Datasheet

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November 2007 Rev 7 1/18

ST3237EB

± 15 kV ESD protected, 1 µA, 3 to 5.5 V, 250 kbps

RS-232 transceiver with stand-by

Features

■ ESD protection for RS-232 I/O pins

– ±15 kV human body model

– ±8 kV IEC 1000-4-2 contacts discharge

■ 1 µA low power shutdown with receivers active

■ Guaranteed data rate

– 250 kbps (normal operation)

– 1 Mbps (very high speed operation)

■ Guaranteed slew rate range

– 6 V/µs (normal operation)

– 24 V/µs (very high speed operation)

■ 0.1 µF external capacitors

■ Flow-through pinout

■ Low supply current 300 µA

■ Available in SSOP28 and SO-28

Description

The ST3237E is a 3 V to 5.5 V powered EIA/TIA-

232 and V.28/V.24 communication interfaces high

data-rate capability and enhanced electrostatic

discharge (ESD) protection at ±8 kV using

IEC1000-4-2 contact discharge and ±15 kV using

Human Body Model (HBM). The other pins are

protected with standard ESD protection at ±2 kV

using HBM method. The ST3237C is a

transceiver (5 drivers, 3 receivers) for fast modem

applications.

The device has a proprietary low-dropout

transmitter output stage providing true RS-232

performance from a 3 V to 5.5 V supply using a

dual charge pump. The device is guaranteed to

run at data rates of 250 kbps in the normal

operation mode and 1 Mbps in the very high

speed operation mode while maintaining RS-232

output levels.

SSOP

SOP

Table 1. Device summary

Order code

Temperature

range

Package Packaging

ST3237EBDR -40 to 85 °C SO-28 (tape and reel) 1000 parts per reel

ST3237EBPR -40 to 85°C SSOP28 (tape and reel) 1350 parts per reel

www.st.com

Summary of content (18 pages)

PAGE 1
ST3237EB ± 15 kV ESD protected, 1 µA, 3 to 5.5 V, 250 kbps RS-232 transceiver with stand-by Features ■ ESD protection for RS-232 I/O pins – ±15 kV human body model – ±8 kV IEC 1000-4-2 contacts discharge ■ 1 µA low power shutdown with receivers active ■ Guaranteed data rate – 250 kbps (normal operation) – 1 Mbps (very high speed operation) ■ Guaranteed slew rate range – 6 V/µs (normal operation) – 24 V/µs (very high speed operation) ■ 0.
PAGE 2
Contents ST3237EB Contents 1 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5 Typical performance characteristics . . . . .
PAGE 3
ST3237EB Pin configuration 1 Pin configuration Figure 1. Pin connection Table 2. Pin description Pin 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.
PAGE 4
Pin configuration Table 2. 4/18 ST3237EB Pin description (continued) Pin 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.
PAGE 5
ST3237EB Absolute maximum ratings 2 Absolute maximum ratings Table 3. 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-| Transmitter input voltage range TIN 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.
PAGE 6
Electrical characteristics ST3237EB 3 Electrical characteristics Table 5. Electrical characteristics (C1 - C4 = 0.1 µF, VCC = 3 V to 5.5 V, TA = -40 to 85 °C, unless otherwise specified. Typical values are referred to TA = 25 °C) Symbol ISUPPLY ISHDN Table 6. Parameter VTIH IIL VHYS Min. VCC power supply current SHDN=VCC, No Load Shutdown supply current SHDN=GND, VT_IN=GND or VCC Typ. Max. Unit 0.3 1 mA 1 5 µA Logic input (C1 - C4 = 0.1 µF, VCC = 3 V to 5.
PAGE 7
ST3237EB Table 8. Symbol Electrical characteristics Receiver (C1 - C4 = 0.1 µF tested at 3.3 V ±10 %, VCC = 3 V to 5.5 V, TA = -40 to 85 °C, unless otherwise specified.
PAGE 8
Application ST3237EB 4 Application Figure 3. Application circuits Table 10. Capacitance value (µF) 8/18 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.
PAGE 9
ST3237EB Typical performance characteristics 5 Typical performance characteristics Figure 4. (unless otherwise specified TJ = 25°C) Low level receiver output current Figure 5. Figure 6. ESD protection Note: The high ESD protected pins are the I/O RS232 line, transmitter out and receiver in. The other pins guarantee ± 2 kV HBM ESD protection versus ground by means of diodes.
PAGE 10
Application note 6 ST3237EB 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.
PAGE 11
ST3237EB Application note 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. Figure 9. IEC 1000-4-2 circuit Figure 10. IEC 1000-4-2 current waveform Table 11.
PAGE 12
Package mechanical data 7 ST3237EB Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK® packages. These packages have a lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK is an ST trademark.
PAGE 13
ST3237EB Package mechanical data 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.
PAGE 14
Package mechanical data ST3237EB SSOP28 mechanical data mm. inch. Dim. Min. Typ. A 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 14/18 Max. 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.
PAGE 15
ST3237EB Package mechanical data Tape & reel SO-28 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 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.
PAGE 16
Package mechanical data ST3237EB Tape & reel SSOP28 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 16/18 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.
PAGE 17
ST3237EB Revision history 8 Revision history Table 12. Document revision history Date Revision Changes 21-Mar-2005 5 TSSOP has been removed. 24-Mar-2006 6 Order codes updated. 13-Nov-2007 7 Added Table 1.
PAGE 18
ST3237EB 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.