
LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
Datasheet 
Document Number: 249241
Revision Number: 007
Revision Date: August 28, 2003
95
J15,
J16,
H17
185
186
187
LED5_1
LED5_2
LED5_3
OD, TS, SL, 
IP
Port 5 LED Drivers 1-3.
These pins drive LED indicators for Port 5. Each LED 
can display one of several available status conditions 
as selected by the LED Configuration Register (refer 
to 
Table 96 “LED Configuration Register (Address 20, 
Hex 14)” on page 213
 for details).
H15,
H16,
G17
189
190
191
LED6_1
LED6_2
LED6_3
OD, TS, SL, 
IP
Port 6 LED Drivers 1-3.
These pins drive LED indicators for Port 6. Each LED 
can display one of several available status conditions 
as selected by the LED Configuration Register (refer 
to 
Table 96 “LED Configuration Register (Address 20, 
Hex 14)” on page 213
 for details).
G15,
F17,
F16
192
193
194
LED7_1
LED7_2
LED7_3
OD, TS, SL, 
IP
Port 7 LED Drivers 1-3.
These pins drive LED indicators for Port 7. Each LED 
can display one of several available status conditions 
as selected by the LED Configuration Register (refer 
to 
Table 96 “LED Configuration Register (Address 20, 
Hex 14)” on page 213
 for details).
Table 34. Intel
 LXT9785/LXT9785E Power Supply Signal Descriptions – BGA23 (Sheet 1 of 2)
Ball/Pin Designation
Symbol
Type
Signal Description
BGA23
PQFP
G13, J14,
F5, J5
65, 78, 184, 
196
VCCD
-
Digital Power Supply - Core. 
+2.5 V supply for core digital circuits.
A2, A8,
C1, C11,
D14
18, 29, 47, 
56, 208
VCCIO
-
Digital Power Supply - I/O Ring. 
+2.5/3.3 V supply for digital I/O circuits. The digital 
input circuits running off of this rail, having a TTL-level 
threshold and over-voltage protection, may be 
interfaced with 3.3/5.0 V, when the IO supply is 3.3 V, 
and 2.5/3.3/5.0 V when 2.5 V.
L13, L5
98, 164
VCCPECL
-
Digital Power Supply - PECL Signal Detect Inputs.
+2.5/3.3 V supply for PECL Signal Detect input 
circuits. If Fiber Mode is not used, tie these pins to 
GNDPECL to save power.
N13, P4,
P7, P8,
P9, P10, 
P11, P12
103, 116, 
117, 130, 
131, 144, 
145, 158
VCCR
-
Analog Power Supply - Receive.
+2.5 V supply for all analog receive circuits.
1. Type Column Coding: I = Input, O = Output, OD = Open Drain output, ST = Schmitt Triggered input, TS = 
Three-State-able output, SL = Slew-rate Limited output, IP = weak Internal Pull-up, ID = weak Internal pull-
Down.
Table 33. Intel
 LXT9785/LXT9785E LED Signal Descriptions – BGA23 (Sheet 2 of 2)
 Ball/Pin 
Designation
Symbol
Type
1
Signal Description
2,3
BGA23
PQFP
1. Type Column Coding: I = Input, O = Output, OD = Open Drain output, ST = Schmitt Triggered input, TS = 
Three-State-able output, SL = Slew-rate Limited output, IP = weak Internal Pull-up, ID = weak Internal pull-
Down.
2. The IP/ID resistors are disabled during H/W Power-Down mode.   If a pin is an output or an I/O, the IP/ID 
resistors are also disabled when the output is enabled.
3. The LED outputs are three-stated in H/W Power-Down mode and during H/W reset.
4.