ST3237E ± 15KV ESD-protected, 1µA, 3 to 5.5V, 250Kbps RS-232 Transceiver with stand-by Feature summary ■ ESD protection for RS-232 I/O pins – ±15KV human body model – ±8KV IEC 1000-4-2 contacts discharge ■ 1µA low power shutdown with receivers active ■ Guaranteed data rate – 250Kbps (normal operation) – 1Mbps (very high speed operation) ■ Guaranteed slew rate range – 6V/µs (normal operation) – 24V/µs (very high speed operation) ■ 0.1µF external capacitors ■ Flow-through pinout ■ Low supply current 300µA ■ Available in SSOP-28 and SO-28 SSOP SOP transceiver (5 drivers, 3 receivers) for fast modem applications. Description The device has a proprietary low-dropout transmitter output stage providing true RS-232 performance from a 3V to 5.5V supply using a dual charge pump. The device is guaranteed to run at data rates of 250Kbps in the normal operation mode and 1Mbps in the very high speed operation mode while maintaining RS-232 output levels.. The ST3237E is a 3V to 5.5V powered EIA/TIA232 and V.28/V.24 communication interfaces high data-rate capability and enhanced electrostatic discharge (ESD) protection at ±8KV using IEC1000-4-2 contact discharge and ±15kV using Human Body Model (HBM). The other pins are protected with standard ESD protection at ±2kV using HBM method. The ST3237C is a Order codes Part number Temperature range Package Comments ST3237EBDR -40 to 85 °C SO-28 (Tape & Reel) 1000 parts per reel ST3237ECPR 0 to 70 °C SSOP-28 (Tape & Reel) 1350 parts per reel ST3237EBPR -40 to 85°C SSOP-28 (Tape & Reel) 1350 parts per reel March 2006 Rev 6 1/17 www.st.com 17 Contents ST3237E Contents 1 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4 Application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6 Application note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2/17 ST3237E Pin configuration 1 Pin configuration Figure 1. Pin connection Table 1. Pin description PlN N° SYMBOL NAME AND FUNCTION 1 C2+ Positive Terminal of Inverting Charge Pump Capacitor 2 GND Ground 3 C2- Negative Terminal of Inverting Charge Pump Capacitor 4 V- 5.5V Generated by the Charge Pump 5 T1OUT First Transmitter Output Voltage 6 T2OUT Second Transmitter Output Voltage 7 T3OUT Third Transmitter Output Voltage 8 R1IN First Receiver Input Voltage 9 R2IN Second Receiver Input Voltage 10 T4OUT 11 R3IN 12 T5OUT 13 EN 14 SHDN Shutdown Control, Active Low 15 VHSCI Very High Speed Control Input. Connect to GND for normal operation; connect to VCC for 1Mbps transmission rates. 16 R1OUTB Non Inverting Complementary Receiver Output. Always Active. 17 T5IN Fifth Transmitter Input Voltage 18 R3OUT Third Receiver Output Voltage Fourth Transmitter Output Voltage Third Receiver Input Voltage Fifth Transmitter Output Voltage Receiver Enable, Active Low 3/17 Pin configuration Table 1. 4/17 ST3237E Pin description PlN N° SYMBOL NAME AND FUNCTION 19 T4IN Fourth Transmitter Input Voltage 20 R2OUT Second Receiver Output Voltage 21 R1OUT First Receiver Output Voltage 22 T3IN Third Transmitter Input Voltage 23 T2IN Second Transmitter Input Voltage 24 T1N First Transmitter Input Voltage 25 C1- Negative Terminal of Voltage- Charge Pump Capacitor 26 VCC Supply Voltage 27 V+ -5.5V Generated by the Charge Pump 28 C1+ Positive Terminal of Voltage- Charge Pump Capacitor ST3237E Absolute maximum ratings 2 Absolute maximum ratings Table 2. Absolute maximum ratings Symbol Parameter Value Unit VCC Supply voltage -0.3 to 6 V V+ Doubled voltage terminal -0.3 to 7 V V- Inverted voltage terminal 0.3 to -7 V 13 V -0.3 to 6 V -0.3 to 6 V V+ +|V-| TIN Transmitter input voltage range SHDN, EN VHSCI Very high speed control input -0.3 to (VCC +0.3) V RIN Receiver input voltage range ± 25 V ± 13.2 V -0.3 to (VCC + 0.3) V TOUT Transmitter output voltage range ROUT, ROUTB Receiver output voltage range tSHORT Short circuit duration on TOUT (one at a time) Continuous Storage temperature range -65 to 150 Tstg °C Note: Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. V+ and V- can have a maximum magnitude of +7V, but their absolute addition can not exceed 13 V. Table 3. Shutdown and enable control truth table SHDN EN T-OUT R-OUT R-OUTB 0 0 High Z Active Active 0 1 High Z High Z Active 1 0 Active Active Active 1 1 Active High Z Active Figure 2. Symbol ESD performance: transmitter outputs, receiver inputs Parameter Test conditions Min. Typ. Max. Unit ESD ESD protection voltage Human body model ±15 kV ESD ESD protection voltage IEC-1000-4-2 contact discharge ±8 kV 5/17 Electrical characteristics ST3237E 3 Electrical characteristics Table 4. Electrical characteristics (C1 - C4 = 0.1µF, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to TA = 25°C) Symbol Parameter ISUPPLY VCC Power Supply Current ISHDN Table 5. Symbol Test conditions SHDN=VCC, No Load Shutdown Supply Current SHDN=GND, V T_IN=GND or VCC Typ. Max. Unit 0.3 1 mA 1 5 µA Logic input (C 1 - C4 = 0.1µF, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to TA = 25°C) Parameter Test conditions VTIL Input Logic Threshold Low (Note 1) T-IN, VHSCI, EN, SHDN VTIH Input Logic Threshold High T-IN, VHSCI, EN, SHDN IIL Input Leakage Current T-IN, VHSCI, EN, SHDN VHYS Min. VCC = 3.3V VCC = 5V Min. Typ. Max. Unit 0.8 V 2 V 2.4 ± 1.0 Transmitter Input Hysteresis µA 0.25 V Note: Transmitter input hysteresis is typically 250mV Table 6. Transmitter (C1 - C4 = 0.1µF tested at 3.3V±10%, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to TA = 25°C) Symbol Parameter Test conditions Min. Typ. Max. Unit VTOUT Output voltage swing All transmitter outputs are loaded with 3KΩ to GND ±5 ± 5.4 V RTOUT Transmitter output resistance VCC = 0V, VOUT = ± 2V 300 10M W ± 60 mA 6/17 ISC Output short circuit current ITOL Output leakage current VCC = 0V or 3.3V to 5.5V VOUT = ± 12V Transmitters disable ± 25 µA ST3237E Table 7. Symbol Electrical characteristics Receiver (C1 - C4 = 0.1µF tested at 3.3V±10%, VCC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to TA = 25°C) Parameter Test conditions IOL Output leakage current Receiver disabled, EN = VCC VOL Output voltage low IOUT = 1mA VOH Output voltage high IOUT = -1mA VRIN Receiver input voltage operating range VRIL RS-232 input threshold low VRIH RS-232 input threshold high VRIHYS Input hysteresis RRIN Input resistance Table 8. Symbol DR Min. VCC-0.6 Typ. Max. Unit ± 0.05 ± 10 µA 0.4 V VCC-0.1 -25 V 25 TA = 25°C, VCC = 3.3V 0.6 1.1 TA = 25°C, VCC = 5V 0.8 1.5 V V TA = 25°C, VCC = 3.3V 1.5 2.4 TA = 25°C, VCC = 5V 1.2 2.4 V 0.3 TA = 25°C 3 V 5 7 KΩ Timing characteristics (C1 - C 4 = 0.1µF tested at 3.3V±10%, V CC = 3V to 5.5V, TA = -40 to 85°C, unless otherwise specified. Typical values are referred to TA = 25°C) Parameter Maximum data rate Test conditions Min. Typ. 250 Kbps RL = 3KΩ, C L= 250pF one transmitter switching, VHSCI=VCC VCC= 3 to 4.5V 1000 Kbps RL = 3KΩ, C L= 1000pF one transmitter switching, VHSCI=VCC VCC= 4.5 to 5.5V 1000 Kbps Propagation delay input to output RIN to ROUT, CL = 150pF 0.15 tPHLR tPLHR Propagation delay input to output RL = 3kΩ, CL = 1000pF, VHSCI=VCC VHSCI=GND 400 1000 tR_SKEW Receiver skew Unit RL = 3KΩ, C L= 1000pF one transmitter switching, VHSCI=GND tPHLR tPLHR tT_SKEW Transmitter skew Max. µs ns ns |tPHL - tTLH|, VHSCI=GND 300 ns |tPHL - tTLH|, VHSCI=VCC 50 ns |tPHL - tTLH| 100 ns tOER Receiver output enable time Normal operation 50 ns tODR Receiver output disable time Normal operation 120 ns SRT Note: Transition slew rate TA = 25°C RL = 3 to 7KΩ, VCC = 3.3V measured from +3V to -3V or -3V to +3V CL = 150pF to 1000pF, VHSCI=GND CL = 150pF to 1000pF, VHSCI=VCC CL = 150pF to 2500pF, VHSCI=GND 6 24 4 30 150 30 V/µs V/µs V/µs Transmitter Skew is measured at the transmitter zero cross points 7/17 Application circuits 4 8/17 ST3237E Application circuits Figure 3. Application circuits Table 9. Capacitance value (µF) VCC C1 C2 C3 C4 Cbypass 3.0 to 3.6 0.22 0.22 0.22 0.22 0.1 3.1 to 3.6 0.1 0.1 0.1 0.1 0.1 4.5 to 5.5 0.047 0.33 0.33 0.33 0.1 3.0 to 5.5 0.22 0.1 0.1 0.1 0.1 ST3237E 5 Typical performance characteristics Typical performance characteristics (unless otherwise specified TJ = 25°C) Note: Figure 4. Low level receiver output current Figure 6. ESD Protection Figure 5. High level receiver output current The High ESD protected pins are the I/O RS232 line, transmitter out and receiver in. The other pins guarantee ± 2KV HBM ESD protection versus ground by means of diodes. 9/17 Application note 6 ST3237E Application note This application note describes the procedure for determining the susceptibility and the test method to verify ST ESD advanced protection on RS-232 or RS485 I/O device. Static electricity is defined as an electrical charge caused by an imbalance of electrons on the surface of a material. This imbalance of electrons produces an electric field that can be measured and that can influence other objects at a distance. Electrostatic discharge is defined as the transfer of charge between bodies at different electrical potentials. Electrostatic discharge (ESD) can change the electrical characteristics of a semiconductor device, degrading or destroying it. Any input or output port (I/O) allows access communication with other pieces of equipment by external connectors. These connectors are directly linked by the I/O pins of RS-232 or RS485 interface. ST provides the E-series by advanced high ESD protection structure. The protection functionality is tested in two different conditions: The first model is used to simulate the HUMAN BODY MODEL (HBM) event. A similar discharge can occur from a charged conductive object, such as a metallic tool or fixture. The model used to characterize this event is known as the Machine Model. A Human Body Model circuit and waveform is presented in Figures below. Figure 7. Human body model circuit Figure 8. Human body model current waveform The second model is IEC 1000-4-2 and is used to simulate the reaction of the device on equipment when subjected to electrostatic discharges, which may occur from personnel to objects near vital instrumentation. Direct (Contact) and indirect (Air Gap) applications of discharges to the equipment under test (EUT) are possible. Test characteristics are shown in circuit, waveform and table below. 10/17 ST3237E Application note Figure 9. IEC 1000-4-2 circuit Figure 10. IEC 1000-4-2 current waveform Table 10. Characteristics of the ESD generator Level Indicated voltage First peak current of discharge (± 10%) Rise time with discharge switch Current at 30 ns (± 30%) Current at 60 ns (± 30%) 1 2 KV 7.5 A 0.7 to 1ns 4A 2A 2 4 KV 15 A 0.7 to 1ns 8A 4A 3 6 KV 22.5 A 0.7 to 1ns 12 A 6A 4 8 KV 30 A 0.7 to 1ns 16 A 8A 11/17 Application note ST3237E SO-28 MECHANICAL DATA mm. inch DIM. MIN. TYP A MAX. MIN. TYP. 2.65 MAX. 0.104 a1 0.1 0.3 0.004 0.012 b 0.35 0.49 0.014 0.019 b1 0.23 0.32 0.009 0.012 C 0.5 0.020 c1 45˚ (typ.) D 17.70 18.10 0.697 0.713 E 10.00 10.65 0.393 0.419 e 1.27 0.050 e3 16.51 0.650 F 7.40 7.60 0.291 0.300 L 0.50 1.27 0.020 0.050 S 8 ˚ (max.) 0016023 12/17 ST3237E Application note SSOP28 MECHANICAL DATA mm. inch DIM. MIN. TYP A MAX. MIN. TYP. 2 A1 0.050 A2 1.65 b MAX. 0.079 0.002 1.85 0.065 0.22 0.38 0.009 0.015 c 0.09 0.25 0.004 0.010 D 9.9 10.2 10.5 0.390 0.402 0.413 E 7.4 7.8 8.2 0.291 0.307 0.323 E1 5 5.3 5.6 0.197 0.209 0.220 e 1.75 0.65 BSC K 0˚ L 0.55 0.75 0.069 0.073 0.0256 BSC 10˚ 0˚ 0.95 0.022 10˚ 0.030 0.037 13/17 Application note ST3237E Tape & Reel SO-28 MECHANICAL DATA mm. inch DIM. MIN. A MAX. MIN. 330 13.2 TYP. MAX. 12.992 C 12.8 D 20.2 0.795 N 60 2.362 T 14/17 TYP 0.504 30.4 0.519 1.197 Ao 10.8 11.0 0.425 0.433 Bo 18.2 18.4 0.716 0.724 Ko 2.9 3.1 0.114 0.122 Po 3.9 4.1 0.153 0.161 P 11.9 12.1 0.468 0.476 ST3237E Application note Tape & Reel SSOP28 MECHANICAL DATA mm. inch DIM. MIN. A TYP MAX. MIN. 330 MAX. 12.992 C 12.8 D 20.2 0.795 N 60 2.362 T 13.2 TYP. 0.504 22.4 0.519 0.882 Ao 8.4 8.6 0.331 0.339 Bo 10.7 10.9 0.421 0.429 Ko 2.9 3.1 0.114 0.122 Po 3.9 4.1 0.153 0.161 P 11.9 12.1 0.468 0.476 15/17 Revision history ST3237E 7 Revision history Table 11. Revision history Date Revision 21-Mar-2005 5 TSSOP has been removed. 24-Mar-2006 6 Order codes has been updated and new template. 16/17 Changes ST3237E Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no liability whatsoever relating to the choice, selection or use of the ST products and services described herein. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. 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