CBM3485AS8

CBM3485 DATASHEET FEATURES  Low Quiescent Current: 300µA  -7V to +12V Common-Mode Input Voltage Range  Three-State Outputs  80ns Propagation Delays, 5ns Skew  Half-Duplex Versions Available  Operate from a Single 3.3V Supply  Allows up to 32 Transceivers on the Bus  Data rate: 10 Mbps  Current-Limiting and Thermal Shutdown for Driver Overload Protection  Enhanced ESD Specifications: ±15kV IEC61000-4-2 Air Discharge ±8kV IEC61000-4-2 Contact Discharge GENERAL DESCRIPTION The CBM3485is low-power transceivers for RS-485 and RS- 422 communication. IC contains one driver and one receiver. The driver slew rates of the CBM3485 is not limited, allowing them to transmit up to 10Mbps. These transceivers draw between 120µA and 500µA of supply current when unloaded or fully loaded with disabled drivers. All parts operate from a single 3.3V supply. Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a failsafe feature that guarantees a logic-high output if the input is open circuit. 1 www.corebai.com CBM3485 DATASHEET Pin Description Figure 2 ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC) 7V Continuous Power Dissipation (TA= +70℃) Control Input Voltage -0.3V to 7V 8-Pin Plastic DIP (derate 9.09mW/℃ above+70℃) 727mW Driver Input Voltage (DI) -0.3V to 7V 8-Pin SOP (derate 5.88mW/℃ above +70℃) 471mW Driver Output Voltage (A, B) -7.5V to +12.5V Operating Temperature Ranges -40℃ to +125℃ Receiver Input Voltage (A, B) -7.5V to +12.5V Storage Temperature Range -65°C to +160℃ Receiver Output Voltage (RO) -0.3V to Lead Temperature (soldering, 10sec) +300℃ (VCC+0.3V) * 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 CBM3485 DATASHEET Electrical Parameters (VCC = 3.3V ±0.3V, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER Differential Driver Output (no load) Differential Driver Output (with load) SYMBOL CONDITIONS MIN TYP VOD1 VOD2 R = 100Ω (RS-422) R=54Ω (RS-485), Figure 4 MAX UNITS 3 V 1 V 0.8 Change in Magnitude of Driver Differential Output Voltage for ∆VOD R = 54Ω or 50Ω, Figure 4 0.2 V VOC R = 54Ω or 100Ω, Figure 4 2 V ∆VOC R = 54Ω or 100Ω, Figure 4 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 Voltage VTH 2.0 V DE = 0V; VIN=12V 1.0 VCC=0Vor 3.35V VIN=-7V -0.8 -7V ≤ VCM ≤12V -0.2 0.2 V Receiver Input Hysteresis ∆VTH VCM = 0V Receiver Output High Voltage VOH IO = -1.5mA, VID = 200mV Receiver Output Low Voltage VOL IO = 2.5mA, VID = -200mV 0.4 V IOZR 0.4V ≤ VO ≤ 2.4V ±1 µA RIN -7V ≤ VCM ≤ 12V Three-State (high impedance) Output Current at Receiver Receiver Input Resistance No-Load Supply Current (Note 3) ICC 70 mA mV 2.5 V 12 kΩ DE = VCC 500 800 RE = 0V or VCC 300 400 DE = 0V Driver Short-Circuit Current, VO = High Driver Short-Circuit Current VO = Low Receiver Short-Circuit Current ESD Protection μA IOSD1 -7V≤VO≤12V (Note 4) 250 mA IOSD2 -7V≤VO≤12V (Note 4) 250 mA IOSR 0V ≤ VO ≤ VCC 95 mA A, B, Y and Z pins, tested using Human Body Model ±6.5 ±15 3 www.corebai.com kV CBM3485 DATASHEET SWITCHING CHARACTERISTICS (VCC = 3.3V ±0.3V, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS tPLH RDIFF = 54Ω 10 80 100 tPHL CL1 = CL2 = 100pF 10 80 100 Driver Output Skew to Output tSKEW RDIFF = 54,CL1=CL2= 100pF 5 10 ns Driver Enable to Output High tZH CL= 100pF, S2 closed 55 80 ns Driver Enable to Output Low tZL CL= 100pF, S1 closed 55 80 ns Driver Disable Time from Low tLZ CL= 15pF, S1 closed 60 90 ns Driver Disable Time from High tHZ CL= 15pF, S2 closed 60 90 ns | tPLH - tPHL | Differential tSKD RDIFF = 54Ω 13 20 ns tPLH RDIFF = 54Ω 20 120 200 tPHL CL1 = CL2 = 100pF 20 120 200 CL1 = CL2 = 100pF 5 10 Driver Input to Output Receiver Input to Output Receiver Skew | tPLH - tPHL | ns ns Receiver Enable to Output Low tZL CRL = 15pF, S1 closed 50 90 ns Receiver Enable to Output High tZH CRL = 15pF, S2 closed 50 90 ns Receiver Disable Time from Low tLZ CRL = 15pF, S1 closed 40 80 ns Receiver Disable Time from High tHZ CRL = 15pF, S2 closed 40 80 ns Maximum Data Rate fMAX 10 Mbps 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=3.3V 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 CBM3485 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 CBM3485 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 CBM3485 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 CBM3485 DATASHEET Function Tables Transmitting INPUTS Receiving OUTPUTS X INPUTS OUTPUTS RE DE DI Z Y RE DE A-B RO X 1 1 0 1 0 0 +0.2V 1 X 1 0 1 0 0 0 -0.2V 0 0 0 X Z Z 0 0 open 1 1 0 X Z Z 1 0 X Z X-don’t care Z-high impedance Typical Information Figure 10. CBM3485 Typical RS-485 Network 8 www.corebai.com CBM3485 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 CBM3485. Typical Applications CBM3485 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 CBM3485 DATASHEET PACKAGE NOTES: 1. Dimensions “A”, “B” do not include mold flash or protrusions. Maximum mold flash or protrusions 0.25 mm (0.010) per side. Symbol Dimensions ,mm Min Max A 8.51 10.16 B 6.1 7.11 C 5.33 D 0.36 0.56 F 1.14 1.78 G 2.54 H 7.62 J 0° 10° K 2.92 3.81 L 7.62 8.26 M 0.2 0.36 N 0.38 10 www.corebai.com CBM3485 DATASHEET 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 11 www.corebai.com CBM3485 DATASHEET PACKAGE/ORDERING INFORMATION PRODUCT ORDERING PAKEAGE TRANSPOT MARKING MEDIA,QUANTILY SOIC-8(SOP8) CBM3485A Tape and Reel,2500 SOIC-8(SOP8) CBM3485AC Tape and Reel,2500 TEMPRANGE PACKAGE CBM3485AS -40℃~125℃ CBM3485ACS -0℃~70℃ NUMBER CBM3485 12 www.corebai.com