- 鎮ㄧ従(xi脿n)鍦ㄧ殑浣嶇疆锛�璨疯常IC缍�(w菐ng) > PDF鐩寗10015 > LTC1544IG#TR (Linear Technology)IC TXRX SFTWR SEL DTE/DCE 28SSOP PDF璩囨枡涓嬭級
鍙冩暩(sh霉)璩囨枡
| 鍨嬭櫉锛� | LTC1544IG#TR |
| 寤犲晢锛� | Linear Technology |
| 鏂囦欢闋佹暩(sh霉)锛� | 5/20闋� |
| 鏂囦欢澶�?銆�?/td> | 0K |
| 鎻忚堪锛� | IC TXRX SFTWR SEL DTE/DCE 28SSOP |
| 妯欐簴鍖呰锛� | 2,000 |
| 椤炲瀷锛� | 鏀剁櫦(f膩)鍣� |
| 椹�(q奴)鍕曞櫒/鎺ユ敹鍣ㄦ暩(sh霉)锛� | 4/4 |
| 闆绘簮闆诲锛� | 4.75 V ~ 5.25 V |
| 瀹夎椤炲瀷锛� | 琛ㄩ潰璨艰 |
| 灏佽/澶栨锛� | 28-SSOP锛�0.209"锛�5.30mm 瀵級 |
| 渚涙噳鍟嗚ō鍌欏皝瑁濓細 | 28-SSOP |
| 鍖呰锛� | 甯跺嵎 (TR) |
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13
LTC1544
Charge Pump
The LTC1543 uses an internal capacitive charge pump to
generate VDD and VEE as shown in Figure 21. A voltage
doubler generates about 8V on VDD and a voltage inverter
generates about 鈥� 7.5V for VEE. Four 1F surface mounted
tantalum or ceramic capacitors are required for C1, C2, C3
and C4. The VEE capacitor C5 should be a minimum of
3.3
F.Allcapacitorsare16Vandshouldbeplacedasclose
as possible to the LTC1543 to reduce EMI.
The generator differential impedance must be 50
to
150
and the impedance between shorted terminals (A
and B) and ground C must be 150
卤15. For the
generator termination, switches S1 and S2 are both on and
the top side of the center resistor is brought out to a pin so
it can be bypassed with an external capacitor to reduce
common mode noise as shown in Figure 20.
Figure 20. V.35 Driver Using the LTC1344A
V.35 DRIVER
A
B
C
51.5
S2
ON
S1
ON
1544 F20
51.5
LTC1344A
124
C1
100pF
28
27
26
25
1544 F21
3
2
1
4
C3
1
F
C4
1
F
5V
C1
1
F
C2
1
F
C5
3.3
F
LTC1543
VDD
C1+
C1鈥�
VCC
C2+
C2鈥�
VEE
GND
+
Figure 21. Charge Pump
Any mismatch in the driver rise and fall times or skew in
the driver propagation delays will force current through
the center termination resistor to ground, causing a high
frequency common mode spike on the A and B terminals.
The common mode spike can cause EMI problems that are
reduced by capacitor C1 which shunts much of the com-
mon mode energy to ground rather than down the cable.
No-Cable Mode
The no-cable mode (M0 = M1 = M2 = 1) is intended for the
case when the cable is disconnected from the connector.
The charge pump, bias circuitry, drivers and receivers are
turned off, the driver outputs are forced into a high
impedance state, and the supply current drops to less than
200
A.
Receiver Fail-Safe
All LTC1543/LTC1544 receivers feature fail-safe opera-
tion in all modes. If the receiver inputs are left floating or
shorted together by a termination resistor, the receiver
output will always be forced to a logic high.
DTE vs DCE Operation
The DCE/DTE pin acts as an enable for Driver 3/Receiver
1 in the LTC1543, and Driver 3/Receiver 1 and Driver 4/
Receiver 4 in the LTC1544. The INVERT pin in the LTC1544
allows the Driver 4/Receiver 4 enable to be high or low true
polarity.
APPLICATIONS INFORMATION
WU
U
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| MS27466T15B35SB | CONN RCPT 37POS WALL MNT W/SCKT |
| IDT72V3640L15PFI8 | IC FIFO SS 1024X36 15NS 128-TQFP |
鐩搁棞浠ｇ悊鍟�/鎶€琛撳弮鏁�(sh霉) |
鍙冩暩(sh霉)鎻忚堪 |
|---|---|
| LTC1545CG | 鍔熻兘鎻忚堪:IC TXRX SOFTWARE SELECTBL 36SSOP RoHS:鍚� 椤炲垾:闆嗘垚闆昏矾 (IC) >> 鎺ュ彛 - 椹�(q奴)鍕曞櫒锛屾帴鏀跺櫒锛屾敹鐧�(f膩)鍣� 绯诲垪:- 妯欐簴鍖呰:250 绯诲垪:- 椤炲瀷:鏀剁櫦(f膩)鍣� 椹�(q奴)鍕曞櫒/鎺ユ敹鍣ㄦ暩(sh霉):2/2 瑕�(gu墨)绋�:RS232 闆绘簮闆诲:3 V ~ 5.5 V 瀹夎椤炲瀷:琛ㄩ潰璨艰 灏佽/澶栨:16-TSSOP锛�0.173"锛�4.40mm 瀵級 渚涙噳鍟嗚ō鍌欏皝瑁�:16-TSSOP 鍖呰:甯跺嵎 (TR) |
| LTC1545CG#PBF | 鍔熻兘鎻忚堪:IC TXRX SOFTWARE SELECT 36-SSOP RoHS:鏄� 椤炲垾:闆嗘垚闆昏矾 (IC) >> 鎺ュ彛 - 椹�(q奴)鍕曞櫒锛屾帴鏀跺櫒锛屾敹鐧�(f膩)鍣� 绯诲垪:- 妯欐簴鍖呰:250 绯诲垪:- 椤炲瀷:鏀剁櫦(f膩)鍣� 椹�(q奴)鍕曞櫒/鎺ユ敹鍣ㄦ暩(sh霉):2/2 瑕�(gu墨)绋�:RS232 闆绘簮闆诲:3 V ~ 5.5 V 瀹夎椤炲瀷:琛ㄩ潰璨艰 灏佽/澶栨:16-TSSOP锛�0.173"锛�4.40mm 瀵級 渚涙噳鍟嗚ō鍌欏皝瑁�:16-TSSOP 鍖呰:甯跺嵎 (TR) |
| LTC1545CG#TR | 鍔熻兘鎻忚堪:IC TXRX SOFTWARE SELECTBL 36SSOP RoHS:鍚� 椤炲垾:闆嗘垚闆昏矾 (IC) >> 鎺ュ彛 - 椹�(q奴)鍕曞櫒锛屾帴鏀跺櫒锛屾敹鐧�(f膩)鍣� 绯诲垪:- 妯欐簴鍖呰:250 绯诲垪:- 椤炲瀷:鏀剁櫦(f膩)鍣� 椹�(q奴)鍕曞櫒/鎺ユ敹鍣ㄦ暩(sh霉):2/2 瑕�(gu墨)绋�:RS232 闆绘簮闆诲:3 V ~ 5.5 V 瀹夎椤炲瀷:琛ㄩ潰璨艰 灏佽/澶栨:16-TSSOP锛�0.173"锛�4.40mm 瀵級 渚涙噳鍟嗚ō鍌欏皝瑁�:16-TSSOP 鍖呰:甯跺嵎 (TR) |
| LTC1545CG#TRPBF | 鍔熻兘鎻忚堪:IC TXRX SOFTWARE SELECTBL 36SSOP RoHS:鏄� 椤炲垾:闆嗘垚闆昏矾 (IC) >> 鎺ュ彛 - 椹�(q奴)鍕曞櫒锛屾帴鏀跺櫒锛屾敹鐧�(f膩)鍣� 绯诲垪:- 妯欐簴鍖呰:250 绯诲垪:- 椤炲瀷:鏀剁櫦(f膩)鍣� 椹�(q奴)鍕曞櫒/鎺ユ敹鍣ㄦ暩(sh霉):2/2 瑕�(gu墨)绋�:RS232 闆绘簮闆诲:3 V ~ 5.5 V 瀹夎椤炲瀷:琛ㄩ潰璨艰 灏佽/澶栨:16-TSSOP锛�0.173"锛�4.40mm 瀵級 渚涙噳鍟嗚ō鍌欏皝瑁�:16-TSSOP 鍖呰:甯跺嵎 (TR) |
| LTC1545IG | 鍔熻兘鎻忚堪:IC TXRX SOFTWARE SELECTBL 36SSOP RoHS:鍚� 椤炲垾:闆嗘垚闆昏矾 (IC) >> 鎺ュ彛 - 椹�(q奴)鍕曞櫒锛屾帴鏀跺櫒锛屾敹鐧�(f膩)鍣� 绯诲垪:- 妯欐簴鍖呰:250 绯诲垪:- 椤炲瀷:鏀剁櫦(f膩)鍣� 椹�(q奴)鍕曞櫒/鎺ユ敹鍣ㄦ暩(sh霉):2/2 瑕�(gu墨)绋�:RS232 闆绘簮闆诲:3 V ~ 5.5 V 瀹夎椤炲瀷:琛ㄩ潰璨艰 灏佽/澶栨:16-TSSOP锛�0.173"锛�4.40mm 瀵級 渚涙噳鍟嗚ō鍌欏皝瑁�:16-TSSOP 鍖呰:甯跺嵎 (TR) |
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