ICL3237E ® Data Sheet July 2004 ±15kV ESD Protected, 10nA SupplyCurrent, +3V to +5.5V, 250k/1Mbps, RS-232 Transmitters/Receivers FN6014.2 Features • ESD Protection For RS-232 I/O Pins to ±15kV (IEC61000) The Intersil ICL3237E contains 3.0V to 5.5V powered RS-232 transmitters/receivers which meet ElA/TIA-232 and V.28/V.24 specifications, even at VCC = 3.0V. Additionally, it provides ±15kV ESD protection (IEC61000-4-2 Air Gap and Human Body Model) on transmitter outputs and receiver inputs (RS-232 pins). Targeted applications are cell phones, PDAs, Palmtops, and notebook and laptop computers where the low operational, and even lower standby, power consumption is critical. Efficient on-chip charge pumps, coupled with the manual powerdown function, reduce the standby supply current to a 10nA trickle. Small footprint packaging, and the use of small, low value capacitors ensure board space savings as well. Data rates greater than 1Mbps (MBAUD = VCC) are guaranteed at worst case load conditions. The ICL3237E is fully compatible with 3.3V only systems, mixed 3.3V and 5.0V systems, and 5.0V only systems. The ICL3237E is a 5 driver, 3 receiver device that also includes a noninverting always-active receiver for “wake-up” capability. Table 1 summarizes the features of the device represented by this data sheet, while Application Note AN9863 summarizes the features of each device comprising the ICL32XX 3V family. • Pin Compatible Replacement for MAX3237E • Pin Selectable, Guaranteed Data Rate . . 250kbps/1Mbps • Meets EIA/TIA-232 and V.28/V.24 Specifications at 3V • RS-232 Compatible with VCC = 2.7V • Latch-Up Free • On-Chip Voltage Converters Require Only Four External Capacitors • Manual Powerdown Feature • Flow Through Pinout • Rx and Tx Hysteresis For Improved Noise Immunity • Rx Active in Powerdown; Separate Rx Enable Pin • Guaranteed Minimum Slew Rate . . . . . . . 6V/µs or 24V/µs • Wide Power Supply Range. . . . . . . . Single +3V to +5.5V • Low Supply Current in Powerdown State . . . . . . . . . .10nA • Pb-free available Applications • Any System Requiring RS-232 Communication Ports - Battery Powered, Hand-Held, and Portable Equipment - Laptop Computers, Notebooks, Palmtops - Modems, Printers and other Peripherals - Data Cradles and Cables - Cellular/Mobile Phone TABLE 1. SUMMARY OF FEATURES PART NUMBER ICL3237E NO. OF NO. OF Tx. Rx. 5 3 NO. OF MONITOR Rx. (ROUTB) (NOTE 1) DATA RATE (kbps) Rx. ENABLE FUNCTION? READY OUTPUT? MANUAL POWERDOWN? AUTOMATIC POWERDOWN FUNCTION? 1 250/1000 YES NO YES NO NOTE: 1. Data rate is selectable via the MBAUD pin. 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 321-724-7143 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2002-2004. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ICL3237E Pinout Ordering Information ICL3237E (SSOP) TOP VIEW C2+ 1 GND 2 C2- 3 V- 4 28 C1+ TEMP. PART NUMBER RANGE (oC) 27 V+ ICL3237ECA 0 to 70 28 Ld SSOP M28.209 26 VCC ICL3237ECAZ (See Note) 0 to 70 28 Ld SSOP (Pb-free) M28.209 25 C1- ICL3237EIA -40 to 85 28 Ld SSOP M28.209 ICL3237EIAZ (See Note) -40 to 85 28 Ld SSOP (Pb-free) M28.209 T1OUT 5 24 T1IN T2OUT 6 23 T2IN T3OUT 7 22 T3IN R1IN 8 21 R1OUT R2IN 9 20 R2OUT NOTE: Intersil Pb-free products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which is 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-020B. 18 R3OUT R3IN 11 17 T5IN T5OUT 12 EN 13 16 R1OUTB SHDN 14 15 MBAUD PKG. DWG. # *Add “-T” suffix to part number for tape and reel packaging. 19 T4IN T4OUT 10 PACKAGE Pin Descriptions PIN VCC FUNCTION System power supply input (3.0V to 5.5V). V+ Internally generated positive transmitter supply (+5.5V). V- Internally generated negative transmitter supply (-5.5V). GND Ground connection. C1+ External capacitor (voltage doubler) is connected to this lead. C1- External capacitor (voltage doubler) is connected to this lead. C2+ External capacitor (voltage inverter) is connected to this lead. C2- External capacitor (voltage inverter) is connected to this lead. TIN TTL/CMOS compatible transmitter Inputs (Note 2). TOUT RIN ROUT ROUTB EN SHDN MBAUD ±15kV ESD Protected, RS-232 level (nominally ±5.5V) transmitter outputs. ±15kV ESD Protected, RS-232 compatible receiver inputs. TTL/CMOS level receiver outputs. TTL/CMOS level, noninverting, always enabled receiver output. Active low receiver enable control; doesn’t disable ROUTB output (Note 2). Active low input to shut down transmitters and on-board power supply, to place device in low power mode (Note 2). Input low selects 250kbps data rate, and input high selects 1Mbps data rate (Note 2). NOTE: 2. These input pins incorporate positive feedback resistors. Once the input is driven to a valid logic level, the feedback resistor maintains that logic level until VCC is removed. 2 ICL3237E Typical Operating Circuit ICL3237E NOTE 4 + 0.1µF 28 C1 0.1µF + C2 0.1µF + + C3 (OPTIONAL CONNECTION, NOTE 3) +3.3V 25 1 3 C1+ 26 27 VCC C1C2+ V- C2T1 24 + V+ 4 NOTE 4 C4 0.1µF + 5 T1IN T1OUT T2 23 6 T2IN T2OUT T3 22 7 T3IN T3OUT T4 19 RS-232 LEVELS 10 T4IN T4OUT T5 17 12 T5IN TTL/CMOS LOGIC LEVELS C3 0.1µF T5OUT 16 R1OUTB 21 8 R1OUT R1IN 5kΩ R1 20 9 R2OUT R2IN 5kΩ R2 18 11 R3OUT R3IN 5kΩ R3 13 VCC RS-232 LEVELS EN 14 SHDN 15 TO CONTROL LOGIC MBAUD GND 2 NOTES: 3. THE NEGATIVE TERMINAL OF C3 CAN BE CONNECTED TO EITHER VCC OR GND. 4. FOR VCC = 3.15V (3.3V -5%), USE C1 - C4 = 0.1µF OR GREATER. FOR VCC = 3.0V (3.3V -10%), USE C1 - C4 = 0.22µF. 3 ICL3237E Absolute Maximum Ratings Thermal Information VCC to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V V+ to Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 7V V- to Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3V to -7V V+ to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14V Input Voltages TIN, EN, SHDN, MBAUD . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6V RIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±25V Output Voltages TOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±13.2V ROUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC +0.3V Short Circuit Duration TOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table Thermal Resistance (Typical, Note 5) θJA (oC/W) 28 Ld SSOP Package . . . . . . . . . . . . . . . . . . . . . . . 100 Moisture Sensitivity (see Technical Brief TB363) SSOP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Level 1 Maximum Junction Temperature (Plastic Package) . . . . . . . 150oC Maximum Storage Temperature Range . . . . . . . . . . -65oC to 150oC Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300oC (Lead Tips Only) Operating Conditions Temperature Range ICL3237EC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0oC to 70oC ICL3237EI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40oC to 85oC CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. NOTE: 5. θJA is measured with the component mounted on a low effective thermal conductivity test board in free air. See Tech Brief TB379 for details. Electrical Specifications Test Conditions: VCC = 3.15V to 5.5V, C1 - C4 = 0.1µF; VCC = 3V, C1 - C4 = 0.22µF, Unless Otherwise Specified. Typicals are at TA = 25oC PARAMETER TEST CONDITIONS TEMP (oC) MIN TYP MAX UNITS DC CHARACTERISTICS Supply Current, Powerdown Disabled All Outputs Unloaded, VCC = 3.15V, SHDN = VCC 25 - 0.3 1.0 mA Supply Current, Powerdown SHDN = GND 25 - 10 300 nA LOGIC AND TRANSMITTER INPUTS AND RECEIVER OUTPUTS Input Logic Threshold Low TIN, EN, SHDN, MBAUD Full - - 0.8 V Input Logic Threshold High TIN, EN, SHDN, MBAUD VCC = 3.3V Full 2.0 - - V VCC = 5.0V Full 2.4 - - V 25 - 0.5 - V Transmitter Input Hysteresis Input Leakage Current TIN, EN, SHDN, MBAUD (Note 7) Full - ±0.01 ±1.0 µA Output Leakage Current EN = VCC (Receivers Disabled) Full - ±0.05 ±10 µA Output Voltage Low IOUT = 1.6mA Full - - 0.4 V Output Voltage High IOUT = -1.0mA Full - V VCC -0.6 VCC -0.1 RECEIVER INPUTS Input Voltage Range Input Threshold Low Full -25 - 25 V VCC = 3.3V 25 0.6 1.2 - V VCC = 5.0V 25 0.8 1.5 - V VCC = 3.3V to 5.0V 25 - 1.6 2.4 V Input Hysteresis 25 - 0.5 - V Input Resistance 25 3 5 7 kΩ Full ±5.0 ±5.4 - V Input Threshold High TRANSMITTER OUTPUTS Output Voltage Swing All Transmitter Outputs Loaded with 3kΩ to Ground Output Resistance VCC = V+ = V- = 0V, Transmitter Output = ±2V Output Short-Circuit Current Output Leakage Current VOUT = ±12V, VCC = 0V or 3V to 5.5V, SHDN = GND 4 Full 300 10M - Ω Full - ±35 ±60 mA Full - - ±25 µA ICL3237E Electrical Specifications Test Conditions: VCC = 3.15V to 5.5V, C1 - C4 = 0.1µF; VCC = 3V, C1 - C4 = 0.22µF, Unless Otherwise Specified. Typicals are at TA = 25oC (Continued) PARAMETER TEMP (oC) MIN TYP MAX UNITS MBAUD = GND Full 250 700 - kbps MBAUD = VCC Full 1000 1700 - kbps MBAUD = VCC Full 1000 1100 - kbps tPHL 25 - 0.15 - µs tPLH 25 - 0.15 - µs TEST CONDITIONS TIMING CHARACTERISTICS Maximum Data Rate RL = 3kΩ, One CL = 1000pF Transmitter Switching VCC = 3V to 4.5V, CL = 250pF VCC = 4.5V to 5.5V, CL = 1000pF Receiver Propagation Delay Receiver Input to Receiver Output, CL = 150pF Receiver Output Enable Time Normal Operation 25 - 200 - ns Receiver Output Disable Time Normal Operation 25 - 200 - ns Transmitter Skew tPHL - tPLH, Note 6 25 - 100 25 - 25 Receiver Skew tPHL - tPLH, CL = 150pF 25 - 50 Transition Region Slew Rate CL = 150pF to 1000pF MBAUD = GND VCC = 3.3V, RL = 3kΩ to 7kΩ, MBAUD = VCC Measured From 3V to CL = 150pF to 2500pF MBAUD = GND -3V or -3V to 3V 25 6 17 30 V/µs 25 24 40 150 V/µs 25 4 12 30 V/µs Human Body Model 25 - ±15 - kV IEC61000-4-2 Air Gap Discharge 25 - ±15 - kV IEC61000-4-2 Contact Discharge 25 - ±8 - kV Human Body Model 25 - ±2.5 - kV MBAUD = GND MBAUD = VCC, VCC = 3.0V ns ns - ns ESD PERFORMANCE RS-232 Pins (TOUT, RIN) All Other Pins NOTES: 6. Skew is measured at the input switching points (1.4V). 7. These inputs utilize a positive feedback resistor. The input current is negligible when the input is at either supply rail. 5 ICL3237E Detailed Description The ICL3237E operates from a single +3V to +5.5V supply, guarantees a 1Mbps minimum data rate (MBAUD = VCC), requires only four small external 0.1µF (0.22µF for VCC = 3.0V) capacitors, features low power consumption, and meets all EIA/TIA-232 and V.28 specifications. The circuit is divided into three sections: The charge pump, the transmitters, and the receivers. Charge-Pump Intersil’s new ICL32XX family utilizes regulated on-chip dual charge pumps as voltage doublers, and voltage inverters to generate ±5.5V transmitter supplies from a VCC supply as low as 3.0V. This allows these devices to maintain RS-232 compliant output levels over the ±10% tolerance range of 3.3V powered systems. The efficient on-chip power supplies require only four small, external 0.1µF capacitors for the voltage doubler and inverter functions at VCC = 3.3V. See the “Capacitor Selection” section, and Table 3 for capacitor recommendations for other operating conditions. The charge pumps operate discontinuously (i.e., they turn off as soon as the V+ and V- supplies are pumped up to the nominal values), resulting in significant power savings. Transmitters The transmitters are proprietary, low dropout, inverting drivers that translate TTL/CMOS inputs to EIA/TIA-232 output levels. Coupled with the on-chip ±5.5V supplies, these transmitters deliver true RS-232 levels over a wide range of single supply system voltages. All transmitter outputs disable and assume a high impedance state when the device enters the powerdown mode (see Table 2). These outputs may be driven to ±12V when disabled. The ICL3237E guarantees a 1Mbps data rate (MBAUD = VCC) for full load conditions (3kΩ and 250pF), VCC ≥ 3.0V, with one transmitter operating at full speed. Under more typical conditions of VCC ≥ 3.3V, C1-4 = 0.1µF, RL = 3kΩ, and CL = 250pF, one transmitter easily operates at 1.7Mbps. Transmitter inputs incorporate an active positive feedback resistor that maintains the last driven input state in the absence of a forcing signal. Unused transmitter inputs may be left unconnected. Receivers The ICL3237E contains standard inverting receivers that tristate only when the EN control line is driven high. Additionally, it includes a noninverting (monitor) receiver (denoted by the ROUTB label) that is always active, regardless of the state of any control lines. All the receivers convert RS-232 signals to CMOS output levels and accept inputs up to ±25V while presenting the required 3kΩ to 7kΩ input impedance (see Figure 1) even if the power is off (VCC = 0V). The receivers’ Schmitt trigger input stage uses 6 hysteresis to increase noise immunity and decrease errors due to slow input signal transitions. Monitor receivers remain active even during manual powerdown and forced receiver disable, making them extremely useful for Ring Indicator monitoring. Standard receivers driving powered down peripherals must be disabled to prevent current flow through the peripheral’s protection diodes (see Figures 2 and 3). This renders them useless for wake up functions, but the corresponding monitor receiver can be dedicated to this task as shown in Figure 3. VCC RXOUT RXIN -25V ≤ VRIN ≤ +25V 5kΩ GND ≤ VROUT ≤ VCC GND FIGURE 1. INVERTING RECEIVER CONNECTIONS Powerdown Functionality This 3V device requires a nominal supply current of 0.3mA during normal operation (not in powerdown mode). This is considerably less than the 5mA to 11mA current required of 5V RS-232 devices. The already low current requirement drops significantly when the device enters powerdown mode. In powerdown, supply current drops to 10nA, because the on-chip charge pump turns off (V+ collapses to VCC, Vcollapses to GND), and the transmitter outputs tristate. This micro-power mode makes the ICL3237E ideal for battery powered and portable applications. Software Controlled (Manual) Powerdown On the ICL3237E, the powerdown control is via a simple shutdown (SHDN) pin. Driving this pin high enables normal operation, while driving it low forces the IC into it’s powerdown state. Connect SHDN to VCC if the powerdown function isn’t needed. Note that all the receiver outputs remain enabled during shutdown (see Table 2). For the lowest power consumption during powerdown, the receivers should also be disabled by driving the EN input high (see next section, and Figures 2 and 3). The time required to exit powerdown, and resume transmission is only 100µs. ICL3237E TABLE 2. POWERDOWN AND ENABLE LOGIC TRUTH TABLE SHDN INPUT EN INPUT TRANSMITTER OUTPUTS RECEIVER OUTPUTS ROUTB OUTPUT L L High-Z Active Active Manual Powerdown MODE OF OPERATION L H High-Z High-Z Active Manual Powerdown w/Rcvr. Disabled H L Active Active Active Normal Operation H H Active High-Z Active Normal Operation w/Rcvr. Disabled MegaBaud Selection VCC VCC In normal operating mode (MBAUD = GND), the ICL3237E transmitters guarantee a 250kbps data rate with worst-case loads of 3kΩ in parallel with 1000pF. This provides compatibility with PC-to-PC communication software, such as Laplink™. CURRENT FLOW VCC VOUT = VCC Rx For higher speed serial communications, the ICL3237E features MegaBaud operation. In MegaBaud operating mode (MBAUD = VCC), the ICL3237E transmitters guarantee a 1Mbps data rate with worst-case loads of 3kΩ in parallel with 250pF for 3.0V < VCC < 4.5V. For 5V ±10% operation, the ICL3237E transmitters guarantee a 1Mbps data rate with worst-case loads of 3kΩ in parallel with 1000pF. POWERED DOWN UART Tx SHDN = GND GND OLD RS-232 CHIP FIGURE 2. POWER DRAIN THROUGH POWERED DOWN PERIPHERAL The charge pumps require 0.1µF capacitors for 3.3V (5% tolerance) operation. For other supply voltages refer to Table 3 for capacitor values. Do not use values smaller than those listed in Table 3. Increasing the capacitor values (by a factor of 2) reduces ripple on the transmitter outputs and slightly reduces power consumption. C2, C3, and C4 can be increased without increasing C1’s value, however, do not increase C1 without also increasing C2, C3, and C4 to maintain the proper ratios (C1 to the other capacitors). VCC TRANSITION DETECTOR TO WAKE-UP LOGIC ICL3237E VCC R1OUTB RX POWERED DOWN UART VOUT = HI-Z R1OUT TX R1IN T1IN T1OUT SHDN = GND, EN = VCC FIGURE 3. DISABLED RECEIVERS PREVENT POWER DRAIN Receiver ENABLE Control This device also features an EN input to control the receiver outputs. Driving EN high disables all the inverting (standard) receiver outputs placing them in a high impedance state. This is useful to eliminate supply current, due to a receiver output forward biasing the protection diode, when driving the input of a powered down (VCC = GND) peripheral (see Figure 2). The enable input has no effect on transmitter nor monitor (ROUTB) outputs. 7 Capacitor Selection When using minimum required capacitor values, make sure that capacitor values do not degrade excessively with temperature. If in doubt, use capacitors with a larger nominal value. The capacitor’s equivalent series resistance (ESR) usually rises at low temperatures and it influences the amount of ripple on V+ and V-. TABLE 3. REQUIRED CAPACITOR VALUES VCC (V) C1 (µF) C2, C3, C4 (µF) 3.0 to 3.6 (3.3V ±10%) 0.22 0.22 3.15 to 3.6 (3.3V ±5%) 0.1 0.1 4.5 to 5.5 0.047 0.33 3.0 to 5.5 0.22 1.0 Power Supply Decoupling In most circumstances a 0.1µF bypass capacitor is adequate. In applications that are particularly sensitive to power supply noise, decouple VCC to ground with a capacitor of the same value as the charge-pump capacitor C1. Connect the bypass capacitor as close as possible to the IC. Laplink® is a registered trademark of Traveling Software. ICL3237E Operation Down to 2.7V VCC ICL3237E transmitter outputs meet RS-562 levels (±3.7V), at the full data rate, with VCC as low as 2.7V. RS-562 levels typically ensure inter operability with RS-232 devices. + C1+ VCC V+ C1 Transmitter Outputs when Exiting Powerdown C1- + C3 ICL3237E + Figure 4 shows the response of two transmitter outputs when exiting powerdown mode. As they activate, the two transmitter outputs properly go to opposite RS-232 levels, with no glitching, ringing, nor undesirable transients. Each transmitter is loaded with 3kΩ in parallel with 2500pF. Note that the transmitters enable only when the magnitude of the supplies exceed approximately 3V. V- C2+ C2 TIN TOUT RIN ROUT EN CL 5k SHDN MBAUD SHDN T1 C4 + C2- VCC 5V/DIV + 0.1µF GND or VCC FIGURE 5. TRANSMITTER LOOPBACK TEST CIRCUIT 5V/DIV. MBAUD = GND T1IN 2V/DIV T2 T1OUT VCC = +3.3V C1 - C4 = 0.1µF TIME (20µs/DIV.) FIGURE 4. TRANSMITTER OUTPUTS WHEN EXITING POWERDOWN R1OUT VCC = +3.3V C1 - C4 = 0.1µF High Data Rates The ICL3237E maintains the RS-232 ±5V minimum transmitter output voltages even at high data rates. Figure 5 details a transmitter loopback test circuit, and Figure 6 illustrates the standard speed loopback test result for a single transmitter driving 1000pF and an RS-232 load at 250kbps. Figure 7 shows the MegaBaud loopback results for a single transmitter driving 250pF and an RS-232 load at 1Mbps. The static transmitters were also loaded with an RS-232 receiver. 2µs/DIV. FIGURE 6. LOOPBACK TEST AT 250kbps (CL = 1000pF) 5V/DIV. MBAUD = VCC T1IN T1OUT R1OUT VCC = +3.3V C1 - C4 = 0.1µF 0.5µs/DIV. FIGURE 7. LOOPBACK TEST AT 1Mbps (CL = 250pF) 8 ICL3237E Interconnection with 3V and 5V Logic Human Body Model (HBM) Testing The ICL3237E directly interfaces with 5V CMOS and TTL logic families. Nevertheless, with the ICL32XX at 3.3V, and the logic supply at 5V, AC, HC, and CD4000 outputs can drive ICL32XX inputs, but ICL32XX outputs do not reach the minimum VIH for these logic families. See Table 4 for more information. As the name implies, this test method emulates the ESD event delivered to an IC during human handling. The tester delivers the charge through a 1.5kΩ current limiting resistor, making the test less severe than the IEC61000 test which utilizes a 330Ω limiting resistor. The HBM method determines an ICs ability to withstand the ESD transients typically present during handling and manufacturing. Due to the random nature of these events, each pin is tested with respect to all other pins. The RS-232 pins on “E” family devices can withstand HBM ESD events to ±15kV. TABLE 4. LOGIC FAMILY COMPATIBILITY WITH VARIOUS SUPPLY VOLTAGES VCC SYSTEM POWER-SUPPLY SUPPLY VOLTAGE VOLTAGE (V) (V) 3.3 3.3 5 5 5 3.3 IEC61000-4-2 Testing COMPATIBILITY Compatible with all CMOS families. Compatible with all TTL and CMOS logic families. Compatible with ACT and HCT CMOS, and with TTL. ICL32XX outputs are incompatible with AC, HC, and CD4000 CMOS inputs. ±15kV ESD Protection All pins on ICL32XX devices include ESD protection structures, but the ICL32XXE family incorporates advanced structures which allow the RS-232 pins (transmitter outputs and receiver inputs) to survive ESD events up to ±15kV. The RS-232 pins are particularly vulnerable to ESD damage because they typically connect to an exposed port on the exterior of the finished product. Simply touching the port pins, or connecting a cable, can cause an ESD event that might destroy unprotected ICs. These new ESD structures protect the device whether or not it is powered up, protect without allowing any latchup mechanism to activate, and don’t interfere with RS-232 signals as large as ±25V. 9 The IEC61000 test method applies to finished equipment, rather than to an individual IC. Therefore, the pins most likely to suffer an ESD event are those that are exposed to the outside world (the RS-232 pins in this case), and the IC is tested in its typical application configuration (power applied) rather than testing each pin-to-pin combination. The lower current limiting resistor coupled with the larger charge storage capacitor yields a test that is much more severe than the HBM test. The extra ESD protection built into this device’s RS-232 pins allows the design of equipment meeting level 4 criteria without the need for additional board level protection on the RS-232 port. AIR-GAP DISCHARGE TEST METHOD For this test method, a charged probe tip moves toward the IC pin until the voltage arcs to it. The current waveform delivered to the IC pin depends on approach speed, humidity, temperature, etc., so it is difficult to obtain repeatable results.The “E” device RS-232 pins withstand ±15kV air-gap discharges. CONTACT DISCHARGE TEST METHOD During the contact discharge test, the probe contacts the tested pin before the probe tip is energized, thereby eliminating the variables associated with the air-gap discharge. The result is a more repeatable and predictable test, but equipment limits prevent testing devices at voltages higher than ±8kV. All “E” family devices survive ±8kV contact discharges on the RS-232 pins. ICL3237E Typical Performance Curves VCC = 3.3V, TA = 25oC 6 TRANSMITTER OUTPUT VOLTAGE (V) TRANSMITTER OUTPUT VOLTAGE (V) 6 VOUT+ 4 2 1 TRANSMITTER AT 250kbps OTHER TRANSMITTERS AT 30kbps 0 MBAUD = GND -2 VOUT - -4 -6 0 1000 2000 3000 4000 VOUT+ 4 2 1 TRANSMITTER AT 1Mbps OTHER TRANSMITTERS AT 30kbps 0 MBAUD = VCC -2 VOUT -4 -6 5000 0 1000 2000 LOAD CAPACITANCE (pF) 3000 4000 FIGURE 8. LOW SPEED TRANSMITTER OUTPUT VOLTAGE vs LOAD CAPACITANCE FIGURE 9. HIGH SPEED TRANSMITTER OUTPUT VOLTAGE vs LOAD CAPACITANCE 25 90 MBAUD = GND MBAUD = VCC 70 20 +SLEW SLEW RATE (V/µs) SLEW RATE (V/µs) 5000 LOAD CAPACITANCE (pF) 15 -SLEW 10 +SLEW 50 30 -SLEW -SLEW 10 5 0 1000 2000 3000 4000 0 5000 0 1000 LOAD CAPACITANCE (pF) 3000 4000 5000 LOAD CAPACITANCE (pF) FIGURE 10. LOW SPEED SLEW RATE vs LOAD CAPACITANCE FIGURE 11. HIGH SPEED SLEW RATE vs LOAD CAPACITANCE 90 55 MBAUD = VCC MBAUD = GND 1Mbps 80 45 SUPPLY CURRENT (mA) 50 SUPPLY CURRENT (mA) 2000 250kbps 40 120kbps 35 30 25 20kbps 70 60 50 250kbps 40 120kbps 30 20 20 0 1000 2000 3000 4000 5000 LOAD CAPACITANCE (pF) FIGURE 12. LOW SPEED SUPPLY CURRENT vs LOAD CAPACITANCE WHEN TRANSMITTING DATA 10 0 1000 2000 3000 4000 5000 LOAD CAPACITANCE (pF) FIGURE 13. HIGH SPEED SUPPLY CURRENT vs LOAD CAPACITANCE WHEN TRANSMITTING DATA ICL3237E Typical Performance Curves VCC = 3.3V, TA = 25oC (Continued) 3.5 NO LOAD ALL OUTPUTS STATIC SUPPLY CURRENT (mA) 3.0 2.5 2.0 1.5 1.0 0.5 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 SUPPLY VOLTAGE (V) FIGURE 14. SUPPLY CURRENT vs SUPPLY VOLTAGE Die Characteristics SUBSTRATE POTENTIAL (POWERED UP): GND TRANSISTOR COUNT: 619 PROCES Si Gate CMOS 11 6.0 ICL3237E 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 -B1 2 SYMBOL GAUGE PLANE 3 L 0.25 0.010 SEATING PLANE -A- A D -C- µα e B C 0.10(0.004) 0.25(0.010) M C A M B S MIN MAX NOTES A - 0.078 - 2.00 - 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 0.026 BSC 0.65 BSC - H 0.292 0.322 7.40 8.20 - L 0.022 0.037 0.55 0.95 6 8o 0o N α NOTES: MAX A1 e A2 A1 MILLIMETERS MIN 28 0o 28 7 8o 8. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of Publication Number 95. Rev. 1 3/95 9. Dimensioning and tolerancing per ANSI Y14.5M-1982. 10. 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. 11. Dimension “E” does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.20mm (0.0078 inch) per side. 12. The chamfer on the body is optional. If it is not present, a visual index feature must be located within the crosshatched area. 13. “L” is the length of terminal for soldering to a substrate. 14. “N” is the number of terminal positions. 15. Terminal numbers are shown for reference only. 16. 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. 17. 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 12