable Turn-Off Time TA = TMIN to TMAX Figure 3 INPUT SUPPLY DYNAMIC D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers 4 _______________________________________________________________________________________ (Note 3) CONDITIONS CL = 1.0nF, VS1 = 0V, RS = 0Ω VAL = 0V, VS1 = 5V, Figure 3 VAL = 0V, VS1 = 5V, Figure 3 VS1 = 8V, VS16 = 0V, VA = 0V, Figure 2 IS = -1.0mA VD = 3V or 10V pC2 10Q Charge Injection (Note 3) ns80 300tOFF(EN) Enable Turn-Off Time (Note 3) V0 12VANALOGAnalog Signal Range ns105 600tON(EN) Enable Turn-On Time (Note 3) ns130 450tTRANS Transition Time (Note 3) Ω120 175RDS(ON)Drain-Source On-Resistance UNITSMIN TYP MAX(Note 2)SYMBOLPARAMETER ELECTRICAL CHARACTERISTICS—Single Supply (V+ = 12V, V- = 0V, VGND = 0V, VAH = +2.4V, VAL = +0.8V, TA = TMIN to TMAX, unless otherwise noted.) Note 2: The algebraic convention where the most negative value is a minimum and the most positive value a maximum is used in this data sheet. Note 3: Guaranteed by design. Note 4: ΔRON = RON(MAX) - RON(MIN). On-resistance match between channels and flatness are guaranteed only with specified voltages. Flatness is defined as the difference between the maximum and minimum value of on-resistance as measured at the extremes of the specified analog signal range. Note 5: Leakage parameters are 100% tested at the maximum-rated hot temperature and guaranteed by correlation at +25°C. Note 6: Off-isolation = 20log VD/VS, where VD = output and VS = input to off switch. TA = +25°C TA = +25°C TA = +25°C TA = +25°C TA = +25°C SWITCH DYNAMIC D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers _______________________________________________________________________________________ 5 120 140 160 ON-RESISTANCE vs. VD (DUAL SUPPLIES) 100 DG 40 6/ 7 TO C- 01 0 20 40 60 -20 20-15 15-10 10-5 50 80 VD (V) ±5V ±10V ±15V ±20V r D S (O N) (Ω ) 120 ON-RESISTANCE vs. VD AND TEMPERATURE (DUAL SUPPLIES) 100 DG 40 6/ 7 TO C- 02 0 20 40 60 -15 15-10 10-5 50 80 VD (V) +125°C +85°C +25°C -55°C r D S (O N) (Ω ) V+ = 15V V- = -15V 280 320 360 400 ON-RESISTANCE vs. VD (SINGLE SUPPLY) 240 DG 40 6/ 7 TO C- 03 40 80 120 160 15 201050 200 VD (V) r D S (O N) (Ω ) 5V 10V 15V 20V 120 140 160 ON-RESISTANCE vs. VD AND TEMPERATURE (SINGLE SUPPLY) 100 DG 40 6/ 7 TO C- 04 0 20 40 60 151050 80 VD (V) r D S (O N) (Ω ) +125°C +85°C +25°C -55°C V+ = 15V V- = 0V 30 CHARGE INJECTION vs. VD 20 DG 40 6/ 7 TO C- 07 -30 -20 -10 0 -15 15-10 10-5 50 10 VD (V) Q j (p C) V+ = 12V V- = 0V V+ = 15V V- = -15V 10 0.0001 -55 125 OFF LEAKAGE vs. TEMPERATURE 1 DG 40 6/ 7 TO C- 05 TEMPERATURE (°C) OF F LE AK AG E (n A) 25 0.01 0.001 -35 -15 65 0.1 100 1000 45 85 1055 INO (OFF) ICOM (ON) V+ = 15V V- = -15V 10 0.0001 -55 125 ON LEAKAGE vs. TEMPERATURE 1 DG 40 6/ 7 TO C- 06 TEMPERATURE (°C) ON L EA KA GE (n A) 25 0.01 0.001 -35 -15 65 0.1 100 1000 45 85 1055 ICOM (ON) V+ = 15V V- = -15V 100 0.001 -55 125 SUPPLY CURRENT vs. TEMPERATURE 10 DG 40 6/ 7 TO C- 08 TEMPERATURE (°C) I+ , I - ( μA ) 25 0.1 0.01 -35 -15 65 1 45 85 1055 I+ I- V+ = +15V V- = -15V VEN = VA = 0V, 4.5V __________________________________________Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) __________Applications Information Operation with Supply Voltages Other than ±15V Using supply voltages other than ±15V reduces the analog signal range. The DG406/DG407 switches oper- ate with ±4.5V to ±20V bipolar supplies or with a +5V to +30V single supply; connect V- to GND when operating with a single supply. Also, both device types can oper- ate with unbalanced supplies such as +24V and -5V. The Typical Operating Characteristics graphs show typical on-resistance with 20V, 15V, 10V, and 5V supplies. (Switching times increase by a factor of two or more for operation at 5V.) Overvoltage Protection Proper power-supply sequencing is recommended for all CMOS devices. Do not exceed the absolute maxi- mum ratings because stresses beyond the listed rat- ings may cause permanent damage to the devices. Always sequence V+ on first, then V-, followed by the logic inputs and analog signals. If power-supply sequencing is not possible, add two small signal diodes in series with supply pins for overvoltage pro- tection (Figure 1). Adding diodes reduces the analog signal range to 1V above V+ and 1V below V-, but low switch resistance and low leakage characteristics are unaffected. Device operation is unchanged, and the difference between V+ and V- should not exceed +44V. D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers 6 _______________________________________________________________________________________ Bidirectional OutputD28 Address InputsA3–A014–17 Enable InputsEN18 Bidirectional Analog Inputs S1–S819–26 Negative Supply Voltage InputV-27 GroundGND12 Bidirectional Analog Inputs S16–S94–11 DG406 PIN No Connection. Not internally connected. N.C.2, 3, 13 Positive Supply Voltage InputV+1 FUNCTIONNAME Negative Supply Voltage InputV-27 Bidirectional Output ADA28 GroundGND12 Address InputsA2, A1, A015, 16, 17 Enable InputEN18 Bidirectional Analog Inputs S1A–S8A19–26 Bidirectional Analog Inputs S8B–S1B4–11 No Connection. Not internally connected. N.C.3, 13, 14 DG407 PIN Bidirectional Output BDB2 Positive Supply Voltage InputV+1 FUNCTIONNAME _____________________________________________________________Pin Descriptions Vg S D V- V+ Figure 1. Overvoltage Protection Using External Blocking Diodes D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers _______________________________________________________________________________________ 7 ______________________________________________Test Circuits/Timing Diagrams 50% tTRANS tR < 20ns tF < 20ns VOUT +3V 0V VS1 0V VS16 LOGIC INPUT SWITCH OUTPUT +15V VOUT -15V GND V+ A1 V- A0 A2 A3 EN S1 S2-S15 S16 D ±10V +10V 50Ω DG406 300Ω 35pF +15V VOUT -15V GND V+ A1 V- A0 A2 EN S1B S1A-S8A S8B DB ±10V 50Ω DG407 300Ω 35pF 90% 90% tTRANS ON +10V 50% tOFF(EN) tR < 20ns tF < 20ns VOUT +3V 0V 0V LOGIC INPUT SWITCH OUTPUT +15V VOUT -15V GND V+ A1 V- A0 A2 A3 EN S1 S2-S16 D -5V 50Ω DG406 1kΩ 35pF 90% 10% tON(EN) +15V VOUT -15V GND V+ A1 V- A0 A2 EN S1B S1A-S16A S2B-S16B, DA DB -5V 50Ω DG407 1kΩ 35pF Figure 2. Transition Time Figure 3. Enable Switching Time D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers 8 _______________________________________________________________________________________ 50% tOPEN tR < 20ns tF < 20ns VOUT +3V 0V LOGIC INPUT SWITCH OUTPUT +15V VOUT -15V GND V+ A1 V- A0 A2 A3 EN S1-S16 D +5V 50Ω DG406 300Ω 35pF 80% +2.4V 0V ΔVOUT +3V 0V LOGIC INPUT +15V VOUT -15V GND V+ A1 V- A0 A2 A3 EN D DG406 CL = 1000nF VOUT S1-S16 CHANNEL SELECT RS VS ONOFF OFF ΔVOUT IS THE MEASURED VOLTAGE DUE TO CHARGE TRANSFER ERROR Q WHEN THE CHANNEL TURNS OFF. Q = CL = ΔVOUT _________________________________Test Circuits/Timing Diagrams (continued) Figure 4. Break-Before-Make Interval Figure 5. Charge Injection D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers _______________________________________________________________________________________ 9 +15V VOUT -15V GND V+ A1 V- A0 A2 A3 S16 D DG406 S1 RS = 50Ω VIN EN 10nF RL = 1kΩ OFF ISOLATION = 20log VOUT VIN 10nF +15V -15V GND V+ A1 V- A0 A2 A3 S16 COMDG406 S2 RS = 50Ω VOUT EN 10nF RL = 1kΩ CROSSTALK = 20log VOUT VIN 10nF S1 +15V -15V GND V+ A2 V- A3 A1 A0 S16DG406 CHANNEL SELECT S1 D EN Meter Impedance Analyzer f = 1MHz _________________________________Test Circuits/Timing Diagrams (continued) Figure 6. Off-Isolation Figure 7. Crosstalk Figure 8. Source/Drain Capacitance D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers 10 ______________________________________________________________________________________ ________Pin Configurations/Functional Diagrams/Truth Tables (continued) 28 27 26 25 24 23 22 21 1 2 3 4 5 6 7 8 DA V- S8A S7A S6A S5A S4A S3A S2A S1A EN A0 A1 A2 V+ DB N.C. S8B S7B S6B S5B S4B S3B S2B S1B GND N.C. N.C. TOP VIEW 20 19 18 17 9 10 11 12 DIP/SO DG407 16 15 13 14 A2 A1 A0 EN X 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 X 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 X 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 None 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 DG406 LOGIC “0” VAL ≤ 0.8V, LOGIC “1” = VAH ≥ 2.4V A3 X 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 A2 A1 A0 EN X 0 0 0 0 1 1 1 1 X 0 0 1 1 0 0 1 1 X 0 1 0 1 0 1 0 1 0 1 1 1 1 1 1 1 1 None 1 2 3 4 5 6 7 8 DG407 LOGIC “0” VAL ≤ 0.8V, LOGIC “1” = VAH ≥ 2.4V S7B S6B S5B S4B S3B S2B S1B S7A S6A S5A S4A S3A S2A S1A S8 B N .C . D B V+ D A V- S8 A G N D N .C . N .C . A2 A1 A0 EN PLCC 12 13 14 15 16 17 18 1234 262728 19 20 21 22 23 24 255 6 7 8 9 10 11 DG407 N.C. = NO INTERNAL CONNECTION D G 4 0 6 /D G 4 0 7 CMOS DECODERS/DRIVERS A0 A1 A2 EN S8B S7B S6B S5B S4B S3B S2B S1B S8A S7A S6A S5A S4A S3A S2A S1A DA V+ V- GND DB DG407 8-CHANNEL DIFFERENTIAL MULTIPLEXER _Ordering Information (continued) *Contact factory for dice specifications. +Denotes a lead(Pb)-free/RoHS-compliant package. __Functional Diagrams (continued) PART DG407CJ+ DG407CWI+ 0°C to +70°C 0°C to +70°C TEMP RANGE PIN-PACKAGE 28 Plastic DIP 28 Wide SO DG407C/D+ 0°C to +70°C Dice* DG407DJ+ -40°C to +85°C 28 Plastic DIP DG407EWI+ -40°C to +85°C 28 Wide SO DG407DN+ -40°C to +85°C 28 PLCC DG407AK -55°C to +125°C 28 CERDIP DG407EUI+ -40°C to +85°C 28 TSSOP Improved, 16-Channel/Dual 8-Channel, High-Performance, CMOS Analog Multiplexers ______________________________________________________________________________________ 11 PACKAGE TYPE PACKAGE CODE DOCUMENT NO. 28 PDIP P28+3 21-0044 28 Wide SO W28+6 21-0042 28 PLCC Q28+4 21-0049 28 TSSOP U28+2 21-0066 28 CERDIP J28+2 21-0046 Package Information For the latest package outline information and land patterns, 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. D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, CMOS Analog Multiplexers 12 ______________________________________________________________________________________ __________________________________________________________Chip Topographies GND S1 S2 S3 S4 S5 S6 S7 S8 EN A0 A1 A2 A3 N.C. 0.184" (4.67mm) 0.078" (1.98mm) S9 S10 S11 S12 S13 S14 S15 S16 N.C. V- D V+ GND S1A S2A S3A S4A S5A S6A S7A S8A EN A0 A1 A2 N.C. N.C. 0.184" (4.67mm) 0.078" (1.98mm) S1B S2B S3B S4B S5B S6B S7B S8B DB V- DA V+ SUBSTRATE IS INTERNALLY CONNECTED TO V+ SUBSTRATE IS INTERNALLY CONNECTED TO V+ DG406 DG407 N.C. = NO INTERNAL CONNECTION D G 4 0 6 /D G 4 0 7 Improved, 16-Channel/Dual 8-Channel, High-Performance, CMOS Analog Multiplexers 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 ti