1 TC232* *Patented DUAL RS-232 TRANSMITTER/RECEIVER AND POWER SUPPLY 2 FEATURES GENERAL DESCRIPTION ■ ■ ■ ■ ■ ■ ■ ■ The TC232 is a dual RS-232 transmitter/receiver that complies with EIA /TIA RS-232E guidelines and is ideal for all RS-232 communication links. This device operates from a 5V power supply and contains two charge pump voltage converters that produce ±10V power supplies. The TC232 has four level translators. Two are RS-232 transmitters that convert TTL/CMOS input levels to 9V RS-232 outputs. The other two translators are RS-232 receivers that convert RS-232 inputs to 5V TTL/CMOS output levels. The receivers have a nominal threshold of 1.3V, a typical hysteresis of 0.5V, and can operate with inputs up to ±30V. Meets All RS-232 Specifications Operates From Single 5V Power Supply 2 Drivers and 2 Receivers On-Board Voltage Quadrupler Input Levels ...................................................... ±30V Output Swing With +5V Supply ........................ ±9V Low Supply Current ........................................ 5 mA Does not require external ±12V supplies APPLICATIONS ■ ■ ■ RS-232C Communication Links Modems, peripherals, computers Battery-powered systems + C1 1 + 2 – C1 3 + C2 4 – C2 5 V– 6 16 VCC 15 GND V T2 OUT 7 R2 IN 8 16 VCC 15 GND V 14 T1OUT 13 R1 IN TC232CPE TC232EPE TC232IJE TC232MJE + C1 1 + 2 – C1 3 + C2 4 – C2 5 V– 6 12 R1OUT 11 T1 IN 14 T1OUT 13 R1 IN TC232COE TC232EOE T2 OUT 7 10 T2 IN 9 R2 OUT 4 ORDERING INFORMATION PIN CONFIGURATIONS (DIP AND SOIC) 12 R1OUT 11 T1 IN 10 T2 IN R2 IN 8 9 R2 OUT Part No. Package TC232COE TC232CPE TC232EOE TC232EPE TC232IJE TC232MJE 16-Pin SOIC (Wide) 16-Pin Plastic DIP 16-Pin SOIC (Wide) 16-Pin Plastic DIP 16-Pin CerDIP 16-Pin CerDIP 3 Temp. Range 0°C to +70°C 0°C to +70°C – 40°C to +85°C – 40°C to +85°C – 25°C to +85°C – 55°C to +125°C 5 TYPICAL APPLICATION +5V INPUT C3* 10 µF + + 10 µF 6 16 1 C1 + 10 µF C2 + 10 µF + C1 3 – C1 4 + C2 5 – C2 VCC +5V TO +10V VOLTAGE DOUBLER V+ V– +10V TO –10V VOLTAGE INVERTER 2 +10V –10V 6 +5V + + C3* 10 µF C4 10 µF 400 kΩ 11 T1IN +5V TTL/CMOS INPUTS T1OUT 14 T1 RS-232 OUTPUTS 400 kΩ 10 T2IN 12 R1OUT T2 R1IN 13 R1 5 kΩ TTL/CMOS OUTPUTS 9 R2OUT 7 T2OUT 7 RS-232 INPUTS R2IN 8 R2 5 kΩ 8 GND *NOTE: C3 can be connected between V+ and VCC for convenience. 15 TC232-6 10/21/96 TELCOM SEMICONDUCTOR, INC. 6-3 DUAL RS-232 TRANSMITTER/ RECEIVER AND POWER SUPPLY TC232 ABSOLUTE MAXIMUM RATINGS* VCC ............................................................................. +6V V+ ........................................................................... +12V V– ........................................................................... +12V Input Voltages T1IN, T2IN .................................... –0.3 to (VCC +0.3V) R1IN, R2IN ......................................................... ±30V Output Voltages T1OUT, T2OUT ...................... (V+ +0.3V) to (V– –0.3V) R1OUT, R2OUT .............................. –0.3 to (VCC +0.3V) Short Circuit Duration V+ .................................................................... 30sec V– .................................................................... 30sec T1OUT, T2OUT .......................................... Continuous Storage Temperature Range .................. -65°C to +150°C Package Power Dissipation (TA ≤ 70°C) CerDIP ............................................................890mW Derate 9.5 mW/°C Above +70°C Plastic DIP ...................................................... 840mW Derate 7 mW/°C Above +70°C Small Outline (SOIC) ...................................... 760mW Derate 7 mW/°C Above +70°C *Static-sensitive device. Unused devices must be stored in conductive material. Protect devices from static discharge and static fields. Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS: VCC = 5V ±10%, TA = operating temperature range, test circuit unless otherwise noted. Parameter Test Conditions Output Voltage Swing T1OUT, T2OUT Loaded With 3 kΩ to Ground Power Supply Current Input Logic Threshold Low Input Logic Threshold High Logic Pull-Up Current RS-232 Input Voltage Operating Range RS-232 Input Threshold Low RS-232 Input Threshold High RS-232 Input Hysteresis RS-232 Input Resistance TTL/CMOS Output Voltage Low TTL/CMOS Output Voltage High Propagation Delay Instantaneous Slew Rate Transition Region Slew Rate Output Resistance RS-232 Output Short-Circuit Current T1IN, T2IN T1IN, T2IN T1IN, T2IN = 0V VCC = 5V VCC = 5V TA = +25°C, VCC = 5V IOUT = 3.2 mA IOUT = – 1 mA RS-232 to TTL or TTL to RS-232 CL = 10 pF, RL = 3 kΩ to 7 kΩ, TA = +25°C (Note 1) RL = 3 kΩ, CL = 2500 pF Measured From +3V to – 3V or –3V to +3V VCC = V+ = V– = 0V, VOUT = ±2V Min Typ Max Unit ±5 ±9 ±10 V — — 2 — – 30 0.8 — 0.2 3 — 3.5 — — 5 — — 15 — 1.2 1.7 0.5 5 — — 0.5 — 10 0.8 — 200 +30 — 2.4 1 7 0.4 — — 30 mA V V µA V V V V kΩ V V µsec V/µsec — 3 — V/µsec 300 — — ±10 — — Ω mA NOTE 1. Sample tested. 6-4 TELCOM SEMICONDUCTOR, INC. DUAL RS-232 TRANSMITTER/ RECEIVER AND POWER SUPPLY 1 TC232 DETAILED DESCRIPTION V+, V– Output Voltages vs Load Current The TC232 contains a +5V to ±10V dual charge pump voltage converter, a dual transmitter and a dual receiver. 10 9 Dual Transmitter TC232 transmitters are CMOS inverters driven by ±10V internally-generated voltages. The input is TTL/CMOS compatible, with a logic threshold of about 26% of VCC (1.3V for 5V VCC). The input of an unused transmitter can be left unconnected, since an internal 400 kΩ pull-up resistor connected between the transmitter input and VCC pulls the input HIGH and forces the unused transmitter output to the LOW state. With VCC at 5V, the outputs will go from (V+ – 0.6V) to V– with no load and will swing ±9V when loaded with 3 kΩ. The minimum output voltage swing, with VCC at 4.5V and at maximum ambient temperature, is ±5V. This conforms to RS-232 specifications for "worst-case" conditions. EIA/TIA RS-232E specs limit the slew rate at output to less than 30V/µs. The powered-down output impedance (VCC = 0V) is a minimum of 300Ω with ±2V applied to outputs. TELCOM SEMICONDUCTOR, INC. OUTPUT VOLTAGE (|V|) +5V to ±10V Dual Charge Pump Voltage Converter The TC232 power supply consists of two charge pumps. One uses external capacitor C1 to double the +5V input to +10V, with output impedance of about 200Ω. The other uses C2 to invert +10V to – 10V, with overall output impedance of 450Ω (including effects of +5V to +10V doubler impedance). The clock in the doubler circuit will start at ≈4.2V in the typical part, but external loads may make this point rise to as high as 4.5V with a load of 2 kΩ on each of the two output voltages. Because of this, use of the doubler and inverter to run additional external circuits should be limited. The maximum current should be no more than 2.5 mA from the +10V and - 10V. in order to guarantee start-up of the doubler clock. The test circuit employs 22 µF capacitors for C1 to C4, but the value is not critical. These capacitors usually are lowcost aluminum or tantalum electrolytic capacitors. Increasing C1 and C2 to 47 µF lowers the output impedance of the +10V doubler and the - 10V inverter by the change in the ESR of the capacitors. Increasing C3 and C4 lowers ripple on the ±10V outputs and 16 kHz ripple on the RS-232 outputs. Where size is critical, the value of C1 to C4 can be lowered to 1 µF. The use of a low ESR capacitor will help lower the output ripple and keep the output impedance of the ±10V as low as possible. V+ (VCC = 4.5V) 8 7 V– (VCC = 4.5V) 6 2 V+ (VCC = 5V) V– (VCC = 5V) 3 5 CONDITIONS: 4 A) TA = +25°C B) TRANSMITTER OUTPUTS OPEN CIRCUIT 3 0 1 2 3 4 5 6 7 8 |I | (mA) LOAD 9 10 4 The outputs are protected and can be short-circuited to ground indefinitely. Dual Receiver TC232 receivers meet RS-232 input specifications. Input impedance is between 3 kΩ and 7 kΩ. Switching thresholds are within the ±3V limits, and the receivers withstand up to ±30V inputs. RS-232 and TTL/CMOS input compatible, the receivers have 0.8V VIL and 2.4V VIH with 0.5V hysteresis to reject noise. The TTL/CMOS compatible receiver output is LOW when an RS-232 input is greater than 2.4V. It is HIGH when an input is floating or between +0.8V and – 30V. 6 TEST CIRCUIT +4.5V TO +5.5V INPUT TC232 C1 + 22 µF 22 µF + 1 + C1 V CC 16 2 V+ GND 15 3 – C1 T1OUT 14 4 + C2 R1IN 13 5 – C2 R1OUT 12 6 V– T1 IN 11 TTL/CMOS INPUT 7 T2 OUT T2 IN 10 TTL/CMOS INPUT 8 R2 IN C3 C2 22 µF + + C4 3 kΩ 22 µF RS-232 OUTPUT 5 3 kΩ R2OUT 9 RS-232 OUTPUT RS-232 INPUT ±30V 7 TTL/CMOS OUTPUT TTL/CMOS OUTPUT RS-232 INPUT ±30V 8 6-5