TC232

TC232 TELCOM | Alldatasheet

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Technical content

6-3TELCOM SEMICONDUCTOR, INC. TC232* DUAL RS-232 TRANSMITTER/RECEIVER AND POWER SUPPLY 10 µF 400 kΩ 400 kΩ 5 kΩ Ω5 k RS-232 OUTPUTS RS-232 INPUTS C 1 10 µF TTL/CMOS INPUTS TTL/CMOS OUTPUTS +5V TO +10V VOLTAGE DOUBLER +10V TO –10V VOLTAGE INVERTER +5V +5V +5V INPUT +10V –10V 10 µF C 1 C 2 C 2 T2IN T1IN R1 IN R2 OUT R2 IN T2OUT T1OUT R1 OUT GND 10 µF C3* +10 µF 10 µF C3* VCC V + V – *NOTE: C3 can be connected between V+ and VCC for convenience.

FEATURES

n Meets All RS-232 Specifications n Operates From Single 5V Power Supply n 2 Drivers and 2 Receivers n On-Board Voltage Quadrupler n Does not require external ±12V supplies

APPLICATIONS

n RS-232C Communication Links n Modems, peripherals, computers n Battery-powered systems 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.

ORDERING INFORMATION

Part No. Package Temp. Range TC232COE 16-Pin SOIC (Wide) 0 °C to +70°C TC232CPE 16-Pin Plastic DIP 0 °C to +70°C TC232EOE 16-Pin SOIC (Wide) – 40 °C to +85°C TC232EPE 16-Pin Plastic DIP – 40 °C to +85°C TC232IJE 16-Pin CerDIP – 25 °C to +85°C TC232MJE 16-Pin CerDIP – 55 °C to +125°C PIN CONFIGURATIONS (DIP AND SOIC) TC232COE TC232EOE VCC R28R2 V + GND R1 IN T1IN OUT OUT T2IN OUTIN OUT V C + C – C + C – TC232CPE TC232EPE TC232IJE TC232MJE VCC R28R2 V + GND R1 IN T1IN OUT OUT T2IN OUTIN OUT V C + C – C + C – TYPICAL APPLICATION *Patented TC232-6 10/21/96

6-4 TELCOM SEMICONDUCTOR, INC. ABSOLUTE MAXIMUM RATINGS* Input Voltages Output Voltages Short Circuit Duration Package Power Dissipation (TA ≤ 70°C) Derate 9.5 mW/°C Above +70°C Derate 7 mW/°C Above +70°C Derate 7 mW/°C Above +70°C ELECTRICAL CHARACTERISTICS: VCC = 5V ±10%, TA = operating temperature range, test circuit unless otherwise noted. Parameter Test Conditions Min Typ Max Unit Output Voltage Swing T1 OUT , T2OUT Loaded With ±5 ±9 ±10 V 3 kΩ to Ground Power Supply Current — 5 10 mA Input Logic Threshold Low T1 IN, T2IN — — 0.8 V Input Logic Threshold High T1 IN, T2IN 2— — V Logic Pull-Up Current T1 IN, T2IN = 0V — 15 200 µA RS-232 Input Voltage Operating Range – 30 — +30 V RS-232 Input Threshold Low V CC = 5V 0.8 1.2 — V RS-232 Input Threshold High V CC = 5V — 1.7 2.4 V RS-232 Input Hysteresis 0.2 0.5 1 V RS-232 Input Resistance T A = +25°C, VCC = 5V 3 5 7 k Ω TTL/CMOS Output Voltage Low I OUT = 3.2 mA — — 0.4 V TTL/CMOS Output Voltage High I OUT = – 1 mA 3.5 — — V Propagation Delay RS-232 to TTL or TTL to RS-232 — 0.5 — µsec Instantaneous Slew Rate C L = 10 pF, RL = 3 kΩ to 7 kΩ ,— — 3 0 V / µsec TA = +25°C (Note 1) Transition Region Slew Rate R L = 3 kΩ , CL = 2500 pF — 3 — V/ µsec Measured From +3V to – 3V or –3V to +3V Output Resistance V CC = V+ = V– = 0V, VOUT = ±2V 300 — — Ω RS-232 Output — ±10 — mA Short-Circuit Current NOTE 1. Sample tested. *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 perma- nent 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. TC232 DUAL RS-232 TRANSMITTER/ RECEIVER AND POWER SUPPLY

6-5TELCOM SEMICONDUCTOR, INC. DETAILED DESCRIPTION The TC232 contains a +5V to ±10V dual charge pump voltage converter, a dual transmitter and a dual receiver. +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 low- cost 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 out- puts and 16 kHz ripple on the RS-232 outputs. Where size is critical, the value of C1 to C4 can be lowered to 1µF. 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. Dual Transmitter TC232 transmitters are CMOS inverters driven by ±10V internally-generated voltages. The input is TTL/CMOS com- patible, with a logic threshold of about 26% of V CC (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 V CC 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. V+, V– Output Voltages vs Load Current TEST CIRCUIT TC232 C 1 22 µF 22 µF C 2 22 µF 22 µF RS-232 INPUT ±30V RS-232 OUTPUT +4.5V TO +5.5V INPUT 3 kΩ RS-232 OUTPUT RS-232 INPUT ±30V TTL/CMOS OUTPUT TTL/CMOS INPUT TTL/CMOS INPUT TTL/CMOS OUTPUT 3 kΩ V + V – T2OUT R2 IN V CC GND T1OUT T1IN R1 OUT T2IN R2 OUT INR1 C + C – C + C – C 3 C 4 0 1234567891 0 OUTPUT VOLTAGE (|V|) (V = 4.5V)CC (V = 5V)CC (V = 4.5V)CC (V = 5V)CC CONDITIONS: A) T = +25°C B) TRANSMITTER OUTPUTS OPEN CIRCUIT A | I | (mA)LOAD –V –V 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. TC232 DUAL RS-232 TRANSMITTER/ RECEIVER AND POWER SUPPLY