View MAX3386E_2026058.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

general description the MAX3386E 3v-powered eia/tia-232 and v.28/v.24 is a communications interface with low power require- ments, high data-rate capabilities, and enhanced elec- trostatic discharge (esd) protection. the MAX3386E has two receivers and three transmitters. all rs-232 inputs and outputs are protected to ?5kv using the iec 1000-4-2 air-gap discharge method, ?kv using the iec 1000-4-2 contact discharge method, and ?5kv using the human body model. a proprietary low-dropout transmitter output stage enables true rs-232 performance from a +3.0v to +5.5v supply with a dual charge pump. the charge pump requires only four small 0.1? capacitors for operation from a +3.3v supply. the MAX3386E is capable of running at data rates up to 250kbps while maintaining rs-232 compliant output levels. the MAX3386E has a unique v l pin that allows interop- eration in mixed-logic voltage systems. both input and output logic levels are pin programmable through the v l pin. the MAX3386E is available in a space-saving tssop package. applications subnotebook/palmtop computers pdas and pda cradles cell phone data cables battery-powered equipment hand-held equipment peripherals features v l pin for compatibility with mixed-voltage systems enhanced esd protection on rx inputs and tx outputs ?5kv?uman body model ?5kv?ec 1000-4-2, air-gap discharge ?kv?ec 1000-4-2, contact discharge low 300? supply current guaranteed 250kbps data rate 1? low-power shutdown meets eia/tia-232 specifications down to 3.0v MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones ________________________________________________________________ maxim integrated products 1 20 19 18 17 16 15 14 13 1 2 3 4 5 6 7 8 shdn v cc gnd t1out c2+ c1- v+ c1+ top view t2out t3out r1in r2in t2in t1in v- c2- 12 11 9 10 v l r1out r2out t3in tssop MAX3386E MAX3386E r2out 10 r1out v l 11 r2in 13 gnd 18 rs-232 outputs ttl/cmos inputs t2in 8 t1in 7 c2- 5 c2+ 4 c1- 3 c1+ 1 r1in 14 t2out 16 t1out 17 v- 6 v+ 2 v cc v l 12 19 c1 0.1 f c2 0.1 f c bypass +3.3v t3in 9 t3out 15 rs-232 inputs ttl/cmos outputs 5k ? 5k ? c3 0.1 f c4 0.1 f v l 20 shdn typical operating circuit 19-1529; rev 3; 4/01 part MAX3386Ecup MAX3386Eeup -40? to +85? 0? to +70? temp. range pin-package 20 tssop 20 tssop pin configuration ordering information for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com.
i out = -1ma MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones 2 _______________________________________________________________________________________ absolute maximum ratings dc electrical characteristics (v cc = v l = +3.0v to +5.5v; c1?4 = 0.1?, tested at +3.3v ?0%; c1 = 0.047?, c2?4 = 0.33?, tested at +5.0v ?0%; t a = t min to t max ; unless otherwise noted. typical values are at v cc = v l = +3.3v, t a = +25?.) stresses beyond those listed under ?bsolute maximum ratings?may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. note 1: v+ and v- can have maximum magnitudes of 7v, but their absolute difference cannot exceed 13v. v cc to gnd ..............................................................-0.3v to +6v v l to gnd...................................................-0.3v to (v cc + 0.3v) v+ to gnd ................................................................-0.3v to +7v v- to gnd .................................................................+0.3v to -7v v+ + ? v- ? (note 1) .............................................................. +13v input voltages t_in, shdn to gnd ...........................................-0.3v to +6v r_in to gnd ..................................................................?5v output voltages t_out to gnd............................................................?3.2v r_out.....................................................-0.3v to (v l + 0.3v) short-circuit duration t_out to gnd........................continuous continuous power dissipation (t a = +70?) 20-pin tssop (derate 7.0mw/? above +70?) .......559mw operating temperature ranges MAX3386Ecup .................................................0? to +70? MAX3386Eeup ..............................................-40? to +85? junction temperature ......................................................+150? storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? i out = 1.6ma r_out, receivers disabled t_in, shdn t_in, shdn shdn = gnd, all inputs at v cc or gnd shdn = v cc , no load conditions v 0.4 output voltage low ? ?.05 ?0 output leakage currents ? ?.01 ? input leakage current v 0.5 transmitter input hysteresis v 0.9 input logic threshold high 1.4 2.0 2.4 v 0.8 110 ? shutdown supply current ma 0.3 1 supply current units min typ max symbol parameter v l = 5.0v v l = 3.3v v l = 2.5v v l = 1.8v i out = -1ma v v l - v l - 0.6 0.1 output voltage high v l = 3.3v or 5.0v t_in, shdn 0.6 input logic threshold low v l = 2.5v v -25 +25 input voltage range t a = +25? v 0.8 1.2 input threshold low 0.6 1.5 v l = 5.0v v l = 3.3v t a = +25? v 1.8 2.4 input threshold high 1.5 2.4 v l = 5.0v v l = 3.3v v 0.5 input hysteresis 357 t a = +25? k ? input resistance dc characteristics (v cc = +3.3v or +5v, t a = +25?) logic inputs receiver outputs receiver inputs
MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones _______________________________________________________________________________________ 3 dc electrical characteristics (continued) (v cc = v l = +3.0v to +5.5v; c1?4 = 0.1?, tested at +3.3v ?0%; c1 = 0.047?, c2?4 = 0.33?, tested at +5.0v ?0%; t a = t min to t max ; unless otherwise noted. typical values are at v cc = v l = +3.3v, t a = +25?.) timing characteristics (v cc = v l = +3v to +5.5v; c1?4 = 0.1?, tested at +3.3v ?0%; c1 = 0.047?, c2?4 = 0.33?, tested at +5.0v ?0%; t a = t min to t max ; unless otherwise noted. typical values are at v cc = v l = +3.3v, t a = +25?.) iec 1000-4-2 air-gap discharge method human body model v t_out = ?2v, transmitters disabled; v cc = 0 or 3.0v to 5.5v v t_out = 0 v cc = v+ = v- = 0, transmitter output = ?v all transmitter outputs loaded with 3k ? to ground conditions ?5 ?5 ? ?5 output leakage current ma ?0 output short-circuit current ? 300 10m output resistance v ? ?.4 output voltage swing units min typ max symbol parameter r l = 3k ? , c l = 1000pf, one transmitter switching (note 2) ? v t_out ? > 3.7v receiver input to receiver output, c l = 150pf conditions 630 ns 50 ? t phl - t plh ? receiver skew ns 100 ? t phl - t plh ? transmitter skew ? 100 time to exit shutdown ns 200 receiver output disable time ns 200 receiver output enable time ? 0.15 t plh receiver propagation delay kbps 250 maximum data rate 0.15 t phl units min typ max symbol parameter iec 1000-4-2 contact discharge method kv ? r_in, t_out esd protection v cc = 3.3v, t a = +25?, r l = 3k ? to 7k ? , measured from +3v to -3v or -3v to +3v v/? 430 transition-region slew rate c l = 150pf to 1000pf c l = 150pf to 2500pf note 2: transmitter skew is measured at the transmitter zero crosspoint. receiver inputs transmitter outputs esd protection
MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones 4 _______________________________________________________________________________________ typical operating characteristics (v cc = v l = +3.3v, t a = +25?, unless otherwise noted.) -7.5 -5.0 -2.5 0 2.5 5.0 7.5 0 1000 2000 3000 4000 5000 transmitter output voltage vs. load capacitance MAX3386E toc 01 load capacitance (pf) output voltage (v) data rate = 250kbps load = 3k ? in parallel with c l 0 2 4 6 8 10 12 14 16 0 1000 2000 3000 4000 5000 slew rate vs. load capacitance MAX3386E toc 02 load capacitance (pf) slew rate (v/?) slew rate + slew rate - -7.5 -5.0 -2.5 0 2.5 5.0 7.5 0 50 100 150 200 250 transmitter output voltage vs. data rate MAX3386E toc 03 data rate (kbps) output voltage (v) load = 3k ? , 1000pf one transmitter switching at data rate, other transmitters at 1/8 data rate 0 10 20 30 40 50 60 0 1000 2000 3000 4000 5000 supply current vs. load capacitance MAX3386E toc 04 load capacitance (pf) supply current (ma) 250kbps 120kbps 20kbps load = 3k ? , one transmitter switching at data rate, other transmitters at 1/8 data rate
MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones _______________________________________________________________________________________ 5 1 c1+ positive terminal of the voltage-doubler charge-pump capacitor pin description 2 v+ +5.5v supply generated by the charge pump 3 c1- negative terminal of the voltage-doubler charge-pump capacitor 4 c2+ positive terminal of the inverting charge-pump capacitor 5 c2- negative terminal of the inverting charge-pump capacitor 6 v- -5.5v generated by the charge pump 7 t1in 8 t2in 9 t3in ttl/cmos transmitter inputs 10 r2out 11 r1out 12 v l logic-level supply. all cmos inputs and outputs are referenced to this supply. 13 r2in 14 r1in 15 t3out 16 t2out 17 t1out rs-232 transmitter outputs 18 gnd ground 19 v cc +3.0v to +5.5v supply voltage 20 shdn shutdown input. 0 = shutdown, 1 = normal operation. name function pin ttl/cmos receiver outputs. swing between 0 and v l . rs-232 receiver inputs
MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones 6 _______________________________________________________________________________________ detailed description dual charge-pump voltage converter the MAX3386E? internal power supply consists of a regulated dual charge pump that provides output volt- ages of +5.5v (doubling charge pump) and -5.5v (inverting charge pump), regardless of the input voltage (v cc ) over a +3.0v to +5.5v range. the charge pumps operate in a discontinuous mode: if the output voltages are less than 5.5v, the charge pumps are enabled; if the output voltages exceed 5.5v, the charge pumps are disabled. each charge pump requires a flying capacitor (c1, c2) and a reservoir capacitor (c3, c4) to generate the v+ and v- supplies. rs-232 transmitters the transmitters are inverting level translators that convert cmos-logic levels to 5.0v eia/tia-232 levels. the MAX3386E? transmitters guarantee a 250kbps data rate with worst-case loads of 3k ? in parallel with 1000pf, providing compatibility with pc-to-pc communication software (such as laplink). transmitters can be paral- leled to drive multiple receivers or mice. figure 1 shows a complete system connection. these rs-232 output stages are turned off (high impedance) when the device is in shutdown mode. when the power is off, the MAX3386E permits the outputs to be driven up to ?2v. the transmitter inputs do not have pull-up resistors. connect unused inputs to gnd or v l . rs-232 receivers the receivers convert rs-232 signals to cmos-logic output levels. the MAX3386E? receivers have inverting three-state outputs, which depend on the shutdown state of the device. shutdown mode supply current falls to less than 1? when the MAX3386E is placed in shutdown mode ( shdn logic low). when shut down, the device? charge pumps are turned off, v+ decays to v cc , v- is pulled to ground, and the transmitter outputs are disabled (high impedance). the time required to exit shutdown is typically 100?, as shown in figure 2. connect shdn to v cc if the shutdown mode is not used. in shutdown mode, the receiver outputs are high impedance (table 1). MAX3386E i/o chip with uart cpu rs-232 power- management unit or keyboard controller shdn v l v cc i/o chip power supply figure 1. interface under control of pmu laplink is a trademark of traveling software. 50 s/div t2 t1 5v/div 2v/div v cc = 3.3v c1?4 = 0.1 f figure 2. transmitter outputs when exiting shutdown table 1. shutdown logic truth table transmitter outputs inactive l high-z charge pump active h active active high-z shdn receiver outputs
MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones _______________________________________________________________________________________ 7 v l logic supply input unlike other rs-232 interface devices where the receiver outputs swing between 0 and v cc , the MAX3386E fea- tures a separate logic supply input (v l ) that sets v oh for the receiver outputs and sets thresholds for the transmitted and shutdown inputs. this feature allows a great deal of flexibility in interfacing to many different types of systems with different logic levels. connect this input to the host logic supply (1.8v v l v cc ). also see the typical pda/cell-phone application sec- tion. 25kv esd protection as with all maxim devices, esd-protection structures are incorporated on all pins to protect against electrostatic discharges (esds) encountered during handling and assembly. the MAX3386E? driver outputs and receiver inputs have extra protection against static electricity. maxim has developed state-of-the-art structures to pro- tect these pins against an esd of ?5kv without damage. the esd structures withstand high esd in all states: nor- mal operation, shutdown, and powered down. after an esd event, maxim? ??version devices keep working without latchup, whereas competing rs-232 products can latch and must be powered down to remove latchup. esd protection can be tested in various ways. the trans- mitter outputs and receiver inputs of this product family are characterized for protection to the following limits: 1) ?5kv using the human body model 2) ?kv using the contact discharge method specified in iec 1000-4-2 3) ?5kv using iec 1000-4-2? air-gap discharge method esd test conditions esd performance depends on a variety of conditions. contact maxim for a reliability report that documents test setup, methodology, and results. human body model figure 3a shows the human body model, and figure 3b shows the current waveform it generates when dis- charged into a low impedance. this model consists of a 100pf capacitor charged to the esd voltage of interest, which is then discharged into the test device through a 1.5k ? resistor. iec 1000-4-2 the iec 1000-4-2 standard covers esd testing and performance of finished equipment; it does not specifi- cally refer to ics. the MAX3386E helps you design equipment that meets level 4 (the highest level) of iec 1000-4-2, without the need for additional esd-protection components. the major difference between tests done using the human body model and iec 1000-4-2 is higher peak current in iec 1000-4-2, because series resistance is lower in the iec 1000-4-2 model. hence, the esd with- stand voltage measured to iec 1000-4-2 is generally lower than that measured using the human body model. figure 4a shows the iec 1000-4-2 model, and figure 4b shows the current waveform for the ?kv iec 1000-4-2 level 4 esd contact-discharge test. the air-gap test involves approaching the device with a charged probe. the contact-discharge method connects the probe to the device before the probe is energized. charge-current limit resistor discharge resistance storage capacitor c s 100pf r c 1m ? r d 1500 ? high- voltage dc source device under test figure 3a. human body esd test model i p 100% 90% 36.8% t rl time t dl current waveform peak-to-peak ringing (not drawn to scale) i r 10% 0 0 amperes figure 3b. human body current waveform
machine model the machine model for esd tests all pins using a 200pf storage capacitor and zero discharge resis- tance. its objective is to emulate the stress caused by contact that occurs with handling and assembly during manufacturing. all pins require this protection during manufacturing, not just rs-232 inputs and outputs. therefore, after pc board assembly, the machine model is less relevant to i/o ports. __________applications information capacitor selection the capacitor type used for c1?4 is not critical for proper operation; polarized or nonpolarized capacitors can be used. the charge pump requires 0.1? capacitors for 3.3v operation. for other supply voltages, see table 2 for required capacitor values. do not use values smaller than those listed in table 2. increasing the capacitor values (e.g., by a factor of 2) reduces ripple on the transmitter outputs and slightly reduces power consumption. c2, c3, and c4 can be increased without changing c1? value. however, do not increase c1 without also increasing the values of c2, c3, and c4 to maintain the proper ratios (c1 to the other capacitors). when using the minimum required capacitor values, make sure the capacitor value does not degrade excessively with temperature. if in doubt, use capacitors with a larger nominal value. the capacitor? equivalent series resistance (esr), which usually rises at low tem- peratures, influences the amount of ripple on v+ and v-. power-supply decoupling in most circumstances, a 0.1? bypass capacitor is adequate. in applications that are sensitive to power- supply noise, decouple v cc to ground with a capacitor of the same value as charge-pump capacitor c1. connect bypass capacitors as close to the ic as possible. operation down to 2.7v transmitter outputs will meet eia/tia-562 levels of ?.7v with supply voltages as low as +2.7v. transmitter outputs when exiting shutdown figure 2 shows two transmitter outputs when exiting shutdown mode. as they become active, the two transmitter outputs are shown going to opposite rs-232 levels (one transmitter input is high; the other is low). each transmitter is loaded with 3k ? in parallel with 2500pf. the transmitter outputs display no ringing or undesirable transients as they come out of shutdown. note that the transmitters are enabled only when the magnitude of v- exceeds approximately 3v. MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones 8 _______________________________________________________________________________________ charge-current limit resistor discharge resistance storage capacitor c s 150pf r c 50m ? to 100m ? r d 330 ? high- voltage dc source device under test figure 4a. iec 1000-4-2 esd test model t r = 0.7ns to 1ns 30ns 60ns t 100% 90% 10% i peak i figure 4b. iec 1000-4-2 esd generator current waveform v cc (v) 0.1 0.1 c2, c3, c4 (f) 3.0 to 3.6 0.33 0.047 1 0.22 3.0 to 5.5 4.5 to 5.5 c1 (f) table 2. minimum required capacitor values
MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones high data rates the MAX3386E maintains the rs-232 ?.0v minimum transmitter output voltage even at high data rates. figure 5 shows a transmitter loopback test circuit. figure 6 shows a loopback test result at 120kbps, and figure 7 shows the same test at 250kbps. for figure 6, all transmit- ters were driven simultaneously at 120kbps into rs-232 loads in parallel with 1000pf. for figure 7, a single trans- mitter was driven at 250kbps, and all transmitters were loaded with an rs-232 receiver in parallel with 1000pf. interconnection with 3v and 5v logic the MAX3386E can directly interface with various 5v logic families, including act and hct cmos. the logic voltage power-supply pin v l sets the output voltage level of the receivers and the input thresholds of the transmitters. typical pda/cell-phone application the MAX3386E is designed with pda applications in mind. two transmitters and two receivers handle stan- dard full-duplex communication protocol, while an extra transmitter allows a ring indicator (ri) signal to alert the uart on the pc. without the ring indicator transmitter, solutions for these applications would require software- intensive polling of the cradle inputs. the ri signal is generated when a pda, cellular phone, or other ?radled?device is plugged into its cradle. this generates a logic-low signal to ri transmitter input, creat- ing +6v at the ring indicate pin. the pc? uart ri input is the only pin that can generate an interrupt from signals arriving through the rs-232 port. the interrupt routine for this uart will then service the rs-232 full-duplex com- munication between the pda and the pc. as cell phone design becomes more like that of pdas, cell phones will require similar docking ability and com- munication protocol. cell phones operate on a single lithium-ion (li+) battery and work with a power-supply voltage of +2.7v to +4v. the baseband logic coming from the phone connector can be as low as 1.8v at the transceivers. to prevent forward biasing of a device internal to the cell phone, the MAX3386E comes with a logic power-supply pin (v l ) that limits the logic levels presented to the phone. the receiver outputs will sink to zero for low outputs, but will not exceed v l for logic highs. the input logic levels for the transmitters are also altered, scaled by the magnitude of the v l input. the device will work with v l as low as 1.8v before the charge-pump noise will begin to cause the transmitter outputs to oscillate. this is useful with cell phones and other power-efficient devices with core logic voltage levels that go as low as 1.8v. MAX3386E 5k ? r_ in r_ out c2- c2+ c1- c1+ v- v+ v cc c4 c3 c1 c2 0.1 f v cc shdn t_ out t_ in gnd v cc 1000pf figure 5. loopback test circuit 2 s/div t1in t1out r1out 5v/div 5v/div 5v/div v cc = +3.3v figure 6. loopback test results at 120kbps _______________________________________________________________________________________ 9
chip information transistor count: 1267 MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones 10 ______________________________________________________________________________________ 2 s/div t1in t1out r1out 5v/div 5v/div 5v/div v cc = +3.3v figure 7. loopback test results at 250kbps
MAX3386E 3.0v, 25kv esd-protected rs-232 transceiver for pdas and cell phones package information tssop.eps maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. 11 ____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 ? 2001 maxim integrated products printed usa is a registered trademark of maxim integrated products.

▲Up To Search▲

Price & Availability of MAX3386E

	To Download MAX3386E Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .