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 rights 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. a ADM101E 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 craft port tm tiny rs-232 transceiver for portable applications functional block diagram v cc gnd v sd t in 1 2 3 4 10 9 8 7 c1 c1+ t out 5 6 r out r in r1 t1 +5v to ?v voltage inverter 0.1 f 0.1 f 5v 0.1 f + + + ADM101E features 460 kbit/s transmission rate single 5 v power supply compatible with rs-232 input/output levels 0.1 f 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 a i cc ultralow power (1 a) shutdown mode 10-lead soic package applications mobile telephones palmtop computers pdas portable instrumentation gps receivers general description the ADM101E 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 gene rates an on-chip ? 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 f. 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 a. the transmitter is disabled during shutdown but the receiver remains functional. craft port is a trademark of analog devices, inc. 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 soic 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.
rev. a C2C ADM101E?pecifications (v cc = 5 v 10%, c1 = c2 = 0.1 f. all specifications t min to t max unless otherwise noted.) parameter min typ max unit test conditions/comments output voltage swing 3.5 4.2 v v cc = 5 v 5%, t out loaded with 3 k ? to gnd 3.25 4.2 v v cc = 5 v 10%, t out loaded with 3 k ? to gnd v cc power supply current (unloaded) 0.5 1 ma no load, t in = v cc or gnd v cc power supply current (loaded) 1.85 2.5 ma t out loaded with 3 k ? to gnd v cc power supply current (shutdown) 1 a sd input = v cc input logic threshold low, v inl 0.8 v input logic threshold high, v inh 2.4 v input leakage current 1 a rs-232 input voltage range ?5 +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 357k ? ttl/cmos output voltage low, v ol 0.4 v i out = 1.6 ma ttl/cmos output voltage high, v oh 3.5 v i out = ?.0 ma propagation delay 0.25 s rs-232 to ttl instantaneous slew rate 1 25 v/ sc l = 10 pf, r l = 3 k ? ? k ? , t a = 25 c transition region slew rate 11 v/ sr l = 3 k ? , c l = 1000 pf measured from +3 v to ? v or vice versa baud rate 460 kb r l = 3 k ? , c l = 1 nf output resistance 300 ? v cc = 0 v, v out = 2 v rs-232 output short circuit current 25 60 ma notes 1 sample tested to ensure compliance. specifications subject to change without notice. absolute maximum ratings * (t a = 25 c unless otherwise noted) v cc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 v v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3 v to ? v input voltages driver input t in . . . . . . . . . . . . . . ?.3 v to (v cc , +0.3 v) receiver input r in . . . . . . . . . . . . . . . . . . . . . . . . . . 30 v output voltages driver output t out . . . . . . . (v cc , +0.3 v) to (v? ?.3 v) receiver output r out . . . . . . . . . . ?.3 v to (v cc +0.3 v) short circuit duration t out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . continuous power dissipation rm-10 (derate 12 mw/ c above 70 c) . . . . . . . . . 1488 mw thermal impedance . . . . . . . . . . . . . . . . . . . . . . . . 135 c/w operating temperature range industrial (a version) . . . . . . . . . . . . . . . ?0 c to +85 c storage temperature range . . . . . . . . . . . . ?5 c to +150 c lead temperature soldering vapor phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . 215 c infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 c esd rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . >2000 v esd rating (i-o pins) . . . . . . . . . . . . . . . . . . . . . . . . . 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. ordering guide temperature package package model range description option ADM101Earm ?0 c to +85 c soic rm-10
rev. a ADM101E C3C pin function descriptions pin no. mnemonic function 1 gnd ground pin. must be connected to 0 v. 2 c1 negative terminal of c1 (if c1 is polarized capacitor). 3 v internally generated negative supply voltage. 4t in driver input (3 v to 5 v ttl/cmos logic levels). 5r out receiver output (3 v to 5 v ttl/cmos logic levels). 6r in receiver input (eia-232 signal levels). 7t out driver output (eia-232 signal levels). 8 sd shutdown input. logic 1 on this input puts the ADM101E into low power shutdown mode. 9 c1+ positive terminal of charge pump capacitor (if c1 is polarized capacitor). 10 v cc positive power supply, nominally 5 v. pin configuration gnd v sd t in 1 2 3 4 10 9 8 7 ADM101E top view (not to scale) c1 c1+ t out 5 6 r out r in v cc typical performance characteristics current ma 0 1 6 0 25 5 charge pump voltage volts 10 15 20 2 3 4 5 tpc 1. charge pump voltage vs. current load capacitance pf 14 12 0 0 3500 500 i dd ma 1000 1500 2000 10 8 6 4 2500 3000 2 %&'" ) '
*+,-.
rev. a ADM101E C4C load capacitance pf 6 5 5 0 500 t x o/p volts 1000 1500 2000 4 3 2 1 2500 0 1 2 3 4 t x hi t x lo tpc 3. t ransmitter output voltage vs. load capacitance @ 460 kbps v cc volts 6 6 01 t x o/p hi & lo 23 4 4 2 5 0 2 4 t x hi t x lo 67 tpc 4. tx output voltage vs. supply data rate kb p s 40 40 0 100 slew rate volts/ s 200 300 400 30 20 10 0 10 500 600 20 30 series 1 series 2 tpc 5. slew rate vs. data rate load current ma 5 5 02 t x output voltage 468 4 3 2 1 0 10 12 1 2 t x lo 3 4 14 t x hi tpc 6. transmitter output voltage vs. load current
rev. a ADM101E C5C general description the ADM101E 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 communica tion 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, ? 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 ? v rail. it consists of an on-chip 200 khz oscillator, switching matrix and two external capacitors, as shown in figure 1. internal oscillator gnd c2 c1 s1 s2 s3 s4 v cc gnd v = v cc + + figure 1. charge pump dcCdc converter when s1 and s2 are closed, s3 and s4 are open, and c1 charges to +v cc . 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 ? cc , but will fall as the current drawn increases. charge pump capacitors and supply decoupling for proper operation of the charge pump, the capacitors should have an equivalent series resistance (esr) less than 1 ? . as the charge pump draws current pulses from v cc , the v cc decou- pling capacitor should also have low esr. the v cc decoupling capacitor and v?reservoir capacitor should also have low esr because they determine how effectively esd pulses are clamped to v cc 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 v cc = 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 k ? 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 k ? 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 times. 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.
rev. a ADM101E C6C outline dimensions dimensions shown in inches and (mm). c00053C0C2/01 (rev. a) printed in u.s.a. 10-lead soic (rm-10) 0.120 (3.05) 0.112 (2.85) 6 0 0.028 (0.70) 0.016 (0.40) 0.009 (0.23) 0.005 (0.13) 10 6 5 1 0.0197 (0.50) bsc 0.122 (3.10) 0.114 (2.90) 0.199 (5.05) 0.187 (4.75) pin 1 0.122 (3.10) 0.114 (2.90) 0.012 (0.30) 0.006 (0.15) 0.037 (0.94) 0.031 (0.78) seating plane 0.120 (3.05) 0.112 (2.85) 0.043 (1.10) max 0.006 (0.15) 0.002 (0.05) ADM101E?evision history location page data sheet changed from rev. 0 to rev. a. changes made to outline dimensions (rm-10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
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