PRODUCT SPECIFICATION

nRF401 Single Chip RF Transceiver

Nordic VLSI ASA -

Vestre Rosten 81, N-7075 Tiller, Norway

-

Phone +4772898900

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Fax +4772898989

Revision: 1.5

Page 8 of 18

May 2000

An additional notch filter (L and C) at the 50

Ω RF input/output may be necessary

dependent on the application requirements (see application note nAN400-05).

A single ended antenna may also be connected to nRF401 using an 8:1 impedance RF

transformer. The RF transformer must have a centre tap at the primary side for VDD

supply.

RF output power

The external bias resistor R3 connected between the RF_PWR pin and VSS sets the

output power. The RF output power may be set to levels up to +10dBm. In Figure 8

the output power is plotted for power levels down to, but not limited to, -8.5dBm for a

differential load of 400

Ω. DC power supply current versus external bias resistor value

is shown in Figure 9.

Figure 8. RF output power vs. external power setting resistor (R3) for nRF401.

Figure 9. Total chip current consumption vs. external power setting resistor (R3) for

nRF401.

Total Chip Current

22

27

33

39

47

56

68

82

100

120

150

180

0,0

5,0

10,0

15,0

20,0

25,0

30,0

0

20

40

60

80

100

120

140

160

180

200

Resistor Value [k

Ω

Ω ]

RF Output Power

22

27

33

39

47

56

68

82

100

120

150

180

-10

-8

-6

-4

-2

0

2

4

6

8

10

0

20

40

60

80

100

120

140

160

180

200

Resistor Value [k

Ω

Ω]