Datasheet

Micrel, Inc.
KSZ8081MNX/KSZ8081RNB
August
19, 2015 39
Revision 1.4
Typical Current/Power Consumption
Table 10, Table 11, and Table 12 show typical values for current consumption by the transceiver (VDDA_3.3) and digital
I/O (VDDIO) power pins and typical values for power consumption by the KSZ8081MNX/RNB device for the indicated
nominal operating voltages. These current and power consumption values include the transmit driver current and on-chip
regulator current for the 1.2V core.
Transceiver (3.3V), Digital I/Os (3.3V)
Table 10. Typical Current/Power Consumption (VDDA_3.3 = 3.3V, VDDIO = 3.3V)
Condition
3.3V Transceiver
(VDDA_3.3)
3.3V Digital I/Os
(VDDIO)
Total Chip Power
mA mA mW
100Base-TX Link-up (no traffic) 34 12 152
100Base-TX Full-duplex @ 100% utilization 34 13 155
10Base-T Link-up (no traffic) 14 11 82.5
10Base-T Full-duplex @ 100% utilization 30 11 135
Power-saving mode (Reg. 1Fh, Bit [10] = 1) 14 10 79.2
EDPD mode (Reg. 18h, Bit [11] = 0) 10 10 66.0
EDPD mode (Reg. 18h, Bit [11] = 0) and PLL off (Reg. 10h,
Bit [4] = 1)
3.77 1.54 17.5
Software power-down mode (Reg. 0h, Bit [11] =1) 2.59 1.51 13.5
Software power-down mode (Reg. 0h, Bit [11] =1) and slow-
oscillator mode (Reg. 11h, Bit [5] =1)
1.36 0.45 5.97
Transceiver (3.3V), Digital I/Os (2.5V)
Table 11. Typical Current/Power Consumption (VDDA_3.3 = 3.3V, VDDIO = 2.5V)
Condition
3.3V Transceiver
(VDDA_3.3)
2.5V Digital I/Os
(VDDIO)
Total Chip Power
mA mA mW
100Base-TX Link-up (no traffic) 34 11 140
100Base-TX Full-duplex @ 100% utilization 34 12 142
10Base-T Link-up (no traffic) 15 10 74.5
10Base-T Full-duplex @ 100% utilization 27 10 114
Power-saving mode (Reg. 1Fh, Bit [10] = 1) 15 10 74.5
EDPD mode (Reg. 18h, Bit [11] = 0) 11 10 61.3
EDPD mode (Reg. 18h, Bit [11] = 0) and
PLL off (Reg. 10h, Bit [4] = 1)
3.55 1.35 15.1
Software power-down mode (Reg. 0h, Bit [11] =1) 2.29 1.34 10.9
Software power-down mode (Reg. 0h, Bit [11] =1) and
slow-oscillator mode (Reg. 11h, Bit [5] =1)
1.15 0.29 4.52