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ICL3221 thru ICL3243
TM
Data Sheet
May 2000
File Number
4805.2
1 Microamp Supply-Current, +3V to +5.5V, 250kbps, RS-232 Transmitters/Receivers
The Intersil ICL32XX devices are 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. Targeted applications are 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 manual and automatic powerdown functions (except for the ICL3232), reduce the standby supply current to a 1A trickle. Small footprint packaging, and the use of small, low value capacitors ensure board space savings as well. Data rates greater than 250kbps are guaranteed at worst case load conditions. This family is fully compatible with 3.3V only systems, mixed 3.3V and 5.0V systems, and 5.0V only systems. The ICL324X are 3 driver, 5 receiver devices that provide a complete serial port suitable for laptop or notebook computers. Both devices also include noninverting alwaysactive receivers for "wake-up" capability. The ICL3221, ICL3223 and ICL3243, feature an automatic powerdown function which powers down the on-chip powersupply and driver circuits. This occurs when an attached peripheral device is shut off or the RS-232 cable is removed, conserving system power automatically without changes to the hardware or operating system. These devices power up again when a valid RS-232 voltage is applied to any receiver input. Table 1 summarizes the features of the devices represented by this data sheet, while Application Note AN9863 summarizes the features of each device comprising the ICL32XX 3V family.
Features
* Drop in Replacements for MAX3221, MAX3222, MAX3223, MAX3232, MAX3241, MAX3243, SP3243 * ICL3222 is Low Power, Pin Compatible Upgrade for 5V MAX242, and SP312A * ICL3232 is Low Power Upgrade for HIN232/ICL232 and Pin Compatible Competitor Devices * Meets EIA/TIA-232 and V.28/V.24 Specifications at 3V * Latch-Up Free * On-Chip Voltage Converters Require Only Four External 0.1F Capacitors * Manual and Automatic Powerdown Features (Except ICL3232) * Guaranteed Mouse Driveability * Receiver Hysteresis For Improved Noise Immunity * Guaranteed Minimum Data Rate . . . . . . . . . . . . 250kbps * Guaranteed Minimum Slew Rate . . . . . . . . . . . . . . . 6V/s * Wide Power Supply Range. . . . . . . . Single +3V to +5.5V * Low Supply Current in Powerdown State . . . . . . . . . . 1A
Applications
* Any System Requiring RS-232 Communication Ports - Battery Powered, Hand-Held, and Portable Equipment - Laptop Computers, Notebooks, Palmtops - Modems, Printers and other Peripherals - Digital Cameras - Cellular/Mobile Phones
TABLE 1. SUMMARY OF FEATURES PART NUMBER ICL3221 ICL3222 ICL3223 ICL3232 ICL3241 ICL3243 NO. OF NO. OF Tx. Rx. 1 2 2 2 3 3 1 2 2 2 5 5 NO. OF MONITOR Rx. (ROUTB) 0 0 0 0 2 1 DATA RATE (kbps) 250 250 250 250 250 250 Rx. ENABLE FUNCTION? YES YES YES NO YES NO READY OUTPUT? NO NO NO NO NO NO MANUAL POWERDOWN? YES YES YES NO YES YES AUTOMATIC POWERDOWN FUNCTION? YES NO YES NO NO YES
3-1
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 trademark of Intersil Corporation. | Copyright (c) Intersil Corporation 2000
ICL3221 thru ICL3243 Ordering Information
(NOTE 1) PART NO. ICL3221CA ICL3221CV ICL3222CA ICL3222CB ICL3222CP ICL3222CV ICL3223CA ICL3223CP ICL3223CV ICL3232CA ICL3232CB ICL3232CP ICL3232CV ICL3241CA ICL3241CB ICL3241CV ICL3243CA ICL3243CB ICL3243CV NOTE: 1. Most surface mount devices are available on tape and reel; add "-T" to suffix. TEMP. RANGE (oC) 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 0 to 70 PACKAGE 16 Ld SSOP 16 Ld TSSOP 20 Ld SSOP 18 Ld SOIC 18 Ld PDIP 20 Ld TSSOP 20 Ld SSOP 20 Ld PDIP 20 Ld TSSOP 16 Ld SSOP 16 Ld SOIC 16 Ld PDIP 16 Ld TSSOP 28 Ld SSOP 28 Ld SOIC 28 Ld TSSOP 28 Ld SSOP 28 Ld SOIC 28 Ld TSSOP PKG. NO. M16.209 M16.173 M20.209 M18.3 E18.3 M20.173 M20.209 E20.3 M20.173 M16.209 M16.3 E16.3 M16.173 M28.209 M28.3 M28.173 M28.209 M28.3 M28.173
Pinouts
ICL3221 (SSOP, TSSOP) TOP VIEW ICL3222 (PDIP, SOIC) TOP VIEW
EN 1 C1+ 2 V+ 3 18 SHDN 17 VCC 16 GND 15 T1OUT 14 R1IN 13 R1OUT 12 T1IN 11 T2IN 10 R2OUT
EN 1 C1+ 2 V+ 3
16 FORCEOFF 15 VCC 14 GND 13 T1OUT 12 FORCEON 11 T1IN 10 INVALID 9 R1OUT
C1- 4 C2+ 5 C2- 6 V- 7 R1IN 8
C1- 4 C2+ 5 C2- 6 V- 7 T2OUT 8 R2IN 9
3-2
ICL3221 thru ICL3243 Pinouts
(Continued) ICL3222 (SSOP, TSSOP) TOP VIEW ICL3223 (PDIP, SSOP, TSSOP) TOP VIEW
EN 1 C1+ 2 V+ 3
20 SHDN 19 VCC 18 GND 17 T1OUT 16 R1IN 15 R1OUT 14 NC 13 T1IN 12 T2IN 11 NC
EN 1 C1+ 2 V+ 3
20 FORCEOFF 19 VCC 18 GND 17 T1OUT 16 R1IN 15 R1OUT 14 FORCEON 13 T1IN 12 T2IN 11 INVALID
C1- 4 C2+ 5 C2- 6 V- 7 T2OUT 8 R2IN 9 R2OUT 10
C1- 4 C2+ 5 C2- 6 V- 7 T2OUT 8 R2IN 9 R2OUT 10
ICL3232 (PDIP, SOIC, SSOP, TSSOP) TOP VIEW
C1+ 1 V+ 2 C13 16 VCC 15 GND 14 T1OUT 13 R1IN 12 R1OUT 11 T1IN 10 T2IN 9 R2OUT
ICL3241 (SOIC, SSOP, TSSOP) TOP VIEW
C2+ 1 C2- 2 V3 28 C1+ 27 V+ 26 VCC 25 GND 24 C123 EN 22 SHDN 21 R1OUTB 20 R2OUTB 19 R1OUT 18 R2OUT 17 R3OUT 16 R4OUT 15 R5OUT
C2+ 4 C2- 5 V- 6 T2OUT 7 R2IN 8
R1IN 4 R2IN 5 R3IN 6 R4IN 7 R5IN 8 T1OUT 9 T2OUT 10 T3OUT 11 T3IN 12 T2IN 13 T1IN 14
ICL3243 (SOIC, SSOP, TSSOP) TOP VIEW
C2+ 1 C2- 2 V3 28 C1+ 27 V+ 26 VCC 25 GND 24 C123 FORCEON 22 FORCEOFF 21 INVALID 20 R2OUTB 19 R1OUT 18 R2OUT 17 R3OUT 16 R4OUT 15 R5OUT
R1IN 4 R2IN 5 R3IN 6 R4IN 7 R5IN 8 T1OUT 9 T2OUT 10 T3OUT 11 T3IN 12 T2IN 13 T1IN 14
3-3
ICL3221 thru ICL3243 Pin Descriptions
PIN VCC V+ VGND C1+ C1C2+ C2TIN TOUT RIN ROUT ROUTB INVALID EN SHDN System power supply input (3.0V to 5.5V). Internally generated positive transmitter supply (+5.5V). Internally generated negative transmitter supply (-5.5V). Ground connection. External capacitor (voltage doubler) is connected to this lead. External capacitor (voltage doubler) is connected to this lead. External capacitor (voltage inverter) is connected to this lead. External capacitor (voltage inverter) is connected to this lead. TTL/CMOS compatible transmitter Inputs. RS-232 level (nominally 5.5V) transmitter outputs. RS-232 compatible receiver inputs. TTL/CMOS level receiver outputs. TTL/CMOS level, noninverting, always enabled receiver outputs. Active low output that indicates if no valid RS-232 levels are present on any receiver input. Active low receiver enable control; doesn't disable ROUTB outputs. Active low input to shut down transmitters and on-board power supply, to place device in low power mode. FUNCTION
FORCEOFF Active low to shut down transmitters and on-chip power supply. This overrides any automatic circuitry and FORCEON (see Table 2). FORCEON Active high input to override automatic powerdown circuitry thereby keeping transmitters active. (FORCEOFF must be high).
Typical Operating Circuits
ICL3221
+3.3V + 0.1F 15 VCC 3 V+ V- 7 T1 13 + C3 0.1F C4 + 0.1F T1OUT RS-232 LEVELS
C1 0.1F C2 0.1F
2 + C1+ 4 C15 + C2+ 6 C211
T1IN TTL/CMOS LOGIC LEVELS R1OUT
9 R1 1 EN 5k
8
R1IN
16 FORCEOFF 12 FORCEON GND 14 INVALID 10
VCC TO POWER CONTROL LOGIC
3-4
ICL3221 thru ICL3243 Typical Operating Circuits
(Continued) ICL3222
+3.3V + 0.1F 2 + 4 5 + 6 12 C1+ C1C2+ C2T1 T2 V15 8 T2OUT 14 R1 10 R2OUT 1 EN R2 5k 5k 9 R2IN RS-232 LEVELS 17 VCC 3 V+ 7 + + C3 0.1F C4 0.1F
C1 0.1F C2 0.1F
T1IN T2IN TTL/CMOS LOGIC LEVELS R1OUT
T1OUT
11
13
R1IN
SHDN GND 16
18
VCC
ICL3223
+3.3V + 0.1F 2 + 4 5 + 6 13 C1+ C1C2+ C2T1 T2
19 VCC V+ 3 + C3 0.1F C4 0.1F + T1OUT T2OUT RS-232 LEVELS
C1 0.1F C2 0.1F
V- 7 17
T1IN T2IN TTL/CMOS LOGIC LEVELS R1OUT
12
8
15 R1 5k
16
R1IN
R2OUT
10 1 EN R2 5k
9
R2IN
FORCEOFF 14 FORCEON GND 18 INVALID
20 11
VCC TO POWER CONTROL LOGIC
3-5
ICL3221 thru ICL3243 Typical Operating Circuits
(Continued) ICL3232
+3.3V + 0.1F 1 + + 5 11 3 4 C1+ C1C2+ C2T1 T2 V-
16 VCC V+ 2 + C3 0.1F C4 0.1F + T1OUT T2OUT 13 R1 5k 8 R2 GND 15 5k R2IN RS-232 LEVELS
C1 0.1F C2 0.1F
6
T1IN T2IN TTL/CMOS LOGIC LEVELS R1OUT
14 7
10
12
R1IN
9 R2OUT
3-6
ICL3221 thru ICL3243 Typical Operating Circuits
(Continued) ICL3241
+3.3V + 0.1F
26 VCC V+ 27 + C3 0.1F C4 0.1F + T1OUT T2OUT RS-232 LEVELS
C1 0.1F C2 0.1F
28 C1+ + 24 C11 C2+ + 2 C214 13
VT1 T2 T3
3
T1IN T2IN
9 10 11
12 T3IN 21 R1OUTB 20 R2OUTB 19 TTL/CMOS LOGIC LEVELS R1OUT
T3OUT
4 R1IN R1 5k 5 R2IN R2 5k 6 R3IN R3 5k 7 R4IN R4 5k 8 R5IN R5 5k RS-232 LEVELS
18 R2OUT
17 R3OUT
16 R4OUT
15 R5OUT 23 EN
VCC
22 SHDN GND 25
3-7
ICL3221 thru ICL3243 Typical Operating Circuits
(Continued) ICL3243
+3.3V + 0.1F 28 + 24 C1+
26 VCC 27 V+ 3 + C3 0.1F
C1 0.1F C2 0.1F
C11 C2+ + 2 C214 T1
V-
C4 0.1F + T1OUT
9
T1IN 13 T2IN 12 T3IN 20 R2OUTB TTL/CMOS LOGIC LEVELS 19 R1OUT R1 18 R2OUT R2 17 R3OUT R3 16 R4OUT R4 15 R5OUT 23 R5 FORCEON VCC TO POWER CONTROL LOGIC 22 FORCEOFF 21 INVALID GND 25 5k 5k 8 5k 7 5k 6 5k 5 4 T3 11 T2 10
T2OUT
RS-232 LEVELS
T3OUT
R1IN
R2IN
R3IN
RS-232 LEVELS
R4IN
R5IN
3-8
ICL3221 thru ICL3243
Absolute Maximum Ratings
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, FORCEOFF, FORCEON, EN, SHDN . . . . . . . . . -0.3V to 6V RIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25V Output Voltages TOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2V ROUT, INVALID. . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC +0.3V Short Circuit Duration TOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . See Specification Table
Thermal Information
Thermal Resistance (Typical, Note 2) JA (oC/W) 16 Ld PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . 90 18 Ld PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . 80 20 Ld PDIP Package . . . . . . . . . . . . . . . . . . . . . . . . 77 16 Ld SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . 100 18 Ld SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . 75 28 Ld SOIC Package . . . . . . . . . . . . . . . . . . . . . . . . 75 16 Ld SSOP Package . . . . . . . . . . . . . . . . . . . . . . . 135 20 Ld SSOP Package . . . . . . . . . . . . . . . . . . . . . . . 122 16 Ld TSSOP Package . . . . . . . . . . . . . . . . . . . . . . 145 20 Ld TSSOP Package . . . . . . . . . . . . . . . . . . . . . . 140 28 Ld SSOP and TSSOP Packages . . . . . . . . . . . . 100 Moisture Sensitivity (see Technical Brief TB363) All Packages Not Listed Below. . . . . . . . . . . . . . . . . . . . . . Level 1 20 Ld TSSOP and 16 Ld SSOP and TSSOP Packages . . Level 2 Maximum Junction Temperature (Plastic Package) . . . . . . . 150oC Maximum Storage Temperature Range . . . . . . . . . . -65oC to 150oC Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300oC (SOIC, SSOP, TSSOP - Lead Tips Only)
Operating Conditions
Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . 0oC to 70oC
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: 2. JA is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications
Test Conditions: VCC = 3V to 5.5V, C1 - C4 = 0.1F; Unless Otherwise Specified. Typicals are at TA = 25oC TEST CONDITIONS TEMP (oC) MIN TYP MAX UNITS A A mA mA
PARAMETER DC CHARACTERISTICS Supply Current, Automatic Powerdown Supply Current, Powerdown Supply Current, Automatic Powerdown Disabled
All RIN Open, FORCEON = GND, FORCEOFF = VCC (ICL3221, ICL3223, ICL3243 Only) FORCEOFF = SHDN = GND (Except ICL3232) All Outputs Unloaded, FORCEON = FORCEOFF = SHDN = VCC VCC = 3.3V, ICL3221-32 VCC = 3.0V, ICL3241-43
25 25 25 25
-
1.0 1.0 0.3 0.3
10 10 1.0 1.0
LOGIC AND TRANSMITTER INPUTS AND RECEIVER OUTPUTS Input Logic Threshold Low Input Logic Threshold High TIN, FORCEON, FORCEOFF, EN, SHDN TIN, FORCEON, FORCEOFF, EN, SHDN VCC = 3.3V VCC = 5.0V Full Full Full Full Full Full Full 2.0 2.4 0.01 0.05 0.8 1.0 10 0.4 V V V A A V V
Input Leakage Current Output Leakage Current (Except ICL3232) Output Voltage Low Output Voltage High
TIN, FORCEON, FORCEOFF, EN, SHDN FORCEOFF = GND or EN = VCC IOUT = 1.6mA IOUT = -1.0mA ICL32XX Powers Up (See Figure 6) ICL32XX Powers Down (See Figure 6) IOUT = 1.6mA IOUT = -1.0mA
VCC -0.6 VCC -0.1 -2.7 -0.3 VCC-0.6 100
AUTOMATIC POWERDOWN (ICL3221, ICL3223, ICL3243 Only, FORCEON = GND, FORCEOFF = VCC) Receiver Input Thresholds to Enable Transmitters Receiver Input Thresholds to Disable Transmitters INVALID Output Voltage Low INVALID Output Voltage High Receiver Threshold to Transmitters Enabled Delay (tWU) Full Full Full Full 25 2.7 0.3 0.4 V V V V s
3-9
ICL3221 thru ICL3243
Electrical Specifications
Test Conditions: VCC = 3V to 5.5V, C1 - C4 = 0.1F; Unless Otherwise Specified. Typicals are at TA = 25oC (Continued) TEST CONDITIONS TEMP (oC) 25 MIN TYP 1 MAX UNITS s
PARAMETER Receiver Positive or Negative Threshold to INVALID High Delay (tINVH) Receiver Positive or Negative Threshold to INVALID Low Delay (tINVL) RECEIVER INPUTS Input Voltage Range Input Threshold Low VCC = 3.3V VCC = 5.0V Input Threshold High VCC = 3.3V VCC = 5.0V Input Hysteresis Input Resistance TRANSMITTER OUTPUTS Output Voltage Swing Output Resistance Output Short-Circuit Current Output Leakage Current (Except ICL3232)
25
-
30
-
s
Full 25 25 25 25 25 25
-25 0.6 0.8 3 5.0 300 -
1.2 1.5 1.5 1.8 0.3 5 5.4 10M 35 -
25 2.4 2.4 7
V V V V V V k
All Transmitter Outputs Loaded with 3k to Ground VCC = V+ = V- = 0V, Transmitter Output = 2V VOUT = 12V, VCC = 0V or 3V to 5.5V Automatic Powerdown or FORCEOFF = SHDN = GND
Full Full Full Full
60 25
V mA A
MOUSE DRIVEABILITY (ICL324X Only) Transmitter Output Voltage (See Figure 9) TIMING CHARACTERISTICS Maximum Data Rate (Note 3) Receiver Propagation Delay RL = 3k, CL = 1000pF, One Transmitter Switching Receiver Input to Receiver Output, CL = 150pF tPHL tPLH Full 25 25 25 25 Full Full CL = 200pF to 2500pF CL = 200pF to 1000pF 25 25 120 4 6 500 0.3 0.3 200 200 200 100 8.0 1000 500 30 30 kbps s s ns ns ns ns V/s V/s T1IN = T2IN = GND, T3IN = VCC, T3OUT Loaded with 3k to GND, T1OUT and T2OUT Loaded with 2.5mA Each Full 5 V
Receiver Output Enable Time Receiver Output Disable Time Transmitter Skew Receiver Skew Transition Region Slew Rate
Normal Operation (Except ICL3232) Normal Operation (Except ICL3232) tPHL - tPLH tPHL - tPLH VCC = 3.3V, RL = 3k to 7k, Measured From 3V to -3V or -3V to 3V
ESD PERFORMANCE RS-232 Pins (TOUT, RIN) Human Body Model IEC1000-4-2 Contact Discharge IEC1000-4-2 Air Gap Discharge ICL3221 - ICL3243 ICL3221 - ICL3243 ICL3221 - ICL3232 ICL3241 - ICL3243 All Other Pins NOTE: 3. All the ICL32XX devices are guaranteed to operate at a minimum data rate of 250kbps. The specification table lists a minimum of 120kbps to maintain complete compatibility with competitor data sheets. Human Body Model ICL3221 - ICL3243 25 25 25 25 25 >8 8 8 6 2.5 kV kV kV kV kV
3-10
ICL3221 thru ICL3243 Detailed Description
ICL32XX interface ICs operate from a single +3V to +5.5V supply, guarantee a 250kbps minimum data rate, require only four small external 0.1F capacitors, feature low power consumption, and meet all ElA RS-232C and V.28 specifications. The circuit is divided into three sections: The charge pump, the transmitters, and the receivers. The ICL3221/22/23/41 inverting receivers disable only when EN is driven high. ICL3243 receivers disable during forced (manual) powerdown, but not during automatic powerdown (see Table 2). ICL324X 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 RXIN -25V VRIN +25V GND 5k RXOUT GND VROUT VCC
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 0.1F 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.
FIGURE 1. INVERTING RECEIVER CONNECTIONS
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. Except for the ICL3232, 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. All devices guarantee a 250kbps data rate for full load conditions (3k and 1000pF), VCC 3.0V, with one transmitter operating at full speed. Under more typical conditions of VCC 3.3V, RL = 3k, and CL = 250pF, one transmitter easily operates at 900kbps. Transmitter inputs float if left unconnected, and may cause ICC increases. Connect unused inputs to GND for the best performance.
Powerdown Functionality (Except ICL3232)
This 3V family of RS-232 interface devices 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 1A, because the on-chip charge pump turns off (V+ collapses to VCC, V- collapses to GND), and the transmitter outputs tristate. Inverting receiver outputs may or may not disable in powerdown; refer to Table 2 for details. This micro-power mode makes these devices ideal for battery powered and portable applications.
Software Controlled (Manual) Powerdown
Most devices in the ICL32XX family provide pins that allow the user to force the IC into the low power, standby state. On the ICL3222 and ICL3241, 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 ICL3221, ICL3223, and ICL3243 utilize a two pin approach where the FORCEON and FORCEOFF inputs determine the IC's mode. For always enabled operation, FORCEON and FORCEOFF are both strapped high. To switch between active and powerdown modes, under logic or software control, only the FORCEOFF input need be driven.
Receivers
All the ICL32XX devices contain standard inverting receivers that tristate (except for the ICL3232) via the EN or FORCEOFF control lines. Additionally, the two ICL324X products include noninverting (monitor) receivers (denoted by the ROUTB label) that are 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 3k to 7k input impedance (see Figure 1) even if the power is off (VCC = 0V). The receivers' Schmitt trigger input stage uses hysteresis to increase noise immunity and decrease errors due to slow input signal transitions. 3-11
ICL3221 thru ICL3243
The FORCEON state isn't critical, as FORCEOFF dominates over FORCEON. Nevertheless, if strictly manual control over powerdown is desired, the user must strap FORCEON high to disable the automatic powerdown circuitry. Inverting (standard) receiver outputs also disable when the device is in powerdown, thereby eliminating the possible current path through a shutdown peripheral's input protection diode (see Figures 2 and 3). The INVALID output always indicates whether or not a valid RS-232 signal is present at any of the receiver inputs (see Table 2), giving the user an easy way to determine when the interface block should power down. In the case of a disconnected interface cable where all the receiver inputs are floating (but pulled to GND by the internal receiver pull down resistors), the INVALID logic detects the invalid levels and drives the output low. The power management logic then uses this indicator to power down the interface block. Reconnecting the cable restores valid levels at the receiver inputs, INVALID switches high, and the power management logic wakes up the interface block. INVALID can also be used to indicate the DTR or RING INDICATOR signal, as long as the other receiver inputs are floating, or driven to GND (as in the case of a powered down driver). Connecting FORCEOFF and FORCEON together disables the automatic powerdown feature, enabling them to function as a manual SHUTDOWN input (see Figure 4).
TABLE 2. POWERDOWN AND ENABLE LOGIC TRUTH TABLE RS-232 SIGNAL PRESENT AT RECEIVER INPUT?
FORCEOFF (NOTE 4) OR SHDN FORCEON EN TRANSMITTER RECEIVER ROUTB INVALID INPUT INPUT INPUT OUTPUTS OUTPUTS OUTPUTS OUTPUT
MODE OF OPERATION
ICL3222, ICL3241 N.A. N.A. N.A. N.A. ICL3221, ICL3223 NO NO YES YES NO NO YES YES NO NO ICL3243 NO YES NO YES NO NOTE: 4. Applies only to the ICL3241 and ICL3243. H H H L L H L L X X N.A. N.A. N.A. N.A. N.A. Active Active High-Z High-Z High-Z Active Active Active High-Z High-Z Active Active Active Active Active L H L H L Normal Operation (Auto Powerdown Disabled) Normal Operation (Auto Powerdown Enabled) Powerdown Due to Auto Powerdown Logic Manual Powerdown Manual Powerdown H H H H H H L L L L H H L L L L X X X X L H L H L H L H L H Active Active Active Active High-Z High-Z High-Z High-Z High-Z High-Z Active High-Z Active High-Z Active High-Z Active High-Z Active High-Z N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. L L H H L L H H L L Normal Operation (Auto Powerdown Disabled) Normal Operation (Auto Powerdown Enabled) Powerdown Due to Auto Powerdown Logic Manual Powerdown Manual Powerdown w/Rcvr. Disabled Manual Powerdown Manual Powerdown w/Rcvr. Disabled L L H H N.A. N.A. N.A. N.A. L H L H High-Z High-Z Active Active Active High-Z Active High-Z Active Active Active Active N.A. N.A. N.A. N.A. Manual Powerdown Manual Powerdown w/Rcvr. Disabled Normal Operation Normal Operation w/Rcvr. Disabled
3-12
ICL3221 thru ICL3243
VCC VCC CURRENT FLOW VOUT = VCC Rx POWERED DOWN UART Tx GND SHDN = GND OLD RS-232 CHIP POWER MANAGEMENT UNIT MASTER POWERDOWN LINE 0.1F 1M
VCC
With any of the above control schemes, the time required to exit powerdown, and resume transmission is only 100s. A mouse, or other application, may need more time to wake up from shutdown. If automatic powerdown is being utilized, the RS-232 device will reenter powerdown if valid receiver levels aren't reestablished within 30s of the ICL32XX powering up. Figure 5 illustrates a circuit that keeps the ICL32XX from initiating automatic powerdown for 100ms after powering up. This gives the slow-to-wake peripheral circuit time to reestablish valid RS-232 output levels.
FIGURE 2. POWER DRAIN THROUGH POWERED DOWN PERIPHERAL
FORCEOFF
FORCEON
VCC
ICL3221/23/43
TRANSITION DETECTOR TO WAKE-UP LOGIC VCC R2OUTB RX POWERED DOWN UART VOUT = HI-Z R2OUT TX T1IN T1OUT FORCEOFF = GND OR SHDN = GND, EN = VCC R2IN ICL324X
FIGURE 5. CIRCUIT TO PREVENT AUTO POWERDOWN FOR 100ms AFTER FORCED POWERUP
Automatic Powerdown (ICL3221/23/43 Only)
Even greater power savings is available by using the devices which feature an automatic powerdown function. When no valid RS-232 voltages (see Figure 6) are sensed on any receiver input for 30s, the charge pump and transmitters powerdown, thereby reducing supply current to 1A. Invalid receiver levels occur whenever the driving peripheral's outputs are shut off (powered down) or when the RS-232 interface cable is disconnected. The ICL32XX powers back up whenever it detects a valid RS-232 voltage level on any receiver input. This automatic powerdown feature provides additional system power savings without changes to the existing operating system.
FIGURE 3. DISABLED RECEIVERS PREVENT POWER DRAIN
FORCEOFF PWR MGT LOGIC 2.7V FORCEON INVALID ICL3221/23/43 0.3V
VALID RS-232 LEVEL - ICL32XX IS ACTIVE INDETERMINATE - POWERDOWN MAY OR MAY NOT OCCUR
INVALID LEVEL - POWERDOWN OCCURS AFTER 30s -0.3V INDETERMINATE - POWERDOWN MAY OR MAY NOT OCCUR I/O UART CPU -2.7V VALID RS-232 LEVEL - ICL32XX IS ACTIVE
FIGURE 6. DEFINITION OF VALID RS-232 RECEIVER LEVELS
FIGURE 4. CONNECTIONS FOR MANUAL POWERDOWN WHEN NO VALID RECEIVER SIGNALS ARE PRESENT
Automatic powerdown operates when the FORCEON input is low, and the FORCEOFF input is high. Tying FORCEON high disables automatic powerdown, but manual powerdown is always available via the overriding FORCEOFF input. Table 2 summarizes the automatic powerdown functionality.
3-13
ICL3221 thru ICL3243
Devices with the automatic powerdown feature include an INVALID output signal, which switches low to indicate that invalid levels have persisted on all of the receiver inputs for more than 30s (see Figure 7). INVALID switches high 1s after detecting a valid RS-232 level on a receiver input. INVALID operates in all modes (forced or automatic powerdown, or forced on), so it is also useful for systems employing manual powerdown circuitry. When automatic powerdown is utilized, INVALID = 0 indicates that the ICL32XX is in powerdown mode.
RECEIVER INPUTS INVALID } REGION
usually rises at low temperatures and it influences the amount of ripple on V+ and V-.
TABLE 3. REQUIRED CAPACITOR VALUES VCC (V) 3.0 to 3.6 4.5 to 5.5 3.0 to 5.5 C1 (F) 0.1 0.047 0.1 C2, C3, C4 (F) 0.1 0.33 0.47
Power Supply Decoupling
In most circumstances a 0.1F 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.
TRANSMITTER OUTPUTS VCC 0 AUTOPWDN V+ VCC 0 V-
INVALID OUTPUT
tINVL
tINVH PWR UP
Transmitter Outputs when Exiting Powerdown
Figure 8 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 3k in parallel with 2500pF. Note that the transmitters enable only when the magnitude of the supplies exceed approximately 3V.
FIGURE 7. AUTOMATIC POWERDOWN AND INVALID TIMING DIAGRAMS
The time to recover from automatic powerdown mode is typically 100s.
5V/DIV
FORCEOFF T1
Receiver ENABLE Control (ICL3221/22/23/41 Only)
Several devices also feature 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.
2V/DIV
T2 VCC = +3.3V C1 - C4 = 0.1F TIME (20s/DIV.)
Capacitor Selection
The charge pumps require 0.1F capacitors for 3.3V 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). 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)
FIGURE 8. TRANSMITTER OUTPUTS WHEN EXITING POWERDOWN
Mouse Driveability
The ICL324X have been specifically designed to power a serial mouse while operating from low voltage supplies. Figure 9 shows the transmitter output voltages under increasing load current. The on-chip switching regulator ensures the transmitters will supply at least 5V during worst case conditions (15mA for paralleled V+ transmitters, 7.3mA for single V- transmitter). The Automatic Powerdown feature does not work with a mouse, so FORCEOFF and FORCEON should be connected to VCC.
3-14
ICL3221 thru ICL3243
6 TRANSMITTER OUTPUT VOLTAGE (V) 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 0 1 2 3 4 5 6 7 8 9 10 VCC T2 ICL3241/43 T3 VOUT VOUT R1OUT VCC = +3.3V C1 - C4 = 0.1F 5s/DIV. LOAD CURRENT PER TRANSMITTER (mA) VCC = 3.0V T1 VOUT+ T1OUT VOUT+ 5V/DIV. T1IN
FIGURE 11. LOOPBACK TEST AT 120kbps
FIGURE 9. TRANSMITTER OUTPUT VOLTAGE vs LOAD CURRENT (PER TRANSMITTER, i.e., DOUBLE CURRENT AXIS FOR TOTAL VOUT+ CURRENT)
5V/DIV. T1IN
High Data Rates
The ICL32XX maintain the RS-232 5V minimum transmitter output voltages even at high data rates. Figure 10 details a transmitter loopback test circuit, and Figure 11 illustrates the loopback test result at 120kbps. For this test, all transmitters were simultaneously driving RS-232 loads in parallel with 1000pF, at 120kbps. Figure 12 shows the loopback results for a single transmitter driving 1000pF and an RS-232 load at 250kbps. The static transmitters were also loaded with an RS-232 receiver.
VCC 0.1F +
T1OUT
R1OUT VCC = +3.3V C1 - C4 = 0.1F 2s/DIV.
FIGURE 12. LOOPBACK TEST AT 250kbps
+ C1 C1ICL32XX + C2 C2TIN ROUT EN VCC SHDN OR FORCEOFF TOUT RIN 5k 1000pF C2+ VC4 + C1+ VCC V+
+ C3
Interconnection with 3V and 5V Logic
The ICL32XX directly interface with most 5V logic families, including ACT and HCT CMOS. See Table 4 for more information on possible combinations of interconnections.
TABLE 4. LOGIC FAMILY COMPATIBILITY WITH VARIOUS SUPPLY VOLTAGES SYSTEM POWER-SUPPLY VOLTAGE (V) 3.3 5 5 VCC SUPPLY VOLTAGE (V) 3.3 5 3.3
COMPATIBILITY Compatible with all CMOS families. Compatible with all TTL and CMOS logic families. Compatible with ACT and HCT CMOS, and with TTL. Incompatible with AC, HC, or CD4000 CMOS.
FIGURE 10. TRANSMITTER LOOPBACK TEST CIRCUIT
3-15
ICL3221 thru ICL3243 Typical Performance Curves
7.5 TRANSMITTER OUTPUT VOLTAGE (V) 5.0 VOUT+ 2.5 1 TRANSMITTER AT 235kbps 1 OR 2 TRANSMITTERS AT 30kbps 0 -2.5 VOUT -5.0 -7.5 SLEW RATE (V/s) 20
VCC = 3.3V, TA = 25oC
25
15 -SLEW +SLEW 10
0
1000
2000
3000
4000
5000
5
0
1000
2000
3000
4000
5000
LOAD CAPACITANCE (pF)
LOAD CAPACITANCE (pF)
FIGURE 13. TRANSMITTER OUTPUT VOLTAGE vs LOAD CAPACITANCE
FIGURE 14. SLEW RATE vs LOAD CAPACITANCE
45 ICL3221 - ICL3232 40 235kbps SUPPLY CURRENT (mA) SUPPLY CURRENT (mA) 35 30 25 20 15 10 5 0 0 1000 2000 3000 4000 5000 LOAD CAPACITANCE (pF) 20kbps 120kbps
45 ICL324X 40 35 30 25 20 20kbps 15 10 5 0 0 1000 2000 3000 LOAD CAPACITANCE (pF) 4000 5000 120kbps 235kbps
FIGURE 15. SUPPLY CURRENT vs LOAD CAPACITANCE WHEN TRANSMITTING DATA
FIGURE 16. SUPPLY CURRENT vs LOAD CAPACITANCE WHEN TRANSMITTING DATA
3.5 3.0 SUPPLY CURRENT (mA) ICL3221 - ICL3232 2.5 2.0 1.5 1.0 0.5 ICL324X 0 2.5 3.0 3.5 4.0 4.5
NO LOAD ALL OUTPUTS STATIC
ICL324X
5.0
5.5
6.0
SUPPLY VOLTAGE (V)
FIGURE 17. SUPPLY CURRENT vs SUPPLY VOLTAGE
3-16
ICL3221 thru ICL3243 Die Characteristics
DIE DIMENSIONS: ICL3221/22/23/32: 100 mils x 100 mils (2540m x 2540m) ICL3241/43: 100 mils x 127 mils (2550m x 3230m) METALLIZATION: Type: Metal 1: AISi(1%) Thickness: Metal 1: 8kA Type: Metal 2: AISi (1%) Thickness: Metal 2: 10kA SUBSTRATE POTENTIAL (POWERED UP): GND PASSIVATION: Type: Silox Thickness: 13kA TRANSISTOR COUNT: ICL3221: 286 ICL3222: 338 ICL3223: 357 ICL3232: 296 ICL324X: 464 PROCESS: Si Gate CMOS
3-17

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