±15kV ESD-Protected, EMC-Compliant, 230kbps RS-232 Serial Port for Modems

Transcription

1 19-177; Rev ; 9/96 ±15k ES-Protected, EMC-Compliant, 23kbps General escription The is a complete CE RS-232 serial port designed to meet the stringent ES requirements of the European community. All transmitter outputs and receiver inputs are protected to ±15k using IEC Air-Gap ischarge, ±8k using IEC Contact ischarge, and ±15k using the Human Body Model. The has five RS-232 transmitters, three RS- 232 receivers, and no charge pump, optimizing it for operation in modem applications. It is guaranteed to run at data rates up to 23kbps, providing compatibility with popular software for communicating with personal computers. Power-supply current is less than 3µA for I and ISS, and less than 1mA for ICC. The is available in an SO package and in the tiny SSOP that further reduces board space. Applications Modems ISN Modems Instruments Equipment Meeting IEC1-4-2 Features Enhanced ES Protection: ±15k Human Body Model ±8k IEC1-4-2, Contact ischarge ±15k IEC1-4-2, Air-Gap ischarge Latchup Free uring an ES Event 2-Pin SSOP or SO Packages Guaranteed 23kbps ata Rate Flow-Through Pinout Complete CE Serial Port Ordering Information PART TEMP. RANGE PIN-PACKAGE CWP CAP C to +7 C C to +7 C 2 SO 2 SSOP EWP -4 C to +85 C 2 SO EAP -4 C to +85 C 2 SSOP Typical Operating Circuit Pin Configuration T R1 TOP IEW T1OUT CC T1IN TTL/CMOS LOGIC I/O T2 T3 T4 T5 RS-232 INTERCONNECTING CABLE R2 R3 R4 R5 TTL/CMOS LOGIC I/O R1IN T2OUT R2IN R3IN T3OUT T4OUT R1OUT T2IN R2OUT R3OUT T3IN T4IN R1 T1 T5OUT 9 12 T5IN R2 T2 SS 1 11 GN R3 T3 SO/SSOP Maxim Integrated Products 1 For free samples & the latest literature: or phone

2 ±15k ES-Protected, EMC-Compliant, 23kbps ABSOLUTE IMUM RATINGS CC to to +14 SS to -14 Input oltages T IN to +6 R IN...±3 Output oltages T OUT...±15 R OUT to ( CC +.3) Short-Circuit uration T OUT (one at a time)...continuous R OUT (one at a time)...continuous Continuous Power issipation (T A = +7 C) Wide SO (derate 1.mW/ C above +7 C)...8mW SSOP (derate 8.mW/ C above +7 C)...64mW Operating Temperature Ranges C_P... C to +7 C E_P...-4 C to +85 C Storage Temperature Range C to +16 C Lead Temperature (soldering, 1sec)...+3 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 ( CC = +4.5 to +5.5, = +1.8 to +13.2, SS = -1.8 to -13.2, T A = T to T, unless otherwise noted. Typical values are at T A = +25 C.) PARAMETER C CHARACTERISTICS Operating oltage Range Supply Current LOGIC Input Logic Threshold Low Input Logic Threshold High Input Leakage Current Output oltage Low Output oltage High TRANSMITTER OUTPUTS Output oltage Swing Transmitter Output Resistance RS-232 Output Short-Circuit Current RECEIER INPUTS Receiver Input oltage Operating Range RS-232 Input Threshold Low RS-232 Input Threshold High RS-232 Input Hysteresis RS-232 Input Resistance Receiver Output Short-Circuit Current SYMBOL I CC No load 23 1 I No load µa I SS No load OLR OHR T IN T IN R OUT; I SINK = 3.2mA R OUT; I SOURCE = 1mA CONITIONS CC SS ILT IHT = 7., SS = -7., R L = 3kΩ = 12, SS = -12, R L = 3kΩ CC = = SS =, T_OUT = ±2 TYP 2. CC -.6 ±5. ± ±35 ± ±1 UNITS µa Ω ma kω ma 2

3 ±15k ES-Protected, EMC-Compliant, 23kbps ELECTRICAL CHARACTERISTICS (continued) ( CC = +4.5 to +5.5, = +1.8 to +13.2, SS = -1.8 to -13.2, T A = T to T, unless otherwise noted. Typical values are at T A = +25 C.) PARAMETER ES CHARACTERISTICS ES Protection TIG CHARACTERISTICS Transmitter Output Propagation elay, Low to High Transmitter Output Propagation elay, High to Low Transmitter Propagation elay Skew, t PLHT - t PHLT Transition Output Slew Rate Receiver Output Propagation elay, Low to High Receiver Output Propagation elay, High to Low Receiver Propagation elay Skew, t PLHR - t PHLR Guaranteed ata Rate SYMBOL CONITIONS Human Body Model IEC1-4-2 (Contact ischarge) IEC1-4-2 (Air-Gap ischarge) TYP ±15 ±8 ±15 UNITS = 12, SS = -12, R L = 3kΩ, t PLHT 4 µs C L = 1pF, T A = +25 C = 12, SS = -12, R L = 3kΩ, t PHLT 4 µs C L = 1pF, T A = +25 C = 12, SS = -12, R L = 3kΩ, t SKT.4 µs C L = 1pF, T A = +25 C SR = 12, SS = -12, R L = 3kΩ to 7kΩ, measured from +3 to -3 or -3 to +3, Figure 3, T A = +25 C C L = 15pF to 25pF C L = 5pF to 1pF t PLHR CC = 5, C L = 5pF, T A = +25 C 4. µs t PHLR CC = 5, C L = 5pF, T A = +25 C 4. µs t SKR CC = 5, C L = 5pF, T A = +25 C.4 µs R CC = 5, = 12, C L = 5pF to SS = -12, 25pF 12 R L = 3kΩ to 7kΩ, C L = 5pF to T A = +25 C 1pF 23 k /µs kbps 3

4 ±15k ES-Protected, EMC-Compliant, 23kbps Typical Operating Characteristics ( CC = +5., = +12., SS = -12., T A = +25 C, unless otherwise noted.) SUPPLY CUREENT (ma) SUPPLY CURRENT vs. SUPPLY OLTAGE 25 I, 24kbps 2 15 I, 12kbps 1 I, 2kbps 5 1 TRANSMITTER AT ATA RATE I CC 4 TRANSMITTERS AT ATA RATE / 16 3kΩ + 25pF LOA -5 I SS, 2kbps -1 I SS, 12kbps -15 I SS, 24kbps SUPPLY OLTAGE () -TOC1 SUPPLY CUREENT (ma) SUPPLY CURRENT vs. LOA CAPACITANCE 25 2 I, 24kbps 15 I, 12kbps 1 I, 2kbps 5 1 TRANSMITTER AT ATA RATE I CC 4 TRANSMITTERS AT ATA RATE / 16 3kΩ + C L LOA -5 I SS, 2kbps -1 I SS, 12kbps -15 I SS, 24kbps LOA CAPACITANCE (pf) -TOC2 SLEW RATE (/µs) SLEW RATE vs. LOA CAPACITANCE FALL RISE 1 TRANSMITTER 24kbps 4 TRANSMITTERS 15kbps 3kΩ + C L LOA LOA CAPACITANCE (pf) -TOC3 TRANSMITTER OUTPUT OLTAGE () TRANSMITTER OUTPUT OLTAGE vs. LOA CAPACITANCE 12kbps 24kbps 1 TRANSMITTER AT ATA RATE 4 TRANSMITTERS AT ATA RATE / 16 3kΩ + C L LOA 24kbps 12kbps -TOC4 SLEW RATE (/µs) TRANSMITTER OUTPUT OLTAGE vs. LOA CURRENT PER TRANSMITTER CC T1 T2 T3 OUT+ OUT- OUT+ OUT- -TOC5 SLEW RATE (/µs) RISE, 2pF SLEW RATE vs. TEMPERATURE FALL, 5pF FALL, 2pF RISE, 5pF -TOC LOA CAPACITANCE (pf) LOA CURRENT PER TRANSMITTER (pf) TEMPERATURE ( C) 4

5 ±15k ES-Protected, EMC-Compliant, 23kbps Pin escription PIN NAME FUNCTION 1 Supply-oltage Input, +1.8 to , 4, 7, 8, 9 T1OUT T5OUT Transmitter Outputs, swing between and SS 3, 5, 6 R1IN, R2IN, R3IN Receiver Inputs 1 SS Supply-oltage Input, -1.8 to GN Ground. Connect to system ground. 12, 13, 14, 17, 19 T5IN T1IN Transmitter Inputs 15, 16, 18 R3OUT, R2OUT, R1OUT Receiver Outputs, swing between GN and CC 2 CC Supply-oltage Input, +4.5 to +5.5 HIGH- OLTAGE C SOURCE R C 5M to 1M CHARGE-CURRENT LIMIT RESISTOR Cs 15pF R 33Ω ISCHARGE RESISTANCE STORAGE CAPACITOR Figure 1a. IEC1-4-2 ES Test Model IPEAK I 1% 9% EICE UNER TEST etailed escription ±15k ES Protection As with all Maxim devices, ES-protection structures are incorporated on all pins to protect against electrostatic discharges encountered during handling and assembly. The driver outputs and receiver inputs have extra protection against static electricity found in normal operation. Maxim s engineers developed state-of-the-art structures to protect these pins against ES of ±15k, without damage. After an ES event, the continues working without latchup. ES protection can be tested in several ways. The transmitter outputs and the receiver inputs are characterized for protection to the following: 1) ±15k using the Human Body Model 2) ±8k using the Contact-ischarge Method specified in IEC1-4-2 (formerly IEC81-2) 3) ±15k using the Air-Gap Method specified in IEC1-4-2 (formerly IEC81-2) ES Test Conditions ES performance depends on a number of conditions. Contact Maxim for a reliability report that documents test setup, methodology, and results. 1% t r =.7ns to 1ns 3ns 6ns t Figure 1b. IEC1-4-2 ES Generator Current Waveform 5

6 ±15k ES-Protected, EMC-Compliant, 23kbps Human Body Model Figure 2a shows the Human Body Model, and Figure 2b shows the current waveform it generates when discharged into a low impedance. This model consists of a 1pF capacitor charged to the ES voltage of interest, which is then discharged into the device through a 1.5kΩ resistor. IEC1-4-2 The IEC1-4-2 standard covers ES testing and performance of finished equipment; it does not specifically refer to integrated circuits. The helps you design equipment that meets Level 4 (the highest level) of IEC1-4-2, without additional ES-protection components. The main difference between tests done using the Human Body Model and IEC1-4-2 is higher peak current in IEC Because series resistance is lower in the IEC1-4-2 ES test model (Figure 1a), the ES withstand voltage measured to this standard is generally lower than measured using the Human Body Model. Figure 1b shows the current waveform for the ±8k IEC1-4-2 Level 4 ES Contact-ischarge test. The Air-Gap test involves approaching the device with a charge probe. The Contact-ischarge method connects the probe to the device before the probe is energized. Machine Model The Machine Model for ES testing uses a 2pF storage capacitor and zero-discharge resistance. It mimics the stress caused by handling during manufacturing and assembly. Of course, all pins (not just RS-232 inputs and outputs) require this protection during manufacturing. Therefore, the Machine Model is less relevant to the I/O ports than are the Human Body Model and IEC Applications Information Use proper layout to ensure other devices on your board are not damaged in an ES strike. Currents as high as 6A can instantaneously pass into the ground, so be sure to minimize the ground-lead return path to the power supply. A separate return path to the power supply is recommend. Trace widths should be greater than 4 mils. Bypass CC,, and SS with.1µf capacitors as close to the part as possible to ensure maximum ES protection. Tie any transmitter inputs to GN or CC. No external protection diodes are needed because the is not sensitive to power-supply sequencing. R C 1M R 15Ω CHARGE-CURRENT LIMIT RESISTOR ISCHARGE RESISTANCE I P 1% 9% Ir PEAK-TO-PEAK RINGING (NOT RAWN TO SCALE) HIGH- OLTAGE C SOURCE Cs 1pF STORAGE CAPACITOR EICE UNER TEST AMPERES 36.8% 1% t RL TIME t L CURRENT WAEFORM Figure 2a. Human Body ES Test Model Figure 2b. Human Body Model Current Waveform 6

7 ±15k ES-Protected, EMC-Compliant, 23kbps 3. RIER INPUT 1.5 T PHL OUT T PLH OH Chip Topography T1OUT R1IN T2OUT CC T1IN R1OUT T2IN t F t R2 R2IN R3IN R2OUT R3OUT.181" (4.597mm) OL t F1 t R1 T3OUT T3IN T4OUT T4IN SIGNAL GENERATOR R L C L T5OUT T5IN Figure 3. Slew-Rate Test Circuit and Timing iagram SS GN.94" (2.388mm) TRANSISTOR COUNT: 195 SUBSTRATE CONNECTE TO GN 7

8 ±15k ES-Protected, EMC-Compliant, 23kbps Package Information e B A1 A.11mm.4in. C L - 8 IM A A1 B C E e H L INCHES MILLIMETERS E H Wide SO SMALL-OUTLINE PACKAGE (.3 in.) IM PINS INCHES MILLIMETERS A E H C L α IM A A1 B C E e H L α INCHES SEE ARIATIONS.256 BSC MILLIMETERS BSC e B A1 A SSOP SHRINK SMALL-OUTLINE PACKAGE IM PINS INCHES MILLIMETERS A 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. 8 Maxim Integrated Products, 12 San Gabriel rive, Sunnyvale, CA 9486 (48) Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.