CBM485AS8

CBM485 DATASHEET FEATURES GENERAL DESCRIPTION The CBM485 is low-power transceivers for  Low Quiescent Current: 300µA  -7V to +12V Common-Mode Input RS-485 Voltage Range contains one driver and one receiver. and RS-422 communication. IC The driver slew rates of the CBM485 is not  Three-State Outputs  50ns Propagation Delays, 5ns Skew  Half-Duplex Version Available  Operate from a Single 5V Supply and 500µA of supply current when unloaded  Allows up to 32 Transceivers on the Bus or fully loaded with disabled drivers. All parts  Data rate: 10 Mbps operate from a single 5V supply. Drivers are  Current-Limiting and Thermal Shutdown short-circuit current limited and are protected for Driver Overload Protection against  Enhanced ESD Specifications:  ±15kV IEC61000-4-2 Air Discharge  ±8kV IEC61000-4-2 Contact Discharge limited, allowing them to transmit up to 10 Mbps. These transceivers draw between 120µA Low power RS-485 systems  DTE/DCE interface  Packet switching  Local area networks (LNAs)  Data multiplexers  Data concentration  Integrated services digital network (ISDN) power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit. The CBM485 is designed APPLICATIONS  excessive for half-duplex applications. 1 www.corebai.com CBM485 DATASHEET Pin Description ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC) 12V Continuous Power Dissipation (TA= +70℃) Control Input Voltage -0.5V to (VCC + 0.5V) 8-Pin Plastic DIP (derate 9.09mW/°C above +70℃) 727mW Driver Input Voltage (DI) -0.5V to (VCC+ 0.5V) 8-Pin SOP (derate 5.88mW/℃ above +70℃) 471mW Driver Output Voltage (A, B) -8V to +12.5V Operating Temperature Ranges -40℃ to +125℃ Receiver Input Voltage (A, B) -8V to +12.5V Storage Temperature Range -65℃ to +160℃ Receiver Output Voltage (RO) -0.5V to (VCC+0.5V) Lead Temperature (soldering, 10sec) +300℃ * 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 under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. 2 www.corebai.com CBM485 DATASHEET DC ELECTRICAL CHARACTERISTICS (VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL Differential Driver Output (no load) VOD1 Differential Driver Output (with load) VOD2 CONDITIONS R = 50Ω (RS-422) MIN TYP MAX UNITS 5 V 2 R = 27Ω (RS-485), Figure 1 1.5 5 V Change in Magnitude of Driver Differential Output Voltage for ∆VOD R = 27Ω or 50Ω, Figure 1 0.2 V VOC R = 27Ω or 50Ω, Figure 1 3 V ∆VOC R = 27Ω or 50Ω, Figure 1 0.2 V Complementary Output States Driver Common-Mode Output Voltage Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States Input High Voltage VIH DE, DI, RE Input Low Voltage VIL DE, DI, RE 0.8 V Input Current IIN1 DE, DI, RE ±2 μA Input Current (A, B) IIN2 Receiver Differential Threshold 2.0 V DE = 0V; VIN = 12V 1.0 VCC = 0V or 5.25V VIN = -7V -0.8 VTH -7V ≤ VCM ≤12V Receiver Input Hysteresis ∆VTH VCM = 0V Receiver Output High Voltage VOH IO = -4mA, VID = 200mV Receiver Output Low Voltage VOL IO = 4mA, VID = -200mV 0.4 V IOZR 0.4V ≤ VO ≤ 2.4V ±1 μA RIN -7V ≤ VCM ≤ 12V Voltage Three-State (high impedance) Output Current at Receiver Receiver Input Resistance No-Load Supply Current (Note 3) ICC -0.2 0.2 mA 70 V mV 3.5 V 12 kΩ DE = VCC 500 900 RE = 0V or VCC 300 500 μA DE = 0V Driver Short-Circuit Current VO = High Driver Short-Circuit Current VO = Low Receiver Short-Circuit Current ESD Protection IOSD1 -7V ≤ VO ≤ 12V (Note 4) 35 250 mA IOSD2 -7V ≤ VO ≤12V (Note 4) 35 250 mA IOSR 0V ≤ VO ≤ VCC 7 95 mA A, B, Y and Z pins, tested using Human Body Model 15 3 www.corebai.com kV CBM485 DATASHEET SWITCHING CHARACTERISTICS (VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS tPLH RDIFF = 54 10 55 60 tPHL CL1 = CL2 = 100pF 10 55 60 Driver Output Skew to Output tSKEW RDIFF = 54 5 10 ns Driver Enable to Output High tZH CL= 100pF, S2 closed 40 70 ns Driver Enable to Output Low tZL CL= 100pF, S1 closed 40 70 ns Driver Disable Time from Low tLZ CL= 15pF, S1 closed 40 70 ns Driver Disable Time from High tHZ CL= 15pF, S2 closed 40 70 ns tPLH RDIFF = 54 20 60 100 tPHL CL1 = CL2 = 100pF 20 60 100 5 10 ns Driver Input to Output Receiver Input to Output , CL1 = CL2 = 100pF RDIFF = 54 ns ns | tPLH - tPHL | Differential Receiver Skew tSKD Receiver Enable to Output Low tZL CRL = 15pF, S1 closed 30 50 ns Receiver Enable to Output High tZH CRL = 15pF, S2 closed 30 50 ns Receiver Disable Time from Low tLZ CRL = 15pF, S1 closed 30 50 ns Receiver Disable Time from High tHZ CRL = 15pF, S2 closed 30 50 ns Maximum Data Rate fMAX 10 20 Mbps CL1 = CL2 = 100pF 2.5 Note 1: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified. Note 2: All typical specifications are given for VCC=5V and TA=+25℃. Note 3: Supply current specification is valid for loaded transmitters when DE=0V. Note 4: Applies to peak current. 4 www.corebai.com CBM485 DATASHEET TEST CIRCUITS Figure 1. Driver VOD and VOC Figure 2. Driver VOD with Varying Common-Mode Voltage Figure 3. Receiver VOH and VOL Figure 4. Driver Differential Output Delay and Transition Times 5 www.corebai.com CBM485 DATASHEET Figure 5. Driver Propagation Times Figure 6. Driver Enable and Disable Times (tPZH, tPSH, tPHZ) Figure 7. Driver Enable and Disable Times (tPZL, tPSL, tPLZ) 6 www.corebai.com CBM485 DATASHEET Figure 8. Receiver Propagation Delay Figure 9. Receiver Enable and Disable Times Note 5: The input pulse is supplied by a generator with the following characteristics: PRR = 250kHz, 50% duty cycle, tr≤6.0ns, ZO = 50Ω. Note 6: CL includes probe and stray capacitance. 7 www.corebai.com CBM485 DATASHEET Function Tables X-don’t care Z-high impedance Transmitting INPUTS Receiving OUTPUTS X INPUTS OUTPUTS RE DE DI Z Y RE DE A-B RO X 1 1 0 1 0 0 +2.0V 1 X 1 0 1 0 0 0 -2.0V 0 0 0 X Z Z 0 0 open 1 1 0 X Z Z 1 0 X Z Typical Information Figure 10. CBM485 Typical RS-485 Network 8 www.corebai.com CBM485 DATASHEET Driver Output Protection Excessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range. In addition, a thermal shutdown circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively. Propagation Delay Skew time is simply the difference between the low-to-high and high-to-low propagation delay. Small driver/receiver skew times help maintain a symmetrical mark-space ratio (50% duty cycle). The receiver skew time, |tPRLH - tPRHL|, is under 10ns. The driver skew times are 5ns for the CBM485. Typical Applications CBM485 transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figure 10 shows typical network applications circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet. To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possible. 9 www.corebai.com CBM485 DATASHEET PACKAGE NOTES: 1. Dimensions A and B do not include mold flash or protrusion. 2. Maximum mold flash or protrusion 0.15 mm (0.006) per side for A; for B ‑ 0.25 mm (0.010) per side. Symbol Dimensions ,mm Min Max A 4.8 5 B 3.8 4 C 1.35 1.75 D 0.33 0.51 F 0.4 1.27 G 1.27 H 5.72 J 0° 8° K 0.1 0.25 M 0.19 0.25 P 5.8 6.2 R 0.25 0.5 10 www.corebai.com CBM485 DATASHEET PACKAGE/ORDERING INFORMATION PRODUCT ORDERING NUMBER TEMPRANGE PACKAGE PAKEAGE TRANSPOT MARKING MEDIA,QUANTILY CBM485AS8 -40℃~125℃ SOIC-8(SOP8) CBM485A Tape and Reel,2500 CBM485ACS8 -0℃~70℃ SOIC-8(SOP8) CBM485C Tape and Reel,2500 CBM485 11 www.corebai.com