ISL3332, ISL3333 ¬ Data Sheet May 27, 2008 3.3V, ±15kV ESD Protected, Two Port, Dual Protocol (RS-232/RS-485) Transceivers The ISL3332, ISL3333 are two port interface ICs where each port can be independently configured as a single RS-485/422 transceiver, or as a dual (2 Tx, 2 Rx) RS-232 transceiver. With both ports set to the same mode, two RS-485/RS-422 transceivers, or four RS-232 transceivers are available. If either port is in RS-232 mode, the onboard charge pump generates RS-232 compliant ±5V Tx output levels from a single VCC supply as low as 3.15V. The transceivers are RS-232 compliant, with the Rx inputs handling up to ±25V. In RS-485 mode, the transceivers support both the RS-485 and RS-422 differential communication standards. The receivers feature "full failsafe" operation, so the Rx outputs remain in a high state if the inputs are open or shorted together. The transmitters support up to three data rates, two of which are slew rate limited for problem free communications. The charge pump disables when both ports are in RS-485 mode, thereby saving power, minimizing noise, and eliminating the charge pump capacitors. FN6362.0 Features • ±15kV (HBM) ESD Protected Bus Pins (RS-232 or RS-485) • Operates From a Single 3.3V Supply • Two Independent Ports, Each User Selectable for RS-232 (2 Transceivers) or RS-485/RS-422 (1 Transceiver) • True Flow-Through Pinouts Simplify Board Layouts • Pb-free (RoHS compliant) • Full Failsafe (Open/Short) Rx in RS-485/422 Mode • Loopback Mode Facilitates Board Self Test Functions • User Selectable RS-485 Data Rates (ISL3333 Only) - Fast Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Mbps - Slew Rate Limited. . . . . . . . . . . . . . . . . . . . . . . 460kbps - Slew Rate Limited. . . . . . . . . . . . . . . . . . . . . . . 115kbps • Fast RS-232 Data Rate . . . . . . . . . . . . . . . Up to 400kbps • RS-232 Tx and Rx Enable Pins (ISL3333 Only) • Small Charge Pump Caps . . . . . . . . . . . . . . . . . 4 x 0.1µF • Low Current Shutdown Mode. . . . . . . . . . . . . . . . . . .35µA Both RS-232 and RS-485 modes feature loopback and shutdown functions. Loopback internally connects the Tx outputs to the corresponding Rx input, to facilitate board level self test implementation. The outputs remain connected to the loads during loopback, so connection problems (e.g., shorted connectors or cables) can be detected. Shutdown mode disables the Tx and Rx outputs, disables the charge pumps, and places the IC in a low current (35µA) mode. • QFN Package Saves Board Space (ISL3333 Only) The ISL3333 is a QFN packaged device that includes two additional user selectable, lower speed and edge rate options for EMI sensitive designs, or to allow longer bus lengths. It also features a logic supply pin (VL) that sets the VOH level of logic outputs, and the switching points of logic inputs, to be compatible with another supply voltage in mixed voltage systems. The QFN also adds RS-232 mode Tx EN pins (DEN), and active low Rx enable pins (RXEN) to increase design flexibility. In RS-485 applications, active low Rx enable pins allow Tx/Rx direction control, via a single signal per port, by connecting the corresponding DE and RXEN pins together. • Factory Automation • Logic Supply Pin (VL) Eases Operation in Mixed Supply Systems (ISL3333 Only) Applications • Gaming Applications (e.g., Slot Machines) • Single Board Computers • Security Networks • Industrial/Process Control Networks • Level Translators (e.g., RS-232 to RS-422) • Point of Sale Equipment • Dual Channel RS-485 Interfaces For a single port version of these devices, please see the ISL3330, ISL3331 data sheet. TABLE 1. SUMMARY OF FEATURES NO. OF PART NUMBER PORTS PACKAGE OPTIONS RS-485 DATA RATE (bps) ISL3332 2 28 Ld SSOP ISL3333 2 40 Ld QFN (6 x 6mm) 20M, 460k, 115k 1 20M RS-232 DATA RATE (kbps) VL PIN? RS-232 Tx ENABLE? ACTIVE H or L LOW POWER Rx ENABLE? SHUTDOWN? 400 NO NO NONE YES 400 YES YES L YES CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2008. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. ISL3332, ISL3333 Ordering Information PART NUMBER (NOTE) PART MARKING TEMP. RANGE (°C) PACKAGE (Pb-Free) PKG. DWG. # ISL3332IAZ* 3332 IAZ -40 to +85 28 Ld SSOP M28.209 ISL3333IRZ* 3333 IRZ -40 to +85 40 Ld QFN L40.6x6 *Add “-T” suffix for tape and reel. Please refer to TB347 for details on reel specifications. NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. Pinouts Z1 7 VL 23 DZ1/DE1 NC Y1 6 NC 24 RA1 VCC 25 RB1 B1 5 C2- A1 4 C2+ 26 VCC C1+ 27 C2- V+ 3 C1- 28 C2+ C1- 2 NC C1+ 1 ISL3333 (40 LD QFN) TOP VIEW NC ISL3332 (28 LD SSOP) TOP VIEW 40 39 38 37 36 35 34 33 32 31 V+ 1 30 RB1 A1 2 29 RA1 22 DY1 B1 3 28 DZ1/DE1 SEL1 8 21 LB Y1 4 27 DY1 SEL2 9 20 ON/OFF Z1 5 26 LB Z2 10 19 DY2 23 DZ2/DE2 Y2 9 22 RA2 B2 10 21 RB2 2 11 12 13 14 15 16 17 18 19 20 DEN2 8 V- Z2 15 V- GND 14 RXEN2 24 DY2 RXEN1 7 16 RB2 GND SEL2 A2 13 GND 25 ON/OFF SPB 6 SPA SEL1 17 RA2 DEN1 18 DZ2/DE2 A2 Y2 11 B2 12 FN6362.0 May 27, 2008 ISL3332, ISL3333 TABLE 2. ISL3332 FUNCTION TABLE INPUTS RECEIVER OUTPUTS DRIVER OUTPUTS SEL1 or 2 ON/OFF DE 1 or 2 RA RB Y Z CHARGE PUMPS (NOTE 1) MODE 0 1 N.A. ON ON ON ON ON RS-232 X 0 X High-Z High-Z High-Z High-Z OFF Shutdown 1 1 0 ON High-Z * High-Z High-Z OFF RS-485 1 1 1 ON High-Z * ON ON OFF RS-485 NOTE: 1. Charge pumps are off if SEL1 = SEL2 = 1, or if ON/OFF = 0. If ON = 1, and either port is programmed for RS-232 mode, then the charge pumps are on. ISL3332 Truth Tables (FOR EACH PORT) RS-232 TRANSMITTING MODE INPUTS SEL1 or 2 ON/OFF RS-485 TRANSMITTING MODE OUTPUTS DY DZ Y Z INPUTS SEL1 or 2 ON/OFF OUTPUTS DE1 or 2 DY Y Z 0 1 0 0 1 1 1 1 1 0 1 0 0 1 0 1 1 0 1 1 1 1 0 1 0 1 1 0 0 1 1 1 0 X High-Z High-Z 0 1 1 1 0 0 1 0 X X High-Z High-Z 0 0 X X High-Z High-Z RS-485 RECEIVING MODE RS-232 RECEIVING MODE INPUTS SEL1 or 2 ON/OFF INPUTS OUTPUT A B RA RB SEL1 or 2 ON/OFF OUTPUT B-A RA RB * 0 1 0 0 1 1 1 1 ≥ -40mV 1 High-Z 0 1 0 1 1 0 1 1 ≤ -200mV 0 High-Z 0 1 1 0 0 1 1 1 Open or Shorted together 1 High-Z 0 1 1 1 0 0 1 0 X High-Z High-Z 0 1 Open Open 1 1 0 0 X X High-Z High-Z 3 * Internally pulled high through a 40kΩ resistor. FN6362.0 May 27, 2008 ISL3332, ISL3333 TABLE 3. ISL3333 FUNCTION TABLE INPUTS SEL1 or 2 ON/OFF SPA SPB RXEN 1 or 2 DEN 1 or 2 DE 1 or 2 RECEIVER OUTPUTS DRIVER OUTPUTS RA RB Y Z DRIVER CHARGE DATA RATE PUMPS (NOTE 2) (Mbps) MODE 0 1 X X 0 0 N.A. ON ON High-Z High-Z ON 0.46 RS-232 0 1 X X 0 1 N.A. ON ON ON ON ON 0.46 RS-232 0 1 X X 1 0 N.A. High-Z High-Z High-Z High-Z ON 0.46 RS-232 0 1 X X 1 1 N.A. High-Z High-Z ON ON ON 0.46 RS-232 High-Z X 0 X X X X X High-Z High-Z High-Z OFF N.A. Shutdown 1 1 X X 0 N.A. 0 ON High-Z * High-Z High-Z OFF N.A. RS-485 1 1 0 0 0 N.A. 1 ON High-Z * ON ON OFF 0.46 RS-485 1 1 0 1 0 N.A. 1 ON High-Z * ON ON OFF 0.115 RS-485 1 1 1 0 0 N.A. 1 ON High-Z * ON ON OFF 20 RS-485 1 1 1 1 0 N.A. 1 ON High-Z * ON 1 1 X X 1 N.A. 0 High-Z High-Z * High-Z 1 1 0 0 1 N.A. 1 High-Z High-Z * 1 1 0 1 1 N.A. 1 1 1 1 0 1 N.A. 1 1 1 1 1 1 N.A. 1 ON OFF 20 RS-485 High-Z OFF N.A. RS-485 ON ON OFF 0.46 RS-485 High-Z High-Z * ON ON OFF 0.115 RS-485 High-Z High-Z * ON ON OFF 20 RS-485 High-Z High-Z * ON ON OFF 20 RS-485 NOTE: 2. Charge pumps are off if SEL1 = SEL2 = 1, or if ON/OFF = 0. If ON = 1, and either port is programmed for RS-232 mode, then the charge pumps are on. ISL3333 Truth Tables (FOR EACH PORT) RS-485 TRANSMITTING MODE RS-232 TRANSMITTING MODE INPUTS OUTPUTS SEL1 or 2 ON/OFF DEN1 or 2 DY DZ Y Z 0 1 1 0 0 1 1 0 1 1 0 1 1 0 0 1 1 1 0 0 1 0 1 1 1 1 0 0 0 1 0 X X High-Z High-Z 0 0 X X X High-Z High-Z SEL1 ON/ DE or 2 OFF 1 or 2 SPA SPB DY Y Z Mbps 1 1 0 0 0/1 1/0 0/1 0.46 1 1 1 0 1 0/1 1/0 0/1 0.115 1 1 1 1 X 0/1 1/0 0/1 20 1 1 0 X X X High-Z High-Z N.A. 1 0 X X X X High-Z High-Z N.A. RS-485 RECEIVING MODE INPUTS OUTPUT RXEN 1 or 2 SEL1 or 2 ON/OFF DATA RATE 1 RS-232 RECEIVING MODE INPUTS OUTPUTS INPUTS A B RA RB OUTPUT SEL1 or 2 ON/OFF RXEN 1 or 2 B-A RA RB * 1 1 0 ≥ -40mV 1 High-Z 0 1 0 0 0 1 1 0 1 0 0 1 1 0 1 1 0 ≤ -200mV 0 High-Z 0 1 0 1 0 0 1 1 1 0 1 High-Z 0 1 0 1 1 0 0 Open or Shorted together 0 1 0 Open Open 1 1 1 1 1 X High-Z High-Z 0 1 1 X X High-Z High-Z 1 0 X X High-Z High-Z 0 0 X X X High-Z High-Z 4 * Internally pulled high through a 40kΩ resistor. FN6362.0 May 27, 2008 ISL3332, ISL3333 Pin Descriptions PIN MODE FUNCTION GND BOTH Ground connection. LB BOTH Enables loopback mode when low. Internally pulled-high. NC BOTH No Connection. ON/OFF BOTH If either port is in RS-232 mode, a low on ON/OFF disables the charge pumps. In either mode, a low disables all the outputs, and places the device in low power shutdown. Internally pulled-high. ON = 1 for normal operation. RXEN BOTH Active low receiver output enable. The corresponding port’s Rx is enabled when RXEN is low; Rx is high impedance when RXEN is high. Internally pulled low. (QFN only) SEL BOTH Interface Mode Select input. High puts corresponding port in RS-485 Mode, while a low puts it in RS-232 Mode. VCC BOTH System power supply input (3.3V). VL BOTH Logic-Level Supply. All TTL/CMOS inputs and outputs are powered by this supply. QFN logic input pins that are externally tied high in an application, should use the VL supply for the high voltage level. (QFN only) DEN A RS-232 Active high driver output enable. The corresponding port’s 232 mode drivers are enabled when DEN is high; drivers are disabled when DEN is low. Internally pulled high. (QFN only). RS-232 Receiver input with ±15kV ESD protection. A low on A forces RA high; A high on A forces RA low. RS-485 Inverting receiver input with ±15kV ESD protection. B RS-232 Receiver input with ±15kV ESD protection. A low on B forces RB high; A high on B forces RB low. RS-485 Noninverting receiver input with ±15kV ESD protection. DY RS-232 Driver input. A low on DY forces output Y high. Similarly, a high on DY forces output Y low. RS-485 Driver input. A low on DY forces output Y high and output Z low. Similarly, a high on DY forces output Y low and output Z high. DZ / DE RS-232 Driver input. A low on DZ forces output Z high. Similarly, a high on DZ forces output Z low. RS-485 Driver output enable (DE). The driver outputs, Y and Z, are enabled by bringing DE high. They are high impedance when DE is low. Internally pulled high when port selected for RS-485 mode. RA RS-232 Receiver output. RS-485 Receiver output: If B > A by at least -40mV, RA is high; If B < A by -200mV or more, RA is low; RA = High if A and B are unconnected (floating) or shorted together (i.e., full fail-safe). RB RS-232 Receiver output. RS-485 Not used. Internally pulled-high, and unaffected by RXEN. Y RS-232 Driver output with ±15kV ESD protection. RS-485 Inverting driver output with ±15kV ESD protection. Z RS-232 Driver output with ±15kV ESD protection. RS-485 Noninverting driver output with ±15kV ESD protection. SP RS-485 Speed control. Internally pulled-high. (QFN only) C1+ RS-232 External capacitor (voltage doubler) is connected to this lead. Not needed if both ports in RS-485 Mode. C1- RS-232 External capacitor (voltage doubler) is connected to this lead. Not needed if both ports in RS-485 Mode. C2+ RS-232 External capacitor (voltage inverter) is connected to this lead. Not needed if both ports in RS-485 Mode. C2- RS-232 External capacitor (voltage inverter) is connected to this lead. Not needed if both ports in RS-485 Mode. V+ RS-232 Internally generated positive RS-232 transmitter supply (+5.5V). C3 not needed if both ports in RS-485 Mode. V- RS-232 Internally generated negative RS-232 transmitter supply (-5.5V). C4 not needed if both ports in RS-485 Mode. 5 FN6362.0 May 27, 2008 ISL3332, ISL3333 Typical Operating Circuits RS-232 MODE WITHOUT LOOPBACK +3.3V C1 0.1µF C2 0.1µF + +3.3V 0.1μF 1 + 2 28 + 27 C1+ VCC V+ 3 C1C2+ V- 15 C2- 24 R 5kΩ 5 B1 + 0.1µF 26 4 A1 RS-232 MODE WITH LOOPBACK + C3 0.1µF C4 0.1µF + RA1 25 RB1 R 5kΩ 1 C1 0.1µF + 2 28 C2 0.1µF + 27 26 C1+ V- 15 5 7 Z1 22 D 23 D DEN1 VCC (QFN ONLY) 8 LB ON/OFF SEL1 DY1 DZ1 21 VCC 20 6 Y1 VCC VCC SEL1 1 C2 0.1µF + A1 B1 2 28 27 VCC RS-485 MODE WITH LOOPBACK + 3 V- 15 C2- 4 24 R + C3 0.1µF C4 0.1µF + C1 0.1µF C2 0.1µF A1 RA1 B1 0.1µF 1 + 2 28 + 27 C1+ Z1 VCC V+ 3 V- 15 C2- 4 24 R 5 + C3 0.1µF C4 0.1µF + RA1 RXEN1 25 6 22 D 7 LB Rx RB1 25 DY1 Y1 Z1 23 DE1 LB 8 ON/OFF SEL1 GND 14 NOTE: PINOUT FOR SSOP SAME FOR PORT 2. 6 VCC 20 6 22 VCC D 7 23 21 VCC VCC 26 C1C2+ (QFN ONLY) Y1 VCC NOTE: PINOUT FOR SSOP SAME FOR PORT 2. V+ C1C2+ 5 20 ON/OFF 14 26 C1+ GND GND +3.3V + DZ1 21 LB (QFN ONLY) 8 DY1 23 D DEN1 RS-485 MODE WITHOUT LOOPBACK C1 0.1µF 22 D 7 Z1 NOTE: PINOUT FOR SSOP SAME FOR PORT 2. 0.1µF RB1 LB Rx 14 + 25 R GND +3.3V RA1 5kΩ RXEN1 6 C4 0.1µF + 24 R 5kΩ B1 + C3 0.1µF C2- (QFN ONLY) Y1 3 V+ C1C2+ 4 A1 VCC DE1 21 VCC VCC LB 8 RB1 DY1 ON/OFF SEL1 GND 20 VCC GND 14 NOTE: PINOUT FOR SSOP SAME FOR PORT 2. FN6362.0 May 27, 2008 ISL3332, ISL3333 Absolute Maximum Ratings (TA = +25°C) Thermal Information VCC to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V VL (QFN Only) . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to VCC + 0.5V Input Voltages All Except A,B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.5V to 7V Input/Output Voltages A, B (Any Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . -25V to +25V Y, Z (Any Mode, Note 3) . . . . . . . . . . . . . . . . . . . -12.5V to +12.5V RA, RB (non-QFN Package). . . . . . . . . . . . -0.5V to (VCC + 0.5V) RA, RB (QFN Package) . . . . . . . . . . . . . . . . -0.5V to (VL + 0.5V) Output Short Circuit Duration Y, Z, RA, RB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Indefinite ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table Thermal Resistance (Typical) θJA (°C/W) θJC (°C/W) 28 Ld SSOP Package (Note 5) . . . . . . 60 N/A 40 Ld QFN Package (Notes 4, 6). . . . . 31 2.5 Maximum Junction Temperature (Plastic Package) . . . . . . . +150°C Maximum Storage Temperature Range . . . . . . . . . .-65°C to +150°C Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp Operating Conditions Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +85°C CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. NOTES: 3. One output at a time, IOUT ≤ 100mA for ≤ 10 mins. 4. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech Brief TB379. 5. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details. 6. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside. Electrical Specifications Test Conditions: VCC = 3.15V to 3.45V, C1 - C4 = 0.1µF, VL = VCC (for QFN only); Unless Otherwise Specified. Typicals are at VCC = 3.3V, TA =+25°C (Note 7) PARAMETER SYMBOL TEST CONDITIONS TEMP MIN (°C) (Note 11) TYP MAX (Note 11) UNITS DC CHARACTERISTICS - RS-485 DRIVER (SEL = VCC) Driver Differential VOUT (no load) VOD1 Driver Differential VOUT (with load) VOD2 Change in Magnitude of Driver Differential VOUT for Complementary Output States Driver Common-Mode VOUT Change in Magnitude of Driver Common-Mode VOUT for Complementary Output States Full - - VCC V R = 50Ω (RS-422) (Figure 1) Full 2 2.3 - V R = 27Ω (RS-485) (Figure 1) Full 1.5 2 5 V VOD3 RD = 60Ω, R = 375Ω, VCM = -7V to 12V (Figure 1) Full 1.5 - 5 V ΔVOD R = 27Ω or 50Ω (Figure 1) Full - 0.01 0.2 V VOC R = 27Ω or 50Ω (Figure 1) Full - - 3.0 V ΔVOC R = 27Ω or 50Ω (Figure 1) Full - 0.01 0.2 V Full 35 - 250 mA Driver Short-Circuit Current, VOUT = High or Low IOS -7V ≤ (VY or VZ) ≤ 12V (Note 8) Driver Three-State Output Leakage Current (Y, Z) IOZ Outputs Disabled, VCC = 0V or 3.6V VOUT = 12V Full - - 200 µA VOUT = -7V Full -200 - - µA DC CHARACTERISTICS - RS-232 DRIVER (SEL = GND) Driver Output Voltage Swing VO All TOUTS Loaded with 3kΩ to Ground Full ±5.0 - - V Driver Output Short-Circuit Current IOS VOUT = 0V Full -60 - 60 mA DC CHARACTERISTICS - LOGIC PINS (i.e., DRIVER AND CONTROL INPUT PINS) Input High Voltage 7 VIH1 VL = VCC if QFN Full 2.2 - - V VIH2 2.7V ≤ VL < 3.0V (QFN Only) Full 2 - - V VIH3 2.3V ≤ VL < 2.7V (QFN Only) Full 1.6 - - V VIH4 1.6V ≤ VL < 2.3V (QFN Only) Full 0.7*VL - - V VIH5 1.2V ≤ VL < 1.6V (QFN Only) 25 - 0.7*VL - V FN6362.0 May 27, 2008 ISL3332, ISL3333 Electrical Specifications Test Conditions: VCC = 3.15V to 3.45V, C1 - C4 = 0.1µF, VL = VCC (for QFN only); Unless Otherwise Specified. Typicals are at VCC = 3.3V, TA =+25°C (Note 7) (Continued) PARAMETER SYMBOL Input Low Voltage Input Current TEST CONDITIONS TEMP MIN (°C) (Note 11) TYP MAX (Note 11) UNITS VIL1 VL = VCC if QFN Full - - 0.8 V VIL2 VL ≥ 2.7V (QFN Only) Full - - 0.8 V VIL3 2.3V ≤ VL < 2.7V (QFN Only) Full - - 0.7 V VIL4 1.6V ≤ VL < 2.3V (QFN Only) Full - - 0.35*VL V VIL5 1.3V ≤ VL < 1.6V (QFN Only) 25 - 0.35*VL - V VIL6 1.2V ≤ VL < 1.3V (QFN Only) 25 - 0.25*VL - V IIN1 Pins Without Pull-ups or Pull-downs Full -2 - 2 µA IIN2 LB, ON/OFF, DE (SP, RXEN, DEN, if QFN) Full -25 - 25 µA Full -0.2 - -0.04 V DC CHARACTERISTICS - RS-485 RECEIVER INPUTS (SEL = VCC) Receiver Differential Threshold Voltage VTH ΔVTH Receiver Input Hysteresis -7V ≤ VCM ≤ 12V, Full Failsafe VCM = 0V Receiver Input Current (A, B) IIN VCC = 0V or 3.0 to 3.6V Receiver Input Resistance RIN -7V ≤ VCM ≤ 12V, VCC = 0 (Note 9) or 3.0V ≤ VCC ≤ 3.6V VIN = 12V VIN = -7V 25 - 35 - mV Full - - 0.8 mA Full -0.64 - - mA Full 15 - - kΩ VIN Full -25 - 25 V DC CHARACTERISTICS - RS-232 RECEIVER INPUTS (SEL = GND) Receiver Input Voltage Range Receiver Input Threshold VIL Full - 1.1 0.8 V VIH Full 2.4 1.6 - V Receiver Input Hysteresis ΔVTH 25 - 0.5 - V Receiver Input Resistance RIN Full 3 5 7 kΩ Full VCC-0.4 - - V VIN = ±15V, VCC Powered Up (Note 9) DC CHARACTERISTICS - RECEIVER OUTPUTS (485 OR 232 MODE) Receiver Output High Voltage VOH1 IO = -1.5mA (VL = VCC if QFN) VOH2 IO = -100µA, VL ≥ 1.2V (QFN Only) Full VL-0.1 - - V VOH3 IO = -500µA, VL = 1.5V (QFN Only) Full 1.2 - - V VOH4 IO = -150µA, VL = 1.2V (QFN Only) Full 1.0 - - V Receiver Output Low Voltage VOL IO = 5mA Full - 0.2 0.4 V Receiver Short-Circuit Current IOSR 0V ≤ VO ≤ VCC Full 7 - 85 mA Receiver Three-State Output Current IOZR Output Disabled, 0V ≤ VO ≤ VCC (or VL for QFN) Full - - ±10 µA Unused Receiver (RB) Pull-Up Resistance ROBZ ON/OFF = VCC, SELX = VCC (RS-485 Mode) 25 - 40 - kΩ ICC232 SEL1 or SEL2 = GND, LB = ON/OFF = VCC Full - 3.7 7 mA ICC485 SEL 1 & 2 = LB = DE = ON/OFF = VCC Full - 1.6 5 mA Full - 45 100 µA SSOP Full - 35 80 µA QFN Full - 60 160 µA ±15 - kV POWER SUPPLY CHARACTERISTICS No-Load Supply Current, (Note 7) Shutdown Supply Current ISHDN232 ON/OFF = SELX = GND, LB = VCC, (SPX = VL, DENX = GND if QFN) ISHDN485 ON/OFF = DEX = GND, SELX = LB = VCC, (SPX = GND, DENX = VL if QFN) ESD CHARACTERISTICS Bus Pins (A, B, Y, Z) Any Mode Human Body Model 25 - All Other Pins Human Body Model 25 - ±2.5 - kV Machine Model 25 - ±200 - V 8 FN6362.0 May 27, 2008 ISL3332, ISL3333 Electrical Specifications Test Conditions: VCC = 3.15V to 3.45V, C1 - C4 = 0.1µF, VL = VCC (for QFN only); Unless Otherwise Specified. Typicals are at VCC = 3.3V, TA =+25°C (Note 7) (Continued) PARAMETER SYMBOL TEST CONDITIONS TEMP MIN (°C) (Note 11) TYP MAX (Note 11) UNITS RS-232 DRIVER AND RECEIVER SWITCHING CHARACTERISTICS (SEL = GND, ALL VERSIONS AND SPEEDS) Driver Output Transition Region Slew Rate SR Driver Output Transition Time tr, tf Driver Propagation Delay tDPHL CL ≥ 15pF Full - 20 30 V/µs CL ≤ 2500pF Full 4 9 - V/µs RL = 3kΩ, CL = 2500pF, 10% - 90% Full 0.22 1.2 3.1 µs RL = 3kΩ, CL = 1000pF (Figure 6) Full - 1 2 µs Full - 1.2 2 µs RL = 3kΩ, Measured From 3V to -3V or -3V to 3V tDPLH Driver Propagation Delay Skew tDSKEW tDPHL - tDPLH (Figure 6) Full - 300 450 ns Driver Enable Time (QFN Only) tDEN CL = 1000pF 25 - 1500 - ns Driver Disable Time (QFN Only) tDDIS RL = 5kΩ, Measured at VOUT = ±3V, CL = 30pF 25 - 500 - ns VOUT = ±3.0V, CL = 1000pF 25 - 25 - µs Full 250 400 - kbps Driver Enable Time from Shutdown tDENSD Driver Maximum Data Rate DRD RL = 3kΩ, CL = 500pF, One Transmitter Switching on Each Port Receiver Propagation Delay tRPHL CL = 15pF (Figure 7) Full - 40 120 ns Full - 58 120 ns tRPHL - tRPLH (Figure 7) Full - 18 40 ns tRPLH Receiver Propagation Delay Skew tRSKEW Receiver Maximum Data Rate DRR CL = 15pF Full 0.46 2 - Mbps Receiver Enable to Output Low tZL QFN Only, CL = 15pF, SW = VCC Full - 18 - ns Receiver Enable to Output High tZH QFN Only, CL = 15pF, SW = GND Full - 18 - ns Receiver Disable from Output Low tLZ QFN Only, CL = 15pF, SW = VCC Full - 22 - ns Receiver Disable from Output High tHZ QFN Only, CL = 15pF, SW = GND Full - 22 - ns Receiver Enable from Shutdown to Output Low tZLSHDN CL = 15pF, SW = VCC 25 - 60 - ns Receiver Enable from Shutdown to Output High tZHSHDN CL = 15pF, SW = GND 25 - 20 - ns RS-485 DRIVER SWITCHING CHARACTERISTICS (FAST DATA RATE (20Mbps), SEL = VCC, ALL VERSIONS (SPA = VCC if QFN)) Driver Differential Input to Output Delay Driver Output Skew Driver Differential Rise or Fall Time tDLH, tDHL RDIFF = 54Ω, CL = 100pF (Figure 2) Full 10 20 35 ns tSKEW RDIFF = 54Ω, CL = 100pF (Figure 2) Full - 2 10 ns tR, tF RDIFF = 54Ω, CL = 100pF, (Figure 2) Full 3 20 30 ns Full - 28 60 ns Driver Enable to Output Low tZL CL = 100pF, SW = VCC (Figure 3) Driver Enable to Output High tZH CL = 100pF, SW = GND (Figure 3) Full - 35 60 ns Driver Disable from Output Low tLZ CL = 15pF, SW = VCC (Figure 3) Full - 30 60 ns tHZ Driver Disable from Output High CL = 15pF, SW = GND (Figure 3) Full - 30 60 ns Driver Enable from Shutdown to Output Low tZL(SHDN) RL = 500Ω, CL = 100pF, SW = VCC (Figure 3) Full - 100 250 ns Driver Enable from Shutdown to Output High tZH(SHDN) RL = 500Ω, CL = 100pF, SW = GND (Figure 3) Full - 290 375 ns Full 20 35 - Mbps Driver Maximum Data Rate fMAX RDIFF = 54Ω, CL = 100pF (Figure 2) RS-485 DRIVER SWITCHING CHARACTERISTICS (MEDIUM DATA RATE (460kbps, QFN ONLY), SEL = VCC, SPA = SPB= GND) Driver Differential Input to Output Delay Driver Output Skew Driver Differential Rise or Fall Time Driver Enable to Output Low tDLH, tDHL RDIFF = 54Ω, CL = 100pF (Figure 2) Full 200 500 1000 ns tSKEW RDIFF = 54Ω, CL = 100pF (Figure 2) Full - 10 150 ns tR, tF RDIFF = 54Ω, CL = 100pF (Figure 2) Full 300 660 1100 ns CL = 100pF, SW = VCC (Figure 3) Full - 42 100 ns tZL 9 FN6362.0 May 27, 2008 ISL3332, ISL3333 Electrical Specifications PARAMETER Test Conditions: VCC = 3.15V to 3.45V, C1 - C4 = 0.1µF, VL = VCC (for QFN only); Unless Otherwise Specified. Typicals are at VCC = 3.3V, TA =+25°C (Note 7) (Continued) SYMBOL TEST CONDITIONS TEMP MIN (°C) (Note 11) TYP MAX (Note 11) UNITS Driver Enable to Output High tZH CL = 100pF, SW = GND (Figure 3) Full - 350 450 ns Driver Disable from Output Low tLZ CL = 15pF, SW = VCC (Figure 3) Full - 30 60 ns Driver Disable from Output High tHZ CL = 15pF, SW = GND (Figure 3) Full - 30 60 ns Driver Enable from Shutdown to Output Low tZL(SHDN) RL = 500Ω, CL = 100pF, SW = VCC (Figure 3) Full - - 500 ns Driver Enable from Shutdown to Output High tZH(SHDN) RL = 500Ω, CL = 100pF, SW = GND (Figure 3) Full - - 750 ns Full 460 2000 - kbps Driver Maximum Data Rate fMAX RDIFF = 54Ω, CL = 100pF (Figure 2) RS-485 DRIVER SWITCHING CHARACTERISTICS (SLOW DATA RATE (115kbps, QFN ONLY), SEL = VCC, SPA = GND, SPB= VCC) Driver Differential Input to Output Delay Driver Output Skew Driver Differential Rise or Fall Time tDLH, tDHL RDIFF = 54Ω, CL = 100pF (Figure2) Full 800 1600 2500 ns tSKEW RDIFF = 54Ω, CL = 100pF (Figure2) Full - 250 500 ns tR, tF RDIFF = 54Ω, CL = 100pF (Figure 2) Full 1000 1700 3100 ns Driver Enable to Output Low tZL CL = 100pF, SW = VCC (Figure 3) Full - 45 100 ns Driver Enable to Output High tZH CL = 100pF, SW = GND (Figure 3) Full - 900 1200 ns Driver Disable from Output Low tLZ CL = 15pF, SW = VCC (Figure 3) Full - 35 60 ns Driver Disable from Output High tHZ CL = 15pF, SW = GND (Figure 3) Full - 25 60 ns Driver Enable from Shutdown to Output Low tZL(SHDN) RL = 500Ω, CL = 100pF, SW = VCC (Figure 3) Full - - 800 ns Driver Enable from Shutdown to Output High tZH(SHDN) RL = 500Ω, CL = 100pF, SW = GND (Figure 3) Full - - 1500 ns Full 115 800 - kbps Full 20 45 70 ns Full - 3 10 ns Driver Maximum Data Rate fMAX RDIFF = 54Ω, CL = 100pF (Figure 2) RS-485 RECEIVER SWITCHING CHARACTERISTICS (SEL = VCC, ALL VERSIONS AND SPEEDS) Receiver Input to Output Delay tPLH, tPHL (Figure 4) Receiver Skew | tPLH - tPHL | tSKEW (Figure 4) Receiver Maximum Data Rate fMAX Full 20 40 - Mbps Receiver Enable to Output Low tZL QFN Only, CL = 15pF, SW = VCC (Figure 5) Full - 20 60 ns Receiver Enable to Output High tZH QFN Only, CL = 15pF, SW = GND (Figure5) Full - 20 60 ns Receiver Disable from Output Low tLZ QFN Only, CL = 15pF, SW = VCC (Figure 5) Full - 20 60 ns Receiver Disable from Output High tHZ QFN Only, CL = 15pF, SW = GND (Figure 5) Full - 20 60 ns Receiver Enable from Shutdown to Output Low tZLSHDN CL = 15pF, SW = VCC (Figure 5) Full - 500 900 ns Receiver Enable from Shutdown to Output High tZHSHDN CL = 15pF, SW = GND (Figure 5) Full - 500 900 ns NOTES: 7. 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. 8. Supply current specification is valid for loaded drivers when DE = 0V (RS-485 mode) or DEN = 0V (RS-232 mode). 9. Applies to peak current. See “Typical Performance Curves” for more information. 10. RIN defaults to RS-485 mode (>15kΩ) when the device is unpowered (VCC = 0V), or in SHDN, regardless of the state of the SEL inputs. 11. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization and are not production tested. 10 FN6362.0 May 27, 2008 ISL3332, ISL3333 Test Circuits and Waveforms R VCC DE DY Y RD D VOD Z VOC R FIGURE 1. RS-485 DRIVER VOD AND VOC TEST CIRCUIT 3V DY VCC 1.5V 0V CL = 100pF DE DY 1.5V tPLH tPHL VOH Y RDIFF D Z 50% OUT (Z) 50% VOL CL = 100pF tPLH tPHL SIGNAL GENERATOR VOH OUT (Y) 50% 50% VOL tDLH 90% DIFF OUT (Z - Y) 10% tDHL 0V 0V 10% tR FIGURE 2A. TEST CIRCUIT +VOD 90% -VOD tF SKEW = |tPLH (Y or Z) - tPHL (Z or Y)| FIGURE 2B. MEASUREMENT POINTS FIGURE 2. RS-485 DRIVER PROPAGATION DELAY AND DIFFERENTIAL TRANSITION TIMES 11 FN6362.0 May 27, 2008 ISL3332, ISL3333 Test Circuits and Waveforms (Continued) DE Y DY 500Ω VCC D SIGNAL GENERATOR SW Z GND ENABLED DE (ON/OFF FOR SHDN) 3V 1.5V 1.5V 0V CL tZH tZH(SHDN) OUTPUT HIGH OUT (Y, Z) FOR SHDN TESTS, SWITCH ON/OFF RATHER THAN DE PARAMETER ON/DE OUTPUT DY SW tHZ 1/- Y/Z 0/1 GND 15 tLZ 1/- Y/Z 1/0 VCC 15 tZH 1/- Y/Z 0/1 GND 100 tZL 1/- Y/Z 1/0 VCC 100 tZH(SHDN) -/1 Y/Z 0/1 GND 100 tZL(SHDN) -/1 Y/Z 1/0 VCC 100 tHZ VOH - 0.5V VOH 2.3V 0V CL (pF) tZL tZL(SHDN) tLZ VCC OUT (Y, Z) 2.3V OUTPUT LOW VOL + 0.5V V OL FIGURE 3B. MEASUREMENT POINTS FIGURE 3A. TEST CIRCUIT FIGURE 3. RS-485 DRIVER ENABLE AND DISABLE TIMES RXEN (QFN ONLY) 0V +1.5V 15pF A RA R B B 0V 0V -1.5V tPLH tPHL VCC SIGNAL GENERATOR RA 1.5V 1.5V 0V FIGURE 4B. MEASUREMENT POINTS FIGURE 4A. TEST CIRCUIT FIGURE 4. RS-485 RECEIVER PROPAGATION DELAY RXEN (QFN ONLY) A R SIGNAL GENERATOR 1kΩ RA VCC SW B ON/OFF (FOR SHDN TESTS) 0V ENABLED GND 15pF 3V 1.5V RXEN (QFN ONLY) 1.5V 3V 1.5V 0V tZH tZH(SHDN) FOR SHDN TESTS, SWITCH ON/OFF RATHER THAN RXEN PARAMETER ON/RXEN B tHZ VOH - 0.5V VOH SW tHZ (QFN Only) 1/- +1.5V GND tLZ (QFN Only) 1/- -1.5V VCC tZH (QFN Only) 1/- +1.5V GND tZL (QFN Only) 1/- -1.5V VCC tZH(SHDN) -/0 +1.5V GND tZL(SHDN) -/0 -1.5V VCC FIGURE 5A. TEST CIRCUIT OUTPUT HIGH RA 1.5V 0V tZL tZL(SHDN) RA tLZ VCC 1.5V OUTPUT LOW VOL + 0.5V V OL FIGURE 5B. MEASUREMENT POINTS FIGURE 5. RS-485 RECEIVER ENABLE AND DISABLE TIMES 12 FN6362.0 May 27, 2008 ISL3332, ISL3333 Test Circuits and Waveforms (Continued) VCC 3V DEN (QFN ONLY) DY,Z DY,Z 1.5V CL Y, Z D 1.5V 0V tDPHL RL SIGNAL GENERATOR tDPLH VO+ OUT (Y,Z) 0V 0V VO- SKEW = |tDPHL - tDPLH| FIGURE 6B. MEASUREMENT POINTS FIGURE 6A. TEST CIRCUIT FIGURE 6. RS-232 DRIVER PROPAGATION DELAY AND TRANSITION TIMES 3V RXEN (QFN ONLY) A, B R RA, RB A, B 50% 50% CL = 15pF 0V tRPLH tRPHL SIGNAL GENERATOR VOH RA, RB 50% 50% SKEW = |tRPHL - tRPLH| FIGURE 7A. TEST CIRCUIT VOL FIGURE 7B. MEASUREMENT POINTS FIGURE 7. RS-232 RECEIVER PROPAGATION DELAY AND TRANSITION TIMES 13 FN6362.0 May 27, 2008 ISL3332, ISL3333 Typical Application Detailed Description RS-232 to RS-485 Converter Each of the two ISL333X ports supports dual protocols: RS-485/422, and RS-232. RS-485 and RS-422 are differential (balanced) data transmission standards for use in high speed (up to 20Mbps) networks, or long haul and noisy environments. The differential signaling, coupled with RS-485’s requirement for an extended common mode range (CMR) of +12V to -7V make these transceivers extremely tolerant of ground potential differences, as well as voltages induced in the cable by external fields. Both of these effects are real concerns when communicating over the RS-485/422 maximum distance of 4000’ (1220m). It is important to note that the ISL333X don’t follow the RS-485 convention whereby the inverting I/O is labeled “B/Z”, and the non inverting I/O is “A/Y”. Thus, in the application diagrams below the 333X A/Y (B/Z) pins connect to the B/Z (A/Y) pins of the generic RS-485/RS-422 ICs. The ISL3332, ISL3333 are ideal for implementing a single IC 2-wire (Tx Data, Rx Data) protocol converter, because each port can be programmed for a different protocol. Figure 8 illustrates the simple connections to create a single transceiver RS-232 to RS-485 converter. Depending on the RS-232 data rate, using an RS-422 bus as an RS-232 “extension cord” can extend the transmission distance up to 4000’ (1220m). A similar circuit on the other end of the cable completes the conversion to/from RS-232. +3.3V + 0.1µF C1 0.1µF + 1 26 C1+ C2 0.1µF 2 C128 C2+ + 27 C2- NC 4 A1 TxD RS-232 IN 5 B1 VCC V- 15 R 5kΩ R 5kΩ NC RxD RS-232 OUT 6 Y1 D 7 Z1 D 8 VCC 9 C4 0.1µF + RA1 24 NC RS-422 is typically a point-to-point (one driver talking to one receiver on a bus), or a point-to-multipoint (multidrop) standard that allows only one driver and up to 10 receivers on each bus. Because of the one driver per bus limitation, RS-422 networks use a two bus, full duplex structure for bidirectional communication, and the Rx inputs and Tx outputs (no tri-state required) connect to different busses, as shown in Figure 10. RB1 25 DY1 22 DZ1 23 11 Y2 10 Z2 20 ON/OFF SEL2 R 12 B2 RS-485 OUT +C3 0.1µF SEL1 13 A2 RS-485 IN 3 V+ D Conversely, RS-485 is a true multipoint standard, which allows up to 32 devices (any combination of drivers- must be tri-statable - and receivers) on each bus. Now bidirectional communication takes place on a single bus, so the Rx inputs and Tx outputs of a port connect to the same bus lines, as shown in Figure 9. Each port set to RS-485 /422 mode includes one Rx and one Tx.RS-232 is a point-to-point, singled ended (signal voltages referenced to GND) communication protocol targeting fairly short (<150’, 46m) and low data rate (<1Mbps) applications. Each port contains two transceivers (2 Tx and 2 Rx) in RS-232 mode. Protocol selection is handled via a logic pin (SELX) for each port. VCC RA2 17 DY2 19 DE2 18 VCC GND 14 NOTE: PINOUT FOR SSOP FIGURE 8. SINGLE IC RS-232 TO RS-485 CONVERTER + GENERIC 1/2 DUPLEX 485 XCVR +3.3V ISL333X RA R +5V B DI GENERIC 1/2 DUPLEX 485 XCVR +5V D 0.1µF + VCC GND VCC RO R B/Z Tx/Rx RE A/Y DE DY DE R 0.1µF A RXEN * RE 0.1µF + VCC RO D DE B/Z Y D A/Y Z GND RT RT DI GND * QFN ONLY FIGURE 9. TYPICAL HALF DUPLEX RS-485 NETWORK 14 FN6362.0 May 27, 2008 ISL3332, ISL3333 + GENERIC 422 Rx (SLAVE) DY GENERIC FULL DUPLEX 422 XCVR (SLAVE) +5V R + ISL333X (MASTER) RE 0.1µF +3.3V 1kΩ OR NC RO 0.1µF +5V VCC GND B A DE Z A Y B RA RO R Z RT A R VCC RT VCC D 0.1µF + B D Y DI GND GND FIGURE 10. TYPICAL RS-422 NETWORK . ISL333x Advantages These dual protocol ICs offer many parametric improvements vs those offered on competing dual protocol devices. Some of the major improvements are: • 3.3V Supply Voltage - Eliminates the 5V supply that powers just the interface IC • 15kV Bus Pin ESD - Eases board level requirements • Full Failsafe RS-485 Rx - Eliminates bus biasing • Selectable RS-485 Data Rate - Up to 20Mbps, or slew rate limited for low EMI and fewer termination issues • High RS-232 Data Rate - >250kbps • Lower Tx and Rx Skews - Wider, consistent bit widths • Lower ICC - Max ICC is 2x to -4x lower than competition • Flow-Thru Pinouts - Tx, Rx bus pins on one side/logic pins on the other, for easy routing to connector/UART Packaging - Smaller (QFN) and Pb-free. RS-232 Mode Rx Features RS-232 receivers invert and convert RS-232 input levels (±3V to ±25V) to the standard TTL/CMOS levels required by a UART, ASIC, or µcontroller serial port. Receivers are designed to operate at faster data rates than the drivers, and they feature very low skews (18ns) so the receivers contribute negligibly to bit width distortion. Inputs include the standards required 3kΩ to 7kΩ pull-down resistor, so unused inputs may be left unconnected. Rx inputs also have built-in hysteresis to increase noise immunity, and to decrease erroneous triggering due to slowly transitioning input signals. Rx outputs are short circuit protected, and are only tristatable when the entire IC is shutdown (SHDN) via the 15 ON/OFF pin, or via the active low RXEN pins available on the QFN package option (see “ISL3333 Special Features” for more details). Tx Features RS-232 drivers invert and convert the standard TTL/CMOS levels from a UART, or µcontroller serial port to RS-232 compliant levels (±5V minimum). The Tx delivers these compliant output levels even at data rates of 400kbps, with loads of 500pF, and with one output in each port switching at this high rate. The drivers are designed for low skew (typically 12% of the 400kbps bit width), and are compliant to the RS-232 slew rate spec (4 to 30V/μs) for a wide range of load capacitances. Tx inputs float if left unconnected, and may cause ICC increases. For the best results, connect unused inputs to GND. Tx outputs are short circuit protected, and incorporate a thermal SHDN feature to protect the IC in situations of severe power dissipation - see the RS-485 section for more details. All drivers disable in SHDN, or when the 3.3V power supply is off, and a port’s drivers also disable via the corresponding DENX pin (see “ISL3333 Special Features” for more details) available on the QFN package option (see Tables 2 and 3 and the “Low Power Shutdown” section). The ISL3332’s SHDN function is useful for disabling the outputs if both ports will always be disabled together (e.g., used as a four transceiver RS-232 port), and if it is acceptable for the Rx to be disabled as well. Charge Pumps The on-chip charge pumps create the RS-232 transmitter power supplies (typically +5.7/-5.3V) from a single supply as low as 3.15V, and are enabled only if either port is configured for RS-232 operation. The efficient design requires only four small 0.1μF capacitors for the voltage doubler and inverter functions. By operating discontinuously (i.e., turning off as soon as V+ and V- pump up to the FN6362.0 May 27, 2008 ISL3332, ISL3333 nominal values), the charge pump contribution to RS-232 mode ICC is reduced significantly. Unlike competing devices that require the charge pump in RS-485 mode, disabling the charge pump saves power, and minimizes noise. If the application keeps both ports in RS-485 mode (e.g., a dedicated dual channel RS-485 interface), then the charge pump capacitors aren’t even required. Data Rates and Cabling Drivers operate at data rates up to 400kbps, and are guaranteed for data rates up to 250kbps. The charge pumps and drivers are designed such that one driver in each port can be operated at the rated load, and at 250kbps (see Figure 34). Figure 34 also shows that drivers can easily drive two to three thousand picofarads at data rates up to 250kbps, while still delivering compliant ±5V output levels. Receivers operate at data rates up to 2Mbps. They are designed for a higher data rate to facilitate faster factory downloading of software into the final product, thereby improving the user’s manufacturing throughput. Figures 37 and 38 illustrate driver and receiver waveforms at 250kbps, and 500kbps, respectively. For these graphs, one driver of each port drives the specified capacitive load, and a receiver in the port. RS-232 doesn’t require anything special for cabling; just a single bus wire per transmitter and receiver, and another wire for GND. So an ISL333X RS-232 port uses a five conductor cable for interconnection. Bus terminations are not required, nor allowed, by the RS-232 standard. RS-485 Mode Rx Features RS-485 receivers convert differential input signals as small as 200mV, as required by the RS-485 and RS-422 standards, to TTL/CMOS output levels. The differential Rx provides maximum sensitivity, noise immunity, and common mode rejection. Per the RS-485 standard, receiver inputs function with common mode voltages as great as +12V and -7V, regardless of supply voltage, making them ideal for long networks where induced voltages are a realistic concern. Each RS-485/RS-422 port includes a single receiver (RA), and the unused Rx output (RB) is disabled but pulled high by an internal current source. The internal current source turns off in SHDN. Worst case receiver input currents are 20% lower than the 1 “unit load” (1mA) RS-485 limit, which translates to a 15kΩ minimum input resistance. These receivers include a “full fail-safe” function that guarantees a high level receiver output if the receiver inputs are unconnected (floating), shorted together, or if the bus is terminated but undriven (i.e., differential voltage collapses to near zero due to termination). Failsafe with shorted, or terminated and undriven inputs is accomplished by setting 16 the Rx upper switching point at -40mV, thereby ensuring that the Rx recognizes a 0V differential as a high level. All the Rx outputs are short circuit protected, and are tri-state when the IC is forced into SHDN, but ISL3332 (SSOP) receiver outputs are not independently tri-statable. ISL3333 (QFN) receiver outputs are tri-statable via an active low RXEN input for each port (see “ISL3333 Special Features” for more details). Tx Features The RS-485/RS-422 driver is a differential output device that delivers at least 1.5V across a 54Ω load (RS-485), and at least 2V across a 100Ω load (RS-422). The drivers feature low propagation delay skew to maximize bit widths, and to minimize EMI. To allow multiple drivers on a bus, the RS-485 spec requires that drivers survive worst case bus contentions undamaged. The ISL333X drivers meet this requirement via driver output short circuit current limits, and on-chip thermal shutdown circuitry. The output stages incorporate current limiting circuitry that ensures that the output current never exceeds the RS-485 spec, even at the common mode voltage range extremes of 12V and -7V. In the event of a major short circuit condition, devices also include a thermal shutdown feature that disables the drivers whenever the die temperature becomes excessive. This eliminates the power dissipation, allowing the die to cool. The drivers automatically re-enable after the die temperature drops about 15 degrees. If the contention persists, the thermal shutdown/re-enable cycle repeats until the fault is cleared. Receivers stay operational during thermal shutdown. RS-485 multi-driver operation also requires drivers to include tri-state functionality, so each port has a DE pin to control this function. If the driver is used in an RS-422 network, such that driver tri-state isn’t required, then the DE pin can be left unconnected and an internal pull-up keeps it in the enabled state. Drivers are also tri-stated when the IC is in SHDN, or when the 3.3V power supply is off. Speed Options The ISL3332 (SSOP) has fixed, high slew rate driver outputs optimized for 20Mbps data rates. The ISL3333 (QFN) offers three user selectable data rate options: “Fast” for high slew rate and 20Mbps; “Medium” with slew rate limiting set for 460kbps; “Slow” with even more slew rate limiting for 115kbps operation. See the “Data Rate“ and “Slew Rate Limited Data Rates” sections for more information. Receiver performance is the same for all three speed options. Data Rate, Cables, and Terminations RS-485/RS-422 are intended for network lengths up to 4000’ (1220m), but the maximum system data rate decreases as the transmission length increases. Devices operating at the maximum data rate of 20Mbps are limited to maximum lengths of 20-100’ (6-31m), while devices operating at or FN6362.0 May 27, 2008 ISL3332, ISL3333 Higher data rates require faster edges, so both the ISL333X versions offer an edge rate capable of 20Mbps data rates. The ISL3333 also offers two slew rate limited edge rates to minimize problems at slower data rates. Nevertheless, for the best jitter performance when driving long cables, the faster speed settings may be preferable, even at low data rates. See the “RS-485 Slew Rate Limited Data Rates” section for details. Twisted pair is the cable of choice for RS-485/RS-422 networks. Twisted pair cables tend to pick up noise and other electromagnetically induced voltages as common mode signals, which are effectively rejected by the differential receivers in these ICs. The preferred cable connection technique is “daisychaining”, where the cable runs from the connector of one device directly to the connector of the next device, such that cable stub lengths are negligible. A “backbone” structure, where stubs run from the main backbone cable to each device’s connector, is the next best choice, but care must be taken to ensure that each stub is electrically “short”. See Table 4 for recommended maximum stub lengths for each speed option. TABLE 4. RECOMMENDED STUB LENGTHS SPEED OPTION MAXIMUM STUB LENGTH ft (m) SLOW 350-500 (107-152) MED 100-150 (30.5 - 46) FAST 1-3 (0.3 - 0.9) Proper termination is imperative to minimize reflections when using the 20Mbps speed option. Short networks using the medium and slow speed options need not be terminated, but terminations are recommended unless power dissipation is an overriding concern. Note that the RS-485 spec allows a maximum of two terminations on a network, otherwise the Tx output voltage may not meet the required VOD. In point-to-point, or point-to-multipoint (RS-422) networks, the main cable should be terminated in its characteristic impedance (typically 120Ω) at the end farthest from the driver. In multi-receiver applications, stubs connecting receivers to the main cable should be kept as short as possible, but definitely shorter than the limits shown in Table 4. Multipoint (RS-485) systems require that the main cable be terminated in its characteristic impedance at both ends. Again, keep stubs connecting a transceiver to the main cable as short as possible, and refer to Table 4. Avoid “star”, and other configurations, where there are many “ends” which would require more than the two allowed terminations to prevent reflections. 17 High ESD All pins on the ISL333X include ESD protection structures rated at ±2.5kV (HBM), which is good enough to survive ESD events commonly seen during manufacturing. But the bus pins (Tx outputs and Rx inputs) are particularly vulnerable to ESD events because they connect to an exposed port on the exterior of the finished product. Simply touching the port pins, or connecting a cable, can destroy an unprotected port. ISL333X bus pins are fitted with advanced structures that deliver ESD protection in excess of ±15kV (HBM), without interfering with any signal in the RS-485 or the RS-232 range. This high level of protection may eliminate the need for board level protection, or at the very least will increase the robustness of any board level scheme. Small Packages Competing 3.3V dual protocol ICs are available only in a 28 Ld SSOP. The ISL3333’s tiny 6x6mm QFN footprint is 80% smaller than the competing SSOP. Flow Through Pinouts Even the ISL333X pinouts are features, in that the true flow-through design simplifies board layout. Having the bus pins all on one side of the package for easy routing to a cable connector, and the Rx outputs and Tx inputs (logic pins) on the other side for easy connection to a UART, avoids costly and problematic crossovers. Competing “flow through” pinouts mix logic and bus pin inputs on one side of the package, and logic and bus pin outputs on the other side. This forces the designer to route four traces from the right side of the IC around the IC to the cable connector. Figure 11 illustrates the flow-through nature of the ISL333X’s pinout. ISL3332 A1 B1 CONNECTOR below 115kbps can operate at the maximum length of 4000’ (1220m). Y1 Z1 Z2 Y2 B2 A2 UART R D RA1 OR DY1 ASIC OR DY2 µCONTROLLER RA2 FIGURE 11. ILLUSTRATION OF FLOW THROUGH PINOUT Low Power Shutdown (SHDN) Mode The ON/OFF pin is driven low to place the IC (both ports) in the SHDN mode, and the already low supply current drops to as low as 21μA. If this functionality isn’t desired, the pin can be left disconnected (thanks to the internal pull-up), or it should be connected to VCC (VL for the QFN), through a 1kΩ resistor. SHDN disables the Tx and Rx outputs, and disables the charge pumps if either port is in RS-232 mode, so V+ collapses to VCC, and V- collapses to GND. FN6362.0 May 27, 2008 ISL3332, ISL3333 All but 10uA of SHDN supply current (ICC plus IL) is due to control input (ON, LB, SP, DE, DEN) pull-up resistors (~11μA/resistor), so SHDN supply current varies depending on the ISL333X configuration. The spec tables indicate the SHDN currents for configurations that optimize these currents. For example, in RS-232 mode the SP pins aren’t used, so if both ports are configured for RS-232, floating or tying the SP pins high minimizes SHDN current. Likewise in RS-485 mode, the drivers are disabled in SHDN, so driving the DE and DEN pins high during this time also reduces the supply current. When enabling from SHDN in RS-232 mode, allow at least 25μs for the charge pumps to stabilize before transmitting data. The charge pumps aren’t used in RS-485 mode, so the transceiver is ready to send or receive data in less than 2µs, which is much faster than competing devices that require the charge pump for all modes of operation. VCC = +3.3V RA DY GND VCC = +2V VOH = 3.3V RXD VIH ≥ 2 VOH ≤ 2 ISL3332 ESD DIODE TXD GND UART/PROCESSOR VCC = +3.3V VCC = +2V VL RA Internal Loopback Mode VOH = 2V RXD ESD DIODE Driving the LB pin low places both ports in the loopback mode, a mode that facilitates implementing board level self test functions. In loopback, internal switches disconnect the Rx inputs from the Rx outputs, and feed back the Tx outputs to the appropriate Rx output. This way the data driven at the Tx input appears at the corresponding Rx output (refer to “Typical Operating Circuits” on page 6”). The Tx outputs remain connected to their terminals, so the external loads are reflected in the loopback performance. This allows the loopback function to potentially detect some common bus faults such as one or both driver outputs shorted to GND, or outputs shorted together. with the logic device output levels. Tailoring the logic pin input switching points and output levels to the supply voltage of the UART, ASIC, or μcontroller eliminates the need for a level shifter/translator between the two ICs. Note that the loopback mode uses an additional set of receivers, as shown in the “Typical Operating Circuits”. These loopback receivers are not standards compliant, so the loopback mode can’t be used to implement a half-duplex RS-485 transceiver. VL can be anywhere from VCC down to 1.2V, but the input switching points may not provide enough noise margin when VL < 1.5V. Table 5 indicates typical VIH and VIL values for various VL voltages so the user can ascertain whether or not a particular VL voltage meets his needs. If loopback won’t be utilized, the pin can be left disconnected (thanks to the internal pull-up), or it should be connected to VCC (VL for the QFN), through a 1kΩ resistor. TABLE 5. VIH AND VIL vs. VL FOR VCC = 3.3V DY GND VIH = 1V VOH ≤ 2 ISL3333 TXD GND UART/PROCESSOR FIGURE 12. USING VL PIN TO ADJUST LOGIC LEVELS VL (V) VIH (V) VIL (V) 1.2 0.85 0.26 ISL3333 (QFN Package) Special Features 1.5 0.9 0.5 Logic Supply (VL Pin) 1.8 0.9 0.73 The ISL3333 (QFN) includes a VL pin that powers the logic inputs (Tx inputs and control pins) and Rx outputs. These pins interface with “logic” devices such as UARTs, ASICs, and μcontrollers, and today most of these devices use power supplies significantly lower than 3.3V. Thus, a 3.3V output level from a 3.3V powered dual protocol IC might seriously overdrive and damage the logic device input. Similarly, the logic device’s low VOH might not exceed the VIH of a 3.3V powered dual protocol input. Connecting the VL pin to the power supply of the logic device (Figure 12) limits the ISL3333’s Rx output VOH to VL (Figure 15), and reduces the Tx and control input switching points to values compatible 2.3 1.2 1.0 2.7 1.4 1.3 3.3 1.8 1.7 18 Note: With VL ≤ 1.6V, the ISL3333 may not operate at the full data rate unless the logic signal VIL is at least 0.2V below the typical value listed in Table 5. The VL supply current (IL) is typically less than 80μA, even in the worst case configuration, as shown in Figures 20 and 21. With the Rx outputs unloaded, all of the DC VL current is due to inputs with internal pull-up resistors (DE, DEN, SP, LB, FN6362.0 May 27, 2008 ISL3332, ISL3333 ON/OFF) being driven to the low input state. The worst case IL current occurs during SHDN (see Figure 21), due to the IL through the ON/OFF pin pull-up resistor when that pin is driven low. IIL through an input pull-up resistor is ~11µA (6µA for DE1 and DE2), so the IL in Figure 20 drops by about 22µA (at VL = 3.3V) when the two SP inputs are high versus low (next to bottom vs. top curve). SHDN IL is lowest in the RS-232 mode, because only the DEN pins and/or the ON/OFF pin should be driven low. When all the inputs with pull-downs are driven high, IL drops to <<1µA (see Figure 20), so to minimize power dissipation drive these inputs high when unneeded (e.g., SP inputs aren’t used in RS-232 mode, and DEN inputs aren’t used in RS-485 mode, so drive them high in those modes). +3.3V ISL3330 RA A DEN Y DY D The DENX pin is ignored if the corresponding port is set for RS-485 mode, and it is internally pulled high. Active Low Rx Enable (RXEN) In many RS-485 applications, especially half duplex configurations, users like to accomplish “echo cancellation” by disabling the corresponding receiver while its driver is transmitting data. This function is available on the QFN package via an active low RXEN pin for each port. The active low function also simplifies direction control, by allowing a single Tx/Rx direction control line. If an active high RXEN were used, either two valuable I/O pins would be used for direction control, or an external inverter is required between DE and RXEN. Figure 13 details the advantage of using the RXEN pin. RS-485 Slew Rate Limited Data Rates The SSOP version of this IC operates with Tx output transitions optimized for a 20Mbps data rate. These fast edges may increase EMI and reflection issues, even though fast transitions aren’t required at the lower data rates used by many applications. The ISL3333 (QFN version) solves this problem by offering two additional, slew rate limited, data rates that are optimized for speeds of 115kbps, and 460kbps.The slew limited edges permit longer unterminated networks, or longer stubs off terminated busses, and help 19 Z GND ACTIVE HIGH RX ENABLE +3.3V ISL3333 + VCC RA R 0.1µF B A RXEN * The ISL3333 also adds an RS-232 mode Tx enable pin (DENX) for each port. Driving one of these pins low disables both drivers in the corresponding port. Because RS-232 is a point-to-point (only one Tx allowed on the bus) standard, the main use for this disable function is to reduce power by eliminating the load current (approximately 1mA per Tx output) through the 5kΩ resistor in the Rx at the cable’s far end. The ICC in this mode is still considerably higher than in SHDN, but the enable time from Tx disable is much faster (1.5µs vs. 25µs) than the enable time from SHDN due to the charge pumps remaining on during Tx disable. 0.1µF B R RXEN Tx/Rx QFN logic input pins that are externally tied high in an application, should use the VL supply for the high voltage level. RS-232 Mode Tx Enable/Disable (DEN) + VCC Tx/Rx DE DY Y D Z GND * QFN ONLY ACTIVE LOW RX ENABLE FIGURE 13. USING ACTIVE LOW vs ACTIVE HIGH RX ENABLE minimize EMI and reflections. Nevertheless, for the best jitter performance when driving long cables, the faster speed options may be preferable, even at lower data rates. The faster output transitions deliver less variability (jitter) when loaded with the large capacitance associated with long cables. Of course, faster transitions require more attention to ensuring short stub lengths and quality terminations, so there are trade-offs to be made. Assuming a jitter budget of 10%, it is likely better to go with the slow speed option for data rates of 115kbps or less, to minimize fast edge effects. Likewise, the medium speed option is a good choice for data rates between 115kbps and 460kbps. For higher data rates, or when the absolute best jitter is required, use the high speed option. Speed selection is via the SPA and SPB pins (see Table 3), and the selection pertains to each port programmed for RS-485 mode. Evaluation Board An evaluation board, part number ISL3333EVAL1Z, is available to assist in assessing the dual protocol IC’s performance. The evaluation board contains a QFN packaged device, but because the same die is used in all packages, the board is also useful for evaluating the functionality of the other versions. The board’s design allows for evaluation of all standard features, plus the QFN specific features. Refer to the eval board application note for details, and contact your sales rep for ordering information. FN6362.0 May 27, 2008 ISL3332, ISL3333 Typical Performance Curves VCC = VL = 3.3V, TA = +25°C; Unless Otherwise Specified 3.5 VOL, +25 °C 3.0 VOH, +25 °C 25 20 HIGH OUTPUT VOLTAGE (V) RECEIVER OUTPUT CURRENT (mA) 30 VOL, +85 °C VOH, +85 °C 15 10 5.0 0 2.0 IOH = -0.5mA IOH = -1mA 1.5 IOH = -6mA 1.0 0.5 IOH = -2mA 0 0 1 2 RECEIVER OUTPUT VOLTAGE (V) 3 3.3 DIFFERENTIAL OUTPUT VOLTAGE (V) 80 70 60 50 40 30 20 10 0 0.5 1 1.5 2 1.5 2.5 3 2.25 3.0 3.3 RDIFF = 100Ω 2.20 2.15 2.10 2.05 RDIFF = 54Ω 2.00 1.95 1.9 -40 3.5 -25 250 75 85 4.5 +25 °C +85 °C 0 50 25 TEMPERATURE (°C) FIGURE 17. RS-485, DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs TEMPERATURE FIGURE 16. RS-485, DRIVER OUTPUT CURRENT vs DIFFERENTIAL OUTPUT VOLTAGE RS-232, RXEN = X, DEN = VL (IF QFN) 200 4.0 -40 °C 150 3.5 RS-232, DEN = GND, RXEN = X (QFN ONLY) 100 ICC (mA) OUTPUT CURRENT (mA) 2.5 2.30 DIFFERENTIAL OUTPUT VOLTAGE (V) 50 Y OR Z = LOW 3.0 2.5 0 RS-485, HALF DUPLEX, DE = VCC, RXEN = X Y OR Z = HIGH -50 2.0 +25 °C +85 °C 1.5 -100 -150 2.0 FIGURE 15. RECEIVER HIGH OUTPUT VOLTAGE vs LOGIC SUPPLY VOLTAGE (VL) (QFN ONLY) 90 0 1 VL (V) FIGURE 14. RECEIVER OUTPUT CURRENT vs RECEIVER OUTPUT VOLTAGE DRIVER OUTPUT CURRENT (mA) 2.5 -40 °C -7 -6 -4 -2 0 2 4 6 OUTPUT VOLTAGE (V) 8 10 12 FIGURE 18. RS-485, DRIVER OUTPUT CURRENT vs SHORT CIRCUIT VOLTAGE 20 1 -40 RS-485, DE = GND, RXEN = X -25 RS-485, FULL DUPLEX, DE = VCC, RXEN = X 0 50 25 75 85 TEMPERATURE (°C) FIGURE 19. SUPPLY CURRENT vs TEMPERATURE FN6362.0 May 27, 2008 ISL3332, ISL3333 Typical Performance Curves VCC = VL = 3.3V, TA = +25°C; Unless Otherwise Specified (Continued) 60 100 NO LOAD VIN = VL or GND 50 VL ≤ VCC VL > VCC LB = ON = VL, RXEN = GND 80 5 -48 RS 20 E ,D P =S RS-2 RS-485 10 ,D 32 N= ICC and IL (µA) 30 E ,D ND =G VL GN N= , DE D, S P E = GN V P= L D, S = DE N 60 50 40 30 = VL 20 1.5 2.0 2.5 3.0 3.5 4.0 1.5 2.0 VL (V) FIGURE 20. VL SUPPLY CURRENT vs VL VOLTAGE (QFN ONLY) 1640 = VL RS-232/RS-485 ICC 0 1 0 D GN = DEN RS-232 I L, SP 10 RS-232, DEN = SP = VL 1 = EN =D D GN SP I L, N= E 5 D = -48 SP RS I L, VL 2 3 N= -2 RS , DE ND G P= GN D N= I ,S , DE 485 L V L S = R , SP 32 I L RS-2 70 40 IL (µA) NO LOAD VIN = VL or GND LB = VL ON = DZ/DE = DY = GND 90 2.5 VL (V) 3.0 3.5 4.0 FIGURE 21. VCC and VL SHDN SUPPLY CURRENTS vs VL VOLTAGE (QFN ONLY) 300 RDIFF = 54Ω, CL = 100pF RDIFF = 54Ω, CL = 100pF |tPLHZ - tPHLY| 1630 1620 |tPHLZ - tPLHY| 200 1610 tDHL 1600 1590 SKEW (ns) PROPAGATION DELAY (ns) 250 tDLH 1580 1570 tDHL 150 100 50 1560 |tDLH - tDHL| 1550 -40 0 -25 25 50 75 0 -40 85 0 -25 75 85 FIGURE 23. RS-485, DRIVER SKEW vs TEMPERATURE (SLOW DATA RATE, QFN ONLY) 16 RDIFF = 54Ω, CL = 100pF RDIFF = 54Ω, CL = 100pF 14 545 |tPLHZ - tPHLY| 12 540 10 535 tDHL 530 SKEW (ns) PROPAGATION DELAY (ns) 50 TEMPERATURE (°C) TEMPERATURE (°C) FIGURE 22. RS-485, DRIVER PROPAGATION DELAY vs TEMPERATURE (SLOW DATA RATE, QFN ONLY) 550 25 tDLH 525 tDHL 8 |tPHLZ - tPLHY| 6 4 |tDLH - tDHL| 520 515 -40 2 -25 0 25 TEMPERATURE (°C) 50 75 FIGURE 24. RS-485, DRIVER PROPAGATION DELAY vs TEMPERATURE (MEDIUM DATA RATE, QFN ONLY) 21 85 0 -40 -25 0 25 TEMPERATURE (°C) 50 75 85 FIGURE 25. RS-485, DRIVER SKEW vs TEMPERATURE (MEDIUM DATA RATE, QFN ONLY) FN6362.0 May 27, 2008 ISL3332, ISL3333 Typical Performance Curves 24 VCC = VL = 3.3V, TA = +25°C; Unless Otherwise Specified (Continued) 3.0 RDIFF = 54Ω, CL = 100pF RDIFF = 54Ω, CL = 100pF |tDLH - tDHL| 2.5 22 21 2.0 tDLH 20 SKEW (ns) PROPAGATION DELAY (ns) 23 19 tDHL 18 1.5 |tPHLZ - tPLHY| 1.0 17 0.5 |tPLHZ - tPHLY| 16 0 25 TEMPERATURE (°C) 50 5 5 0 RA 0 DRIVER INPUT (V) RDIFF = 54Ω, CL = 100pF 4 Y 3 2 1 -25 Z 0 RDIFF = 54Ω, CL = 100pF DRIVER OUTPUT (V) 4 Y 3 2 1 Z 0 TIME (200ns/DIV) FIGURE 30. RS-485, DRIVER AND RECEIVER WAVEFORMS, LOW TO HIGH (MEDIUM DATA RATE, QFN ONLY) 22 5 0 5 RA 0 4 Z 3 2 Y 1 0 FIGURE 29. RS-485, DRIVER AND RECEIVER WAVEFORMS, HIGH TO LOW (SLOW DATA RATE, QFN ONLY) RECEIVER OUTPUT (V) 0 RA 0 5 DRIVER INPUT (V) RECEIVER OUTPUT (V) DRIVER OUTPUT (V) 5 85 75 TIME (400ns/DIV) FIGURE 28. RS-485, DRIVER AND RECEIVER WAVEFORMS, LOW TO HIGH (SLOW DATA RATE, QFN ONLY) RDIFF = 54Ω, CL = 100pF 50 DY TIME (400ns/DIV) DY 0 25 TEMPERATURE (°C) FIGURE 27. RS-485, DRIVER SKEW vs TEMPERATURE (FAST DATA RATE) DRIVER OUTPUT (V) DRIVER OUTPUT (V) RECEIVER OUTPUT (V) FIGURE 26. RS-485, DRIVER PROPAGATION DELAY vs TEMPERATURE (FAST DATA RATE) DY 0 -40 85 75 DRIVER INPUT (V) -25 RDIFF = 54Ω, CL = 100pF DY 5 0 RA 0 5 DRIVER INPUT (V) -40 RECEIVER OUTPUT (V) 15 4 Z 3 2 Y 1 0 TIME (200ns/DIV) FIGURE 31. RS-485, DRIVER AND RECEIVER WAVEFORMS, HIGH TO LOW (MEDIUM DATA RATE, QFN ONLY) FN6362.0 May 27, 2008 ISL3332, ISL3333 DY 0 5 RA 0 4 Y 3 2 Z 1 0 RDIFF = 54Ω, CL = 100pF DY RA 0 Z 3 2 Y 1 0 TIME (10ns/DIV) TIME (10ns/DIV) FIGURE 32. RS-485, DRIVER AND RECEIVER WAVEFORMS, LOW TO HIGH (FAST DATA RATE) FIGURE 33. RS-485, DRIVER AND RECEIVER WAVEFORMS, HIGH TO LOW (FAST DATA RATE) 7.5 2.5 400kbps ALL TOUTS LOADED WITH 3kΩ TO GND 0 2 TRANSMITTERS AT 250kbps or 400kbps, OTHER TRANSMITTERS AT 30kbps -2.5 400kbps -5 250kbps VOUT 0 1000 2000 3000 4000 5000 TRANSMITTER OUTPUT VOLTAGE (V) 250kbps VOUT+ 5.0 RS-232 REGION OF NONCOMPLIANCE TRANSMITTER OUTPUT VOLTAGE (V) 7.5 -7.5 0 5 4 5 DRIVER INPUT (V) 5 RECEIVER OUTPUT (V) RDIFF = 54Ω, CL = 100pF DRIVER INPUT (V) VCC = VL = 3.3V, TA = +25°C; Unless Otherwise Specified (Continued) DRIVER OUTPUT (V) DRIVER OUTPUT (V) RECEIVER OUTPUT (V) Typical Performance Curves 5.0 VOUT+ 2.5 OUTPUTS STATIC ALL TOUTS LOADED WITH 3kΩ TO GND AND AT V+ OR V- 0 -2.5 -5 VOUT -7.5 -40 -25 LOAD CAPACITANCE (pF) FIGURE 34. RS-232, TRANSMITTER OUTPUT VOLTAGE vs LOAD CAPACITANCE 0 25 TEMPERATURE (°C) 50 75 85 FIGURE 35. RS-232, TRANSMITTER OUTPUT VOLTAGE vs TEMPERATURE TRANSMITTER OUTPUT CURRENT (mA) 50 CL = 2000pF, 2 CHANNELS SWITCHING 40 5 Y or Z = LOW DY 30 0 20 5 VOUT SHORTED TO GND 10 0 0 -5 Y/A 5 -10 RA Y or Z = HIGH 0 -20 -30 -40 -25 0 25 50 75 85 2µs/DIV. TEMPERATURE (°C) FIGURE 36. RS-232, TRANSMITTER SHORT CIRCUIT CURRENT vs TEMPERATURE 23 FIGURE 37. RS-232, TRANSMITTER AND RECEIVER WAVEFORMS AT 250kbps FN6362.0 May 27, 2008 ISL3332, ISL3333 Typical Performance Curves VCC = VL = 3.3V, TA = +25°C; Unless Otherwise Specified (Continued) 58 CL = 1000pF, 2 CHANNELS SWITCHING VIN = ±5V 57 RECEIVER + DUTY CYCLE (%) 5 DY 0 5 0 Y/A -5 5 RA FULL TEMP RANGE 56 55 SR IN = 15V/µs 54 53 52 51 SR IN = 100V/µs 50 0 49 0 500 VOUT ≥ ±4V AND DUTY CYCLE BETWEEN 40% AND 60% 500 ALL TOUTS LOADED WITH 5kΩ TO GND DATA RATE (kbps) 450 2 TRANSMITTERS AT +25°C 1 TRANSMITTER AT +25°C 300 250 1 TRANSMITTER AT +85°C 200 2 TRANSMITTERS AT +85°C 150 100 7.5 +25°C VOUT+ 5 +85°C 2.5 2 TRANSMITTERS SWITCHING 0 ALL TOUTS LOADED WITH 5kΩ TO GND, CL = 1000pF -2.5 +85°C -5 +25°C VOUT -7.5 0 1000 2000 3000 4000 LOAD CAPACITANCE (pF) 5000 FIGURE 40. RS-232, TRANSMITTER MAXIMUM DATA RATE vs LOAD CAPACITANCE 0 100 200 300 400 DATA RATE (kbps) 500 600 FIGURE 41. RS-232, TRANSMITTER OUTPUT VOLTAGE vs DATA RATE Die Characteristics 650 2 TRANSMITTERS SWITCHING 600 ALL TOUTS LOADED WITH 3kΩ TO GND, CL = 1000pF 550 SKEW (ns) 2000 RS-232 REGION OF NONCOMPLIANCE 550 350 1500 FIGURE 39. RS-232, RECEIVER OUTPUT +DUTY CYCLE vs DATA RATE TRANSMITTER OUTPUT VOLTAGE (V) FIGURE 38. RS-232, TRANSMITTER AND RECEIVER WAVEFORMS AT 400kbps 400 1000 DATA RATE (kbps) 2µs/DIV. +85°C SUBSTRATE AND QFN PAD POTENTIAL (POWERED UP): GND 500 TRANSISTOR COUNT: 450 4838 400 +25°C 350 BiCMOS -40 °C 300 250 PROCESS: 0 50 200 400 600 650 DATA RATE (kbps) FIGURE 42. RS-232, TRANSMITTER SKEW vs DATA RATE 24 FN6362.0 May 27, 2008 ISL3332, ISL3333 Shrink Small Outline Plastic Packages (SSOP) M28.209 (JEDEC MO-150-AH ISSUE B) N 28 LEAD SHRINK SMALL OUTLINE PLASTIC PACKAGE INDEX AREA H 0.25(0.010) M B M INCHES E GAUGE PLANE -B1 2 3 L 0.25 0.010 SEATING PLANE -A- A D -C- α e B C 0.10(0.004) 0.25(0.010) M C A M SYMBOL MIN MAX MIN MAX NOTES A - 0.078 - 2.00 - A1 0.002 - 0.05 - - A2 0.065 0.072 1.65 1.85 - B 0.009 0.014 0.22 0.38 9 C 0.004 0.009 0.09 0.25 - D 0.390 0.413 9.90 10.50 3 E 0.197 0.220 5.00 5.60 4 e A2 A1 B S 0.026 BSC H 0.292 L 0.022 N α NOTES: MILLIMETERS 0.65 BSC 0.322 7.40 0.037 0.55 28 0° - 0.95 6 28 8° 0° - 8.20 7 8° 1. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of Publication Number 95. Rev. 2 6/05 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. 3. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold flash, protrusion and gate burrs shall not exceed 0.20mm (0.0078 inch) per side. 4. Dimension “E” does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.20mm (0.0078 inch) per side. 5. The chamfer on the body is optional. If it is not present, a visual index feature must be located within the crosshatched area. 6. “L” is the length of terminal for soldering to a substrate. 7. “N” is the number of terminal positions. 8. Terminal numbers are shown for reference only. 9. Dimension “B” does not include dambar protrusion. Allowable dambar protrusion shall be 0.13mm (0.005 inch) total in excess of “B” dimension at maximum material condition. 10. Controlling dimension: MILLIMETER. Converted inch dimensions are not necessarily exact. All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 25 FN6362.0 May 27, 2008 ISL3332, ISL3333 Package Outline Drawing L40.6x6 40 LEAD QUAD FLAT NO-LEAD PLASTIC PACKAGE Rev 3, 10/06 4X 4.5 6.00 36X 0.50 A B 6 PIN 1 INDEX AREA 6 PIN #1 INDEX AREA 40 31 30 1 6.00 4 . 10 ± 0 . 15 21 10 0.15 (4X) 11 20 0.10 M C A B TOP VIEW 40X 0 . 4 ± 0 . 1 4 0 . 23 +0 . 07 / -0 . 05 BOTTOM VIEW SEE DETAIL "X" 0.10 C 0 . 90 ± 0 . 1 ( C BASE PLANE ( 5 . 8 TYP ) SEATING PLANE 0.08 C SIDE VIEW 4 . 10 ) ( 36X 0 . 5 ) C 0 . 2 REF 5 ( 40X 0 . 23 ) 0 . 00 MIN. 0 . 05 MAX. ( 40X 0 . 6 ) DETAIL "X" TYPICAL RECOMMENDED LAND PATTERN NOTES: 1. Dimensions are in millimeters. Dimensions in ( ) for Reference Only. 2. Dimensioning and tolerancing conform to AMSE Y14.5m-1994. 3. Unless otherwise specified, tolerance : Decimal ± 0.05 4. Dimension b applies to the metallized terminal and is measured between 0.15mm and 0.30mm from the terminal tip. 5. Tiebar shown (if present) is a non-functional feature. 6. The configuration of the pin #1 identifier is optional, but must be located within the zone indicated. The pin #1 identifier may be either a mold or mark feature. 26 FN6362.0 May 27, 2008