19-1940; Rev 0; 4/01
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces
_________________General Description
The MAX1480EA/MAX1480EC/MAX1490EA/MAX1490EB are complete, electrically isolated, RS-485/RS-422 data communications interface solutions in a hybrid microcircuit. The RS-485/RS-422 I/O pins are protected against ±15kV electrostatic discharge (ESD) shocks, without latchup. Transceivers, optocouplers, and a transformer provide a complete interface in a standard DIP package. A single +5V supply on the logic side powers both sides of the interface. The MAX1480EC/MAX1490EB feature reduced-slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission at data rates up to 160kbps. The MAX1480EA/MAX1490EA driver slew rate is not limited, allowing transmission rates up to 2.5Mbps. The MAX1480EA/MAX1480EC are designed for half-duplex communication, while the MAX1490EA/MAX1490EB feature full-duplex communication. Drivers are short-circuit current limited and protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a highimpedance state. The receiver input has a fail-safe www.DataSheet4U.com feature that guarantees a known output (RO low for the MAX1480EA/MAX1480EC, RO high for the MAX1490EA/ MAX1490EB) if the input is open circuit. The MAX1480EA/MAX1480EC/MAX1490EA/MAX1490EB withstand 1260VRMS (1min) or 1520VRMS (1s). Their isolated outputs meet all RS-485/RS-422 specifications. The MAX1480EA/MAX1480EC are available in a 28-pin DIP package, and the MAX1490EA/MAX1490EB are available in a 24-pin DIP package. .
____________________________Features
o Isolated Data Interface, Guaranteed to 1260VRMS (1min) o ±15kV ESD Protection on I/O Pins o Slew-Rate Limited for Errorless Data Transmission (MAX1480EC/MAX1490EB) o High-Speed, Isolated, 2.5Mbps RS-485/RS-422 Interface (MAX1480EA/MAX1490EA) o Full-Duplex Data Communication (MAX1490EA/MAX1490EB) o Single +5V Supply o Current Limiting and Thermal Shutdown for Driver Overload Protection o Standard 0.6in DIP Packages 28-Pin DIP (MAX1480EA/MAX1480EC) 24-Pin DIP (MAX1490EA/MAX1490EB)
MAX1480E/MAX1490E
_______________Ordering Information
PART† MAX1480EACPI MAX1480EAEPI TEMP. RANGE 0°C to +70°C -40°C to +85°C PIN-PACKAGE 28 Wide Plastic DIP* 28 Wide Plastic DIP*
Ordering Information continued at end of data sheet. † Data rate for A parts is up to 2.5Mbps. Data rate for C parts is up to 250kbps. *See Reliability section at end of data sheet.
Pin Configurations
TOP VIEW
VCC1 VCC2 D1 D2 GND1 1 2 3 4 5
MAX845E MAX488E MAX490E
24 AC1 23 AC2
________________________Applications
Isolated RS-485/RS-422 Data Interface Transceivers for EMI-Sensitive Applications Industrial-Control Local Area Networks Automatic Test Equipment HVAC/Building Control Networks Telecom
MAX1490EA/ MAX1490EB
22 ISO VCC1 21 ISO RO DRV 20 A 19 B 18 Z 17 Y 16 ISO COM1 15 ISO DI DRV 14 ISO VCC2 13 ISO RO LED ISOLATION BARRIER
FS 6 SD 7
VCC3 8 DI 9
VCC4 10 RO 11 GND2 12
DIP Selector Guide appears at end of data sheet. Pin Configurations continued at end of data sheet. 1
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces MAX1480E/MAX1490E
ABSOLUTE MAXIMUM RATINGS
With Respect to GND_ Supply Voltage (VCC_)..........................................-0.3V to +6V Control Input Voltage (SD, FS)..............-0.3V to (VCC_ + 0.3V) Receiver Output Voltage (RO, RO).......-0.3V to (VCC_ + 0.3V) Output Switch Voltage (D1, D2).......................................+12V With Respect to ISO COM_ Control Input Voltage (ISO DE_) ....-0.3V to (ISO VCC_ + 0.3V) Driver Input Voltage (ISO DI_) .......-0.3V to (ISO VCC_ + 0.3V) Receiver Output Voltage (ISO RO_) ..-0.3V to (ISO VCC_ + 0.3V) Driver Output Voltage (A, B, Y, Z) ......................-8V to +12.5V Receiver Input Voltage (A, B).............................-8V to +12.5V LED Forward Current (DI, DE, ISO RO LED) ......................50mA Continuous Power Dissipation (TA = +70°C) 24-Pin Plastic DIP (derate 8.7mW°C above +70°C) ....696mW 28-Pin Plastic DIP (derate 9.09mW/°C above +70°C) .727mW Operating Temperature Ranges MAX1480E_CPI/MAX1490E_CPI ........................0°C to +70°C MAX1480E_EPI/MAX1490E_EPI ......................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C
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
(VCC_ = +5V ±10%, VFS = VCC_, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC_ = +5V and TA = +25°C.) (Notes 1, 2) PARAMETER Switch Frequency SYMBOL fSWL fSWH VFS = 0 FS = VCC_ or open MAX1480EA, DE´ = VCC_ or open MAX1480EC, DE´ = VCC_ or open MAX1490EA MAX1490EB Shutdown Supply Current (Note 3) Shutdown Input Threshold Shutdown Input Leakage Current FS Input Threshold FS Input Pullup Current FS Input Leakage Current Input High Voltage Input Low Voltage Isolation Voltage Isolation Resistance Isolation Capacitance Differential Driver Output (No Load) Differential Driver Output (with Load) VIH VIL VISO RISO CISO VOD1 VOD2 R = 50Ω (RS-422) R = 27Ω (RS-485), Figure 4 2 1.5 VFSH VFSL High Low FS low FS high DE´, DI´, Figures 1 and 2 DE´, DI´, Figures 1 and 2 TA = +25°C, 1min (Note 4) TA = +25°C, VISO = 50VDC TA = +25°C, f = 1MHz 1260 100 10,000 10 8 VCC - 0.4 0.4 2.4 0.8 50 10 ISHDN VSDH VSDL SD = VCC_ High Low 2.4 0.8 10 RL = ∞ RL = 54Ω RL = ∞ RL = 54Ω RL = ∞ RL = 54Ω RL = ∞ RL = 54Ω CONDITIONS MIN TYP 535 725 85 145 55 120 130 180 65 130 0.2 120 120 180 125 mA MAX UNITS kHz mA
Operating Supply Current
ICC
µA V pA V µA pA V V VRMS MΩ pF V V
5
2
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±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces MAX1480E/MAX1490E
ELECTRICAL CHARACTERISTICS (continued)
(VCC_ = +5V ±10%, VFS = VCC_, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC_ = +5V and TA = +25°C.) (Notes 1, 2) PARAMETER Change in Magnitude of Driver Output Voltage for Complementary Output States Driver Common-Mode Output SYMBOL ∆VOD VOC CONDITIONS Differential R = 27Ω or 50Ω, Figure 4 Common mode R = 27Ω or 50Ω, Figure 4 MAX1490EA/ MAX1490EB MAX1480EA/ MAX1480EC MAX1490EA/ MAX1490EB MAX1480EA/ MAX1480EC (MAX1480E_) (MAX1490E_) 48 12 -0.2 70 0.4 250 100 ±15 0.2 0.3 4 1.0 0.25 mA 0.8 0.2 kΩ V mV V µA mA kV V MIN TYP MAX 0.3 V UNITS
VIN = +12V Input Current (A, B) ISO IIN DE´ = 0, VCC_ = 0 or +5.5V VIN = -7V
Receiver Input Resistance Receiver Differential Threshold Receiver Input Hysteresis Receiver Output Low Voltage Receiver Output High Current Driver Short-Circuit Current ESD Protection
RIN VTH ∆VTH VOL IOH ISO IOSD ISO IOSD
-7V ≤ VCM ≤ +12V -7V ≤ VCM ≤ +12V VCM = 0
Using resistor values listed in Tables 1 and 2 VOUT = 5.5V -7V ≤ VO ≤ 12V (Note 5) A, B, Y, and Z pins, tested using Human Body Model, Figures 1 and 2
SWITCHING CHARACTERISTICS—MAX1480EA/MAX1490EA
(VCC_ = +5V ±10%, VFS = VCC_, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC_ = +5V and TA = +25°C.) PARAMETER Driver Input to Output Propagation Delay Driver Output Skew Driver Rise or Fall Time Driver Enable to Output High (MAX1480EA Only) Driver Enable to Output Low (MAX1480EA Only) Driver Disable Time from Low (MAX1480EA Only) Driver Disable Time from High (MAX1480EA Only) Receiver Input to Output Propagation Delay SYMBOL tPLH tPHL tSKEW tR, tF tZH tZL tLZ tHZ tPLH tPHL CONDITIONS Figures 5 and 7, RDIFF = 54Ω, CL1 = CL2 = 100pF Figures 5 and 7, RDIFF = 54Ω, CL1 = CL2 = 100pF Figures 5 and 7, RDIFF = 54Ω, CL1 = CL2 = 100pF Figures 6 and 8, CL = 100pF, S2 closed Figures 6 and 8, CL = 100pF, S1 closed Figures 6 and 8, CL = 15pF, S1 closed Figures 6 and 8, CL = 15pF, S2 closed Figures 5 and 10, RDIFF = 54Ω, CL1 = CL2 = 100pF MIN TYP 90 60 30 15 1.0 1.0 0.5 0.5 120 90 MAX 275 275 100 50 1.8 1.8 1.8 1.8 225 225 UNITS ns ns ns µs µs µs µs ns
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3
±15kV ESD-Protected, Isolated RS-485/RS-422 Data Interfaces MAX1480E/MAX1490E
SWITCHING CHARACTERISTICS—MAX1480EA/MAX1490EA (continued)
(VCC_ = +5V ±10%, VFS = VCC_, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC_ = +5V and TA = +25°C.) PARAMETER |tPLH - tPHL| Differential Receiver Skew Maximum Data Rate Time to Shutdown Shutdown to Driver Output High Shutdown to Driver Output Low SYMBOL tSKD fMAX tSHDN tZH(SHDN) tZH(SHDN) CONDITIONS Figures 5 and 10, RDIFF = 54Ω, CL1 = CL2 = 100pF tSKEW, tSKD, tPHL ≤ 25% of data period Figures 6 and 9, CL = 100pF, S2 closed Figures 6 and 9, CL = 100pF, S1 closed 2.5 100 3 3 15 15 MIN TYP 30 MAX 150 UNITS ns Mbps µs µs µs
SWITCHING CHARACTERISTICS—MAX1480EC/MAX1490EB
(VCC_ = +5V ±10%, VFS = VCC_, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC_ = +5V and TA = +25°C.) PARAMETER Driver Input to Output Propagation Delay Driver Output Skew Driver Rise or Fall Time Driver Enable to Output High (MAX1480EC Only) Driver Enable to Output Low (MAX1480EC Only) Driver Disable Time from Low (MAX1480EC Only) Driver Disable Time from High (MAX1480EC Only) Receiver Input to Output Propagation Delay
