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Part: ML4669IQ
Category:
Description: 10BASE-FL to 10BASE-T Converter
Company: Micro Linear
Datasheet: Download ML4669IQ datasheet File size : 5795 kB
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July 2000
ML4664*/ML4669* 10BASE-FL to 10BASE-T Converter
GENERAL DESCRIPTION
The fully pin-compatible ML4664/ML4669 pair provide conversion from 10BASE-T copper media to 10BASE-FL fiber media in a single chip. They are compliant with Ethernet IEEE 802.3 10BASE-T and 10BASE-FL standards. The ML4664/69 uses a single 5V supply, and requires no crystal or clock. Their 10BASE-FL transmitter offers a current drive output that directly drives a fiber optic LED transmitter. Their receiver offers a highly stable fiber optic data quantizer capable of accepting input signals as low as 2mVP-P with a 55dB dynamic range. The 10BASE-T portion of the pair contains current driven transmitter outputs that offer superior performance because their switching is highly symmetric, resulting in lowered RFI noise and jitter. By changing one external resistor the pair easily interfaces to 100W unshielded twisted pair, 150W shielded twisted pair, or a range of other characteristic impedances. The ML4664 does not pass along disconnect information, while the ML4669 does. A loss of light at the optical inputs does not stop link pulses from being sent at the twisted pair transmitter in the ML4664, but in the ML4669 the link pulses stop. Also, a loss of link at the twisted pair inputs will not stop the optical transmitter from sending idle in the ML4664, but the ML4669 stops sending idle.
FEATURES
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Full duplex operation Five network status LED outputs Industrial temperature option
10BASE-FL FEATURES:
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Highly stable data quantizer with 55dB input dynamic range Input sensitivity as low as 2mVP-P Up to 100mA maximum current driven fiber optic LED output for accurate launch power (PLCC package)
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10BASE-T FEATURES:
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Current driven output for low RFI noise and low jitter Drives 100W unshielded or 150W shielded twisted pair Polarity detect status pin capable of driving an LED Automatic polarity correction On-chip link test with enable/disable option
* Some Packages Are Obsolete
BLOCK DIAGRAM
LTF LINK PULSE CHECK TPLED POLDIS IDLE GENERATOR RRSET RTSETOP
TPIN
2
RX SQUELCH TP
OP TX
OPOUT OPVCC
POLARITY CORRECT
LINK PULSE GENERATOR RX SQUELCH TP TPOUT 2 RTSETTP TP TX TxCAP0 TxCAP1 LMON
(LOW LIGHT)
THRESHOLD GENERATOR
QUANTIZER OPLED VDC CTIMER
2
OPIN
1
ML4664/ML4669
PIN CONFIGURATION
ML4664/ML4669 28-Pin PLCC (Q28)
CTIMER OPLED OPINP TPLED TPINP AVCC LTF
2
4 TPINN VCC TxCAP0 TxCAP1 GND TPOUTN TPOUTP 5 6 7 8 9 10 11
3
1 28 27 26 25 24 23 22 21 20 19 OPINN AGND VTHADJ VREF VDC GND OPOUT
12 13 14 15 16 17 18
VCC RRSET
POLDIS
LMON
TOP VIEW
ML4664/ML4669 32-Pin TQFP (H32-7)
CTIMER OPLED OPINP TPLED TPINP AVCC LTF NC
TPINN NC VCC TxCAP0 TxCAP1 GND TPOUTN TPOUTP
32 31 30 29 28 27 26 25 24 1 2 3 4 5 6 7 8 9 23 22 21 20 19 18 17 10 11 12 13 14 15 16
RTSETOP
OPVCC
RTSETP
OPINN AGND VTHADJ VREF VDC NC GND OPOUT
NC
POLDIS
RTSETP
VCC
RRSET
RTSETOP
LMON
TOP VIEW
2
OPVCC
ML4664/ML4669
PIN DESCRIPTION (Pin Number in Parentheses is for TQFP Version)
PIN NAME FUNCTION PIN NAME FUNCTION
1(29)
CTIMER
A capacitor from this pin to VCC determines the Link Monitor response time. Link Test Fail. Active high. Normally this pin is low, indicating that the link is operational. If the link goes down resulting from the absence of link pulses or frames being received, the chip will go into the Link Test Fail state and bring LTF high. When the ML4664 is in the link test fail state, the optical and twisted pair transmitters are disabled from sending data. However, the optical transmitter does send an idle signal, and link pulses are sent at the twisted pair transmitter. When the ML4669 is in link test fail state, the optical and twisted pair transmitters are disabled from sending data. Also, the optical transmitter will not send an idle signal. However, link pulses may be sent at the twisted pair transmitter, depending on the optical inputs. See Table 1. This pin may be grounded to disable Link Test. In this mode no link pulses are sent and the link will not fail if no link pulses are received. If this pin is not used as an LED driver, and is not grounded, a 2kW 5% resistor should be connected between this pin and VCC.
7(4) 8(5)
TxCAP0 TxCAP1
2(30)
LTF
An external capacitor of 680pF is tied between these two pins to set the pulse width for the preequalization on the twisted pair transmitter. If these two pins are shorted together, no pre- equalization occurs. If the ML4664/ML4669 is driving only a short cable, or board traces, these pins may be shorted. Ground reference
9(6) GND 20(18) 10(7) 11(8)
TPOUTN Pre-equalized differential balanced TPOUTP current driven output. These outputs are connected to a balanced transmit output filter which drives the twisted pair cable through pulse transformers. The output current is set with an external resistor connected to RTSET allowing the chip to drive 100W unshielded , 150W shielded twisted pair cables or a range of other characteristic impedances. Receive Polarity status. Active low LED Driver, open collector output. Indicates the polarity of the receive twisted pair regardless of auto polarity correction. When low, receive polarity is reversed. When high, receive polarity is correct. This pin may be grounded to disable the polarity circuit. If this pin is not used as an LED driver, and is not grounded, a 2kW, 5% resistor should be connected between this pin and VCC.
12(10) POLDIS
3(31)
TPLED
Indicates that reception is taking place on the TPINP, TPINN pair. Active low LED driver, open collector. It is extended 16ms for visibility. Optionally, this pin may be grounded to disable the optical output. If this pin is not used as an LED driver and is not grounded, a 2kW, 5% resistor should be connected between TPLED and VCC. Twisted Pair receive data input. When this signal exceeds the receive squelch requirements the receive data is buffered and sent to the Rx± outputs. 5V input
13(11) RTSETTP When using 100W unshielded twisted pair, a 220W resistor is tied between this pin and VCC. When using 150W shielded twisted pair, a 330W resistor is tied between this pin and VCC. 15(13) RRSET A 1% 61.9kW resistor tied from this pin to VCC is used for internal biasing.
4(32) 5(1)
TPINP TPINN
16(14) RTSETOP Sets the current driven output of the transmitter. A 115W resistor should be tied between this pin and VCC.
6(3) VCC 14(12)
3
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