DUAL RS-232 TRANSMITTER/RECEIVER AND POWER SUPPLY

Transcription

1 DUAL TRANSMITTER/ DUAL TRANSMITTER/ * *Patented FEATURES Meets All Specifications Operates From Single V Power Supply Drivers and Receivers On-Board Voltage Quadrupler Input Levels...±0V Output Swing With V Supply...±V Low Supply Current... ma Does not require external ±V supplies APPLICATIONS C Communication Links Modems, peripherals, computers Battery-powered systems PIN CONFIGURATIONS (DIP and SOIC) V T OUT CPE EPE IJE MJE VCC GND TOUT RIN ROUT TIN TIN R OUT V T OUT COE EOE VCC GND TOUT RIN ROUT TIN TIN R OUT GENERAL DESCRIPTION The is a dual transmitter/receiver that complies with EIA /TIA E guidelines and is ideal for all communication links. This device operates from a V power supply and contains two charge pump voltage converters that produce ±V power supplies. The has four level translators. Two are transmitters that convert input levels to V outputs. The other two translators are receivers that convert inputs to V output levels. The receivers have a nominal threshold of.v, a typical hysteresis of 0.V, and can operate with inputs up to ±0V. ORDERING INFORMATION Part No. Package Temp. Range COE -Pin SOIC (Wide) 0 C to 0 C CPE -Pin Plastic DIP 0 C to 0 C EOE -Pin SOIC (Wide) 0 C to C EPE -Pin Plastic DIP 0 C to C IJE -Pin CerDIP C to C MJE -Pin CerDIP C to C TYPICAL APPLICATION V C* C C V CC V TO V V VOLTAGE DOUBLER V TO V VOLTAGE INVERTER V V V C C* S 00 kω T IN V 00 kω T IN T T T OUT T OUT OUTPUTS R OUT R R IN OUTPUTS R OUT R kω S kω GND *NOTE: C can be connected between V and V CC for convenience. - // TelCom Semiconductor reserves the right to make changes in the circuitry and specifications of its devices.

2 DUAL TRANSMITTER/ ABSOLUTE MAXIMUM RATINGS* V CC... V V... V... V Input Voltages T IN, T IN to (V CC 0.V) R IN,... ±0V Output Voltages T OUT, T OUT... (V 0.V) to ( 0.V) R OUT, R OUT to (V CC 0.V) Short Circuit Duration V... 0sec... 0sec T OUT, T OUT... Continuous Storage Temperature Range... - C to C Package Power Dissipation (T A 0 C) CerDIP...0mW Derate. mw/ C Above 0 C Plastic DIP...0mW Derate mw/ C Above 0 C Small Outline (SOIC)...0mW Derate mw/ C Above 0 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: V CC = V ±%, T A = operating temperature range, test circuit unless otherwise noted. Parameter Test Conditions Min Typ Max Unit Output Voltage Swing T OUT, T OUT Loaded With ± ± ± V kω to Ground Power Supply Current ma Input Logic Threshold Low T IN, T IN 0. V Input Logic Threshold High T IN, T IN V Logic Pull-Up Current T IN, T IN = 0V 00 µa Input Voltage Operating Range 0 0 V Input Threshold Low V CC = V 0.. V Input Threshold High V CC = V.. V Input Hysteresis V Input Resistance T A = C, V CC = V kω Output Voltage Low I OUT =. ma 0. V Output Voltage High I OUT = ma. V Propagation Delay to TTL or TTL to 0. µsec Instantaneous Slew Rate C L = pf, R L = kω to kω, 0 V/µsec T A = C (Note ) Transition Region Slew Rate R L = kω, C L = 00 pf V/µsec Measured From V to V or V to V Output Resistance V CC = V = = 0V, V OUT = ±V 00 Ω Output ± ma Short-Circuit Current NOTE. Sample tested.

3 DUAL TRANSMITTER/ DETAILED DESCRIPTION The contains a V to ±V dual charge pump voltage converter, a dual transmitter and a dual receiver. V to ±V Dual Charge Pump Voltage Converter The power supply consists of two charge pumps. One uses external capacitor C to double the V input to V, with output impedance of about 00Ω. The other uses C to invert V to V, with overall output impedance of 0Ω (including effects of V to V doubler impedance). The clock in the doubler circuit will start at.v in the typical part, but external loads may make this point rise to as high as.v with a load of 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. ma from the V and - V. in order to guarantee start-up of the doubler clock. The test circuit employs capacitors for C to C, but the value is not critical. These capacitors usually are lowcost aluminum or tantalum electrolytic capacitors. Increasing C and C to µf lowers the output impedance of the V doubler and the - V inverter by the change in the ESR of the capacitors. Increasing C and C lowers ripple on the ±V outputs and khz ripple on the outputs. Where size is critical, the value of C to C can be lowered to µf. The use of a low ESR capacitor will help lower the output ripple and keep the output impedance of the ±V as low as possible. Dual Transmitter transmitters are CMOS inverters driven by ±V internally-generated voltages. The input is compatible, with a logic threshold of about % of V CC (.V for V V CC ). The input of an unused transmitter can be left unconnected, since an internal 00 kω pull-up resistor connected between the transmitter input and V CC pulls the input HIGH and forces the unused transmitter output to the LOW state. With V CC at V, the outputs will go from ( 0.V) to with no load and will swing ±V when loaded with kω. The minimum output voltage swing, with V CC at.v and at maximum ambient temperature, is ±V. This conforms to specifications for "worst-case" conditions. EIA/TIA E specs limit the slew rate at output to less than 0V/µs. The powered-down output impedance (V CC = 0V) is a minimum of 00Ω with ±V applied to outputs. TEST CIRCUIT C C OUTPUT OUTPUT VOLTAGE ( V ) V, Output Voltages vs. Load Current ±0V C C kω C V C C C T OUT V (V CC =.V) V (V CC = V) (V CC =.V) (V CC = V) CONDITIONS: A) T A = C B) TRANSMITTER OUTPUTS OPEN CIRCUIT 0 I (ma) LOAD The outputs are protected and can be short-circuited to ground indefinitely. Dual Receiver receivers meet input specifications. Input impedance is between kω and kω. Switching thresholds are within the ±V limits, and the receivers withstand up to ±0V inputs. and input compatible, the receivers have 0.V V IL and.v V IH with 0.V hysteresis to reject noise. The compatible receiver output is LOW when an input is greater than.v. It is HIGH when an input is floating or between 0.V and 0V. V CC GND T OUT R IN R OUT T IN T IN R OUT.V TO.V kω OUTPUT ±0V OUTPUT OUTPUT

4 DUAL TRANSMITTER/ PACKAGE DIMENSIONS -Pin Plastic DIP PIN.0 (.0).0 (.).0 (.). (.). (.).0 (.).00 (.0). (.). (.). (.).00 (.0).00 (0.).0 (0.).00 (0.0) MIN.. (.).00 (.).00 (.).0 (.).0 (0.).0 (0.).00 (.). (.) -Pin CerDIP PIN.00 (.). (.).00 (.0) MAX..00 (0.) MIN..0 (.).0 (.0).0 (.).0 (.).00 (.0). (.0).00 (.0).00 (0.).00 (.0). (.). (.) MIN..0 (0.).00 (0.0) MIN.. (.).00 (.).0 (.).0 (.).00 (.).0 (0.).00 (.).0 (.) Dimensions: inches (mm)

5 DUAL TRANSMITTER/ PACKAGE DIMENSIONS (Cont.) -Pin SOIC (Wide) PIN. (.).0 (.0). (.). (.). (.). (.).00 (.) TYP..0 (0.).0 (0.). (.).0 (.).0 (0.0).00 (0.) MAX..00 (.).0 (0.0).0 (0.).00 (0.) Dimensions: inches (mm) Sales Offices TelCom Semiconductor 00 Terra Bella Avenue P.O. Box Mountain View, CA 0- TEL: 0-- FAX: TelCom Semiconductor Austin Product Center Burnet Rd. Suite Austin, TX TEL: --0 FAX: -- TelCom Semiconductor H.K. Ltd. Sam Chuk Street, Ground Floor San Po Kong, Kowloon Hong Kong TEL: --0 FAX: -- Printed in the U.S.A.