Datasheet
Table Of Contents
- 1.0 Introduction
- 2.0 Pin Description and Configuration
- 3.0 Functional Description
- 3.1 10BASE-T/100BASE-TX Transceiver
- 3.2 RMII Interface
- 3.3 Back-to-Back Mode – 100 Mbps Copper Repeater
- 3.4 MII Management (MIIM) Interface
- 3.5 Interrupt (INTRP)
- 3.6 HP Auto MDI/MDI-X
- 3.7 Loopback Mode
- 3.8 LinkMD® Cable Diagnostic
- 3.9 NAND Tree Support
- 3.10 Power Management
- 3.11 Reference Circuit for Power and Ground Connections
- 3.12 Typical Current/Power Consumption
- 4.0 Register Descriptions
- 5.0 Operational Characteristics
- 6.0 Electrical Characteristics
- 7.0 Timing Diagrams
- 8.0 Reset Circuit
- 9.0 Reference Circuits — LED Strap-In Pins
- 10.0 Reference Clock - Connection and Selection
- 11.0 Magnetic - Connection and Selection
- 12.0 Package Outline
2016 Microchip Technology Inc. DS00002199A-page 43
KSZ8081RNA/RND
9.0 REFERENCE CIRCUITS — LED STRAP-IN PINS
The pull-up, float, and pull-down reference circuits for the LED0/ANEN_SPEED strapping pin are shown in Figure 9-1
for 3.3V and 2.5V V
DDIO
.
FIGURE 9-1: REFERENCE CIRCUITS FOR LED STRAPPING PINS
For 1.8V V
DDIO
, LED indication support is not recommended due to the low voltage. Without the LED indicator, the
ANEN_SPEED strapping pin is functional with a 4.7 k pull-up to 1.8V V
DDIO
or float for a value of ‘1’, and with a 1.0 k
pull-down to ground for a value of ‘0’.
If using RJ45 jacks with integrated LEDs and 1.8V V
DDIO
, a level shifting is required from LED 3.3V to 1.8V. For example,
use a bipolar transistor or a level shift device.
LED0 PIN
220
4.7k
PULL-UP
KSZ8081RNA/RND
VDDIO = 3.3V, 2.5V
LED0 PIN
220
FLOAT
KSZ8081RNA/RND
VDDIO = 3.3V, 2.5V
LED0 PIN
220
PULL-DOWN
KSZ8081RNA/RND
VDDIO = 3.3V, 2.5V
1k