Electronic Components Datasheet Search |
|
MAX3040ESE Datasheet(PDF) 9 Page - Maxim Integrated Products |
|
MAX3040ESE Datasheet(HTML) 9 Page - Maxim Integrated Products |
9 / 15 page ±10kV ESD-Protected, Quad 5V RS-485/RS-422 Transmitters _______________________________________________________________________________________ 9 IEC 1000-4-4 Burst/Electrical Fast Transient Test Levels (For Communication Lines) The stresses are applied while the MAX3040–MAX3045 are powered up. Test results are reported as: 1) Normal performance within the specification limits. 2) Temporary degradation or loss of function or perfor- mance which is self-recoverable. 3) Temporary degradation, loss of function or perfor- mance requiring operator intervention, such as sys- tem reset. 4) Degradation or loss of function not recoverable due to damage. The MAX3040–MAX3045 meets classification 2 listed above. Additionally, the MAX3040–MAX3045 will not latchup during the IEC burst stress events. Hot-Swap Capability Hot-Swap Inputs When circuit boards are plugged into a “hot” back- plane, there can be disturbances to the differential sig- nal levels that could be detected by receivers connected to the transmission line. This erroneous data could cause data errors to an RS-485/RS-422 system. To avoid this, the MAX3040–MAX3045 have hot-swap capable inputs. When a circuit board is plugged into a “hot” backplane there is an interval during which the processor is going through its power-up sequence. During this time, the processor’s output drivers are high impedance and will be unable to drive the enable inputs of the MAX3040–MAX3045 (EN, EN, EN_) to defined logic lev- els. Leakage currents from these high impedance dri- vers, of as much as 10µA, could cause the enable inputs of the MAX3040–MAX3045 to drift high or low. Additionally, parasitic capacitance of the circuit board could cause capacitive coupling of the enable inputs to either GND or VCC. These factors could cause the enable inputs of the MAX3040–MAX3045 to drift to lev- els that may enable the transmitter outputs (Y_ and Z_). To avoid this problem, the hot-swap input provides a method of holding the enable inputs of the MAX3040–MAX3045 in the disabled state as VCC ramps up. This hot-swap input is able to overcome the leakage currents and parasitic capacitances that may pull the enable inputs to the enabled state. Hot-Swap Input Circuitry In the MAX3040–MAX3045 the enable inputs feature hot-swap capability. At the input there are two NMOS devices, Q1 and Q2 (Figure 9). When VCC is ramping up from 0, an internal 10µs timer turns on Q2 and sets the SR latch, which also turns on Q1. Transistors Q2, a 700µA current sink, and Q1, an 85µA current sink, pull EN to GND through a 5.6k Ω resistor. Q2 is designed to pull the EN input to the disabled state against an exter- nal parasitic capacitance of up to 100pF that is trying to enable the EN input. After 10µs, the timer turns Q2 off and Q1 remains on, holding the EN input low against three-state output leakages that might enable EN. Q1 remains on until an external source overcomes the U = HIGH-VOLTAGE SOURCE RC = CHARGING RESISTOR CE = ENERGY STORAGE CAPACITOR RS = PULSE DURATION SHAPING RESISTOR RM = IMPEDANCE MATCHING RESISTOR CD = DC BLOCKING CAPACITOR SPARK GAP U RC RS RM CD CE 50 Ω COAXIAL OUTPUT Figure 7. Simplified Circuit Diagram of a Fast Transient/Burst Generator REPETITION PERIOD (DEPENDS ON THE TEST VOLTAGE LEVER, IN CONFORMITY WITH THE VALUES INDICATED IN 6.1.2). BURST BURST DURATION BURST PERIOD 300ms PULSE 15ms Figure 8. General Graph of a Fast Transient Burst |
Similar Part No. - MAX3040ESE |
|
Similar Description - MAX3040ESE |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |