ANALOG DEVICES ADM101E English products handbook Rev A
Contents
1. For proper operation of the charge pump the capacitors should have an equivalent series resistance ESR less than 1 Q As the charge pump draws current pulses from Vcc the Vec decou pling capacitor should also have low ESR The Vcc decoupling capacitor and V reservoir capacitor should also have low ESR because they determine how effectively ESD pulses are clamped to Vec or V by the on chip clamp diodes Tantalum or mono lithic ceramic capacitors are suitable for these components If using tantalum capacitors do not forget to observe polarity Transmitter Driver Section The driver converts 5 V logic input levels into RS 232 compat ible output levels With Vcc 5 V and driving an EIA 232 load the output voltage swing is typically 4 2 V Receiver Section The receivers are inverting level shifters that accept EIA 232 input levels and translate them into 5 V logic output levels The inputs have internal 5 kQ pull down resistors to ground and are also protected against overvoltages of up to 25 V The guaranteed switching thresholds are 0 8 V minimum and 2 8 V maximum An unconnected receiver input is pulled to 0 V by the internal 5 kQ pull down resistor This therefore results in a Logic 1 output level for unconnected inputs or for inputs con nected to GND The receivers have Schmitt trigger input with a hysteresis level of 0 25 V This ensures error free reception for both noisy inputs and for inputs with slow transition times2. SHUTDOWN INPUT The shutdown input allows the ADM101E to be put into an ultralow power mode where the dc dc converter is switched off and the transmitter is disabled The receiver remains active during shutdown Logic 0 at this input enables the ADM101E while a Logic 1 at this input shuts down the ADM101E ADMI01E OUTLINE DIMENSIONS Dimensions shown in inches and mm 10 Lead pSOIC RM 10 0 122 3 10 0 122 3 10 0 199 5 05 0 114 2 90 0 187 4 75 gt e 0 0197 0 50 BSC 0 120 3 05 rasi 0 112 2 85 z ii a Fe Guana 0 043 1 10 0 120 3 05 fren 0 031 0 78 MAX ei be e P 0 006 0 15 0 012 0 30 aoe T o o Ea 70 0 002 0 05 0 006 0 15 0 009 0 23 30161040 0 005 0 13 016 0 40 ADM101E Revision History Location Data sheet changed from REV 0 to REV A Changes made to Outline Dimensions RM 10 0 cece ee eee REV A C00053 0 2 01 rev A PRINTED IN U S A
3. Cl Positive Terminal of Charge Pump Capacitor Gf C1 is Polarized Capacitor 10 Vec Positive Power Supply Nominally 5 V 0 14 a 1 12 s l 10 w fj 2 ari lt 8 e gt 3 1 a a 26 gt a w ae 4 lt a I oO f a 6 ye 0 0 5 10 15 20 25 0 500 1000 1500 2000 2500 3000 3500 CURRENT mA TPC 1 Charge Pump Voltage vs Current REV A LOAD CAPACITANCE pF TPC 2 Ipp vs Load Capacitance 460 kbps ADM101E TxO P Volts 6 p Ty Hi 5 4 3 2 1 0 1 2 3 Tx LO 4 5 0 500 1000 1500 2000 2500 LOAD CAPACITANCE pF TPC 3 Transmitter Output Voltage vs Load Capacitance 460 kbps TxO P HI amp LO 4 6 Tx HI T LO 1 2 3 4 5 6 7 Vec Volts TPC 4 Tx Output Voltage vs Supply SLEW RATE Volts ps 0 100 200 300 400 500 600 DATA RATE kbps TPC 5 Slew Rate vs Data Rate 4 Tx HI 3 w O 2 a 1 0 gt 5 0 a 5 1 2 Tx LO 3 4 5 0 2 4 6 8 10 12 14 LOAD CURRENT mA TPC 6 Transmitter Output Voltage vs Load Current REV A GENERAL DESCRIPTION The ADMI101E is an RS 232 compatible line driver receiver in the Analog Devices Craft Port series containing one driver trans mitter and one receiver It is ideal for serial c
4. ANALOG DEVICES Craft Port Tiny RS 232 Transceiver for Portable Applications FUNCTIONAL BLOCK DIAGRAM FEATURES 460 kbit s Transmission Rate Single 5 V Power Supply Compatible with RS 232 Input Output Levels 0 1 uF Charge Pump Capacitors One Driver and One Receiver On Board DC DC Converter 4 2 V Output Swing with 5 V Supply Low Power BiCMOS 500 pA lcc Ultralow Power 1 pA Shutdown Mode 10 Lead SOIC Package APPLICATIONS Mobile Telephones Palmtop Computers PDAs Portable Instrumentation GPS Receivers GENERAL DESCRIPTION The ADMI101E is a single channel RS 232 driver and receiver in the Analog Devices Craft Port series designed to operate from a single 5 V supply A highly efficient charge pump voltage inverter generates an on chip 5 V supply which eliminates the need for a negative power supply for the driver and permits RS 232 compatible output levels to be developed using charge pump capacitors as small as 0 1 UF A shutdown input disables the charge pump and puts the device into a low power shutdown mode in which the current con sumption is typically less than 1 uA The transmitter is disabled during shutdown but the receiver remains functional Craft Port is a trademark of Analog Devices Inc REV A Information furnished by Analog Devices is believed to be accurate and reliable However no responsibility is assumed by Analog Devices for its use nor for any infringements of patents or other ri
5. a ca ant nase a E a leN Continuous Power Dissipation RM 10 Derate 12 mW C above 70 C 1488 mW Thermal Impedance 0 eee eens 135 C W Operating Temperature Range Industrial A Version 40 C to 85 C Storage Temperature Range 65 C to 150 C Lead Temperature Soldering Vapor Phase 60 sec 00 eee eee eee 215 C Infrared 15 S in ices we ka ceed ad oa 220 C ESD Rating so sek oe pti eee See dae du Ge gt 2000 V ESD Rating I O Pins 0 000 15 kV This is a stress rating only functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied Exposure to absolute maximum rating conditions for extended periods of time may affect reliability 2 REV A PIN FUNCTION DESCRIPTIONS PIN CONFIGURATION Pin No Mnemonic Function enD 1 o Voc GND Ground Pin Must be connected to 0 V os ADM101E 2 ets 2 Cl Negative Terminal of C1 if C1 is Polarized v 3 iseto Senet 8 sp Capacitor Tw 4 Tout 3 V Internally Generated Negative Supply Voltage Rout 5 6 Rin Tw Driver Input 3 V to 5 V TTL CMOS Logic Levels 5 Rout Receiver Output 3 V to 5 V TTL CMOS Logic Levels 6 Rw Receiver Input EIA 232 Signal Levels 7 Tour Driver Output EJA 232 Signal Levels 8 SD Shutdown Input Logic 1 on this input puts the ADM101E into low power shutdown mode 9
6. ghts of third parties which may result from its use No license is granted by implication or otherwise under any patent or patent rights of Analog Devices 5V TO 5V VOLTAGE INVERTER An epitaxial BiCMOS construction minimizes power consump tion to 3 mW and also guards against latch up Overvoltage protection is provided allowing the receiver inputs to withstand continuous voltages in excess of 30 V In addition all I O pins have ESD protection to levels greater than 15 kV The ADM101E is available in a 10 lead USOIC package which makes it ideal for serial communications in small portable applications such as palmtop computers and mobile telephones where a full RS 232 serial interface is not required but com pact size and low power drain are paramount One Technology Way P O Box 9106 Norwood MA 02062 9106 U S A Tel 781 329 4700 World Wide Web Site http www analog com Fax 781 326 8703 Analog Devices Inc 2001 ADM101E SPECIFICATION Vec 5V 10 C1 2 0 1 pF All specifications Ty to Tmax unless otherwise noted Parameter Min Typ Max Unit Test Conditions Comments Output Voltage Swing 3 5 4 2 V Vec 5 V 5 Tour Loaded with 3 kQ to GND 3 25 4 2 V Vec 5 V 10 Tour Loaded with 3 kQ to GND Vcc Power Supply Current Unloaded 0 5 1 mA No Load Tin Vcc or GND Vcc Power Supply Current Loaded 1 85 2 5 mA Tour Loaded with 3 kQ to GND Vcc Powe
7. ommunication in small portable devices such as mobile telephones palmtop per sonal computers and personal digital assistants where a full RS 232 serial interface is not required and only Tx and Rx lines are required for low speed communication between devices The ADM101E operates from a single 5 V supply and generates its own on chip 5 V power supply thus removing the need for a negative power supply for the driver CIRCUIT DESCRIPTION The internal circuitry consists of three main sections These are 1 A charge pump dc to dc converter 2 5 V logic to EIA 232 driver 3 EIA 232 to 5 V logic receiver Charge Pump DC DC Converter The dc dc converter generates a negative supply voltage from the 5 V supply thus removing the need for a separate 5 V rail It consists of an on chip 200 kHz oscillator switching matrix and two external capacitors as shown in Figure 1 Figure 1 Charge Pump DC DC Converter When S1 and S2 are closed S3 and S4 are open and Cl charges to Vcc S1 and S2 are then opened while S3 and S4 are closed to connect C1 across C2 dumping charge into C2 Since the positive terminal of C2 is at ground a negative voltage will be built up on its negative terminal with each cycle of the oscillator This voltage depends on the current drawn from C2 If the current is small the voltage will be close to Vcc but will fall as the current drawn increases REV A Charge Pump Capacitors And Supply Decoupling
8. r Supply Current Shutdown 1 uA SD Input Vec Input Logic Threshold Low Vini 0 8 V Input Logic Threshold High Vinu 2 4 V Input Leakage Current 1 uA RS 232 Input Voltage Range 15 15 V RS 232 Input Threshold Low 0 8 2 2 V RS 232 Input Threshold High 2 4 2 6 V RS 232 Input Hysteresis 0 2 V RS 232 Input Resistance 3 5 7 KQ TTL CMOS Output Voltage Low VoL 0 4 V Iour 1 6 mA TTL CMOS Output Voltage High Voy 3 5 V Iour 1 0 mA Propagation Delay 0 25 us RS 232 to TTL Instantaneous Slew Rate 25 V us C 10 pF Ry 3 kQ 7 kQ Ty 25 C Transition Region Slew Rate 11 V us Ri 3 kQ Cy 1000 pF Measured from 3 V to 3 V or Vice Versa Baud Rate 460 kB R 3 kQ CL 1 nF Output Resistance 300 Q Vece 0 V Vour 2 V RS 232 Output Short Circuit Current 25 60 mA NOTES Sample tested to ensure compliance Specifications subject to change without notice ABSOLUTE MAXIMUM RATINGS ORDERING GUIDE Ta 25 C unless otherwise noted Wie Aa Knees tree sheet aston ees bles So clase cei chs cho Oe ca taars 6V Temperature Package g Package Ne Se eel a Ret a a a a a ole a e ated 0 3 V to 6 V Model Range Description Option Input Voltages ADM101EARM 40 C to 85 C uSOIC RM 10 Driver Input Ty 0 3 V to Vcc 0 3 V Receiver Input Ry 1 eee 30 V Output Voltages Driver Output Tout Vcc 0 3 V to V 0 3 V Receiver Output RouT 0 3 V to Vcc 0 3 V Short Circuit Duration Toor eu Shag a 5b n
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ANALOG DEVICES ADM101E English products handbook Rev A