MAX481E/MAX483E/MAX485E/ MAX487E–MAX491E/MAX1487E
±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers______________________________________________________________Pin DescriptionPINMAX481E/MAX483EMAX485E/MAX487EMAX1487E12NAMEFUNCTIONMAX488EMAX490EMAX489EMAX491E2—23RO–—–REReceiver Output: If A > B by 200mV, RO will be high;If A < B by 200mV, RO will be low.–—–Receiver Output Enable. RO is enabled whenREis–—–low; RO is high impedance whenREis high.Driver Output Enable. The driver outputs, Y and Z, areenabled by bringing DE high. They are high imped-ance when DE is low. If the driver outputs are enabled,the parts function as line drivers. While they are high–—–impedance, theyfunction as line receivers ifREis low.Driver Input. A low on DI forces output Y low and out-put Z high. Similarly, a high on DI forces output Y highand output Z low.GroundNoninverting Driver OutputInverting Driver OutputNoninverting Receiver Input and Noninverting DriverOutputNoninverting Receiver InputInverting Receiver Input and Inverting Driver OutputInverting Receiver InputPositive Supply: 4.75V ≤VCC≤5.25VNo Connect—not internally connected3—4DE45——6—7—8—3456—8—71—56, 7910—12—11141, 8, 13DIGNDYZAABBVCCN.C.7
MAX481E/MAX483E/MAX485E/ MAX487E–MAX491E/MAX1487E
±15kV ESD-Protected, Slew-Rate-Limited,Low-Power, RS-485/RS-422 Transceivers__________Function Tables (MAX481E/MAX483E/MAX485E/MAX487E/MAX1487E)Table 1. Transmitting
INPUTSOUTPUTSREDEDIZYX1101X101000XHigh-ZHigh-Z10XHigh-Z*High-Z*X = Don't careHigh-Z = High impedance*Shutdown mode for MAX481E/MAX483E/MAX487E__________Applications InformationThe MAX481E/MAX483E/MAX485E/MAX487E–MAX491Eand MAX1487E are low-power transceivers for RS-485and RS-422 communications. These “E” versions of theMAX481, MAX483, MAX485, MAX487–MAX491, andMAX1487 provide extra protection against ESD. Therugged MAX481E, MAX483E, MAX485E, MAX497E–MAX491E, and MAX1487E are intended for harsh envi-ronments where high-speed communication is important.These devices eliminate the need for transient suppres-sor diodes and the associated high capacitance loading.The standard (non-“E”) MAX481, MAX483, MAX485,MAX487–MAX491, and MAX1487 are recommended forapplications where cost is critical.
The MAX481E, MAX485E, MAX490E, MAX491E, andMAX1487E can transmit and receive at data rates up to2.5Mbps, while the MAX483E, MAX487E, MAX488E,and MAX489E are specified for data rates up to250kbps. The MAX488E–MAX491E are full-duplextransceivers, while the MAX481E, MAX483E, MAX487E,and MAX1487E are half-duplex. In addition, driver-enable (DE) and receiver-enable (RE) pins are includedon the MAX481E, MAX483E, MAX485E, MAX487E,MAX489E, MAX491E, and MAX1487E. When disabled,the driver and receiver outputs are high impedance.
±15kV ESD ProtectionAs with all Maxim devices, ESD-protection structuresare incorporated on all pins to protect against electro-static discharges encountered during handling andassembly. The driver outputs and receiver inputs haveextra protection against static electricity. Maxim’s engi-
Maxim IntegratedTable 2. Receiving
INPUTSOUTPUTREDEA-BRO00>+0.2V100< -0.2V000Inputs open110XHigh-Z*X = Don't careHigh-Z = High impedance*Shutdown mode for MAX481E/MAX483E/MAX487Eneers developed state-of-the-art structures to protectthese pins against ESD of ±15kV without damage. TheESD structures withstand high ESD in all states: normaloperation, shutdown, and powered down. After an ESDevent, Maxim’s MAX481E, MAX483E, MAX485E, MAX487E–MAX491E, and MAX1487E keep workingwithout latchup.
ESD protection can be tested in various ways; thetransmitter outputs and receiver inputs of this productfamily are characterized for protection to ±15kV usingthe Human Body Model.
Other ESD test methodologies include IEC10004-2 con-tact discharge and IEC1000-4-2 air-gap discharge (for-merly IEC801-2).
ESD Test ConditionsESD performance depends on a variety of conditions.Contact Maxim for a reliability report that documentstest set-up, test methodology, and test results.
Human Body ModelFigure 4 shows the Human Body Model, and Figure 5shows the current waveform it generates when dis-charged into a low impedance. This model consists ofa 100pF capacitor charged to the ESD voltage of inter-est, which is then discharged into the test devicethrough a 1.5kΩresistor.
IEC1000-4-2The IEC1000-4-2 standard covers ESD testing and per-formance of finished equipment; it does not specificallyrefer to integrated circuits (Figure 6).
9
MEMORY存储芯片MAX488CSA+T中文规格书 - 图文
