nRF2401 Nordic VLSI, nRF2401 Datasheet
nRF2401
Available stocks
Related parts for nRF2401
nRF2401 Summary of contents
Page 1
... RF tested No need for external SAW filter World wide use nRF2401 is a single-chip radio transceiver for the world wide 2.4 - 2.5 GHz ISM band. The transceiver consists of a fully integrated frequency synthesizer, a power amplifier, a crystal oscillator and a modulator. Output power and frequency channels are easily programmable by use of the 3-wire serial interface ...
Page 2
... Decode CLK2 CRC Code/Decode DR1 FIFO In/Out DATA Data Channel 1 CLK1 GFSK 3-wire Filter interface CS Figure 1 nRF2401 with external components. Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 24 pin QFN 5x5 TM TM LNA Frequency Synthesiser - Phone +4772898900 Page 1.0 XC1 ...
Page 3
... DOUT2 DR1 7 CLK1 Figure 2. nRF2401 pin assignment (top view) for a QFN24 5x5 package. Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 Chip Enable Activates mode RX Data Ready at Data Channel 2 (ShockBurst™ only) Clock Output/Input for RX Data Channel 2 RX Data Channel 2 Chip Select Activates Configuration Mode RX Data Ready at Data Channel 1 (ShockBurst™ ...
Page 4
... De-embedded Antenna load impedance = 400 5) De-embedded Antenna load impedance = 400 . Effective data rate 250kbps or 1Mbps. 6) De-embedded Antenna load impedance = 400 . Effective data rate 10kbps. 7) Current if 4 MHz crystal is used. Table 4 nRF2401 RF specifications Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1 40º 85º ...
Page 5
... PRODUCT SPECIFICATION nRF2401 uses the QFN 24LD 5x5 package. Dimensions are in mm. QFN24 0.8 0.0 (5x5 mm) 1 0.05 Figure 3 nRF2401 package outline. Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 0.75 0.25 0.3 5 BSC 5 BSC 1 0.35 - Phone +4772898900 Page 3.47 3.47 0.35 0.65 BSC 3.57 3.57 0.4 3.67 3.67 0.45 - Fax +4772898989 March 2003 ...
Page 6
... VDD + 0. =85 C).............................. 90mW D A Operating Temperature… Storage Temperature….… 125 C Electrostatic Sensitive Device Observe Precaution for handling. Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 - Phone +4772898900 Page Fax +4772898989 March 2003 ...
Page 7
... Data Ready GFSK Gaussian Frequency Shift Keying ISM Industrial-Scientific-Medical MCU Micro controller OD Overdrive PWR_DWN Power Down PWR_UP Power Up RX Receive ST_BY Standby TX Transmit Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 Table 5 Glossary - Phone +4772898900 Page Fax +4772898989 March 2003 ...
Page 8
... Active (RX/TX) Configuration Stand by Power down Table 6 nRF2401 main modes For a complete overview of the nRF2401 I/O pins in the different modes please refer to Table 7. The nRF2401 has two active (RX/TX) modes: ShockBurst™ Direct Mode The device functionality in these modes is decided by the content of a configuration word ...
Page 9
... Lower system cost (facilitates use of less expensive micro controller) Greatly reduced risk of ‘on-air’ collisions due to short transmission time The nRF2401 can be programmed using a simple 3-wire interface where the data rate is decided by the speed of the micro controller. By allowing the digital part of the application to run at low speed while maximizing the data rate on the RF link, the nRF ShockBurst™ ...
Page 10
... When the application MCU has data to send, set CE high. This activates RF2401 on-board data processing. 2. The address of the receiving node (RX address) and payload data is clocked into the nRF2401. The application protocol or MCU sets the speed <1Mbps (ex: 10kbps). 3. MCU sets CE low, this activates a nRF2401 ShockBurst™ transmission. ...
Page 11
... Clocks out Payload NO nRF2401 Register Empty? YES nRF2401 Sets Data Ready (DR1/2) low Figure 7 Flow Chart ShockBurst™ Receive of nRF2401 Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 Data content of registers: Pre- ADDR PAYLOAD amble ADDR PAYLOAD ...
Page 12
... Once the nRF2401 is configured and powered up (CE high) in direct RX mode, DATA will start to toggle due to noise present on the air. 2. CLK1 will also start to toggle as nRF2401 is trying to lock on to the incoming data stream. 3. Once a valid preamble arrives, CLK1 and DATA will lock on to the incoming signal and the RF package will appear at the DATA pin with the same speed transmitted ...
Page 13
... The nRF2401 must be programmed to receive at the frequency of data channel 1. No time multiplexing is used in nRF2401 to fulfil this function. In direct mode the MCU must be able to handle two simultaneously incoming data packets not multiplexing between the two data channels. In ShockBurst™ ...
Page 14
... PRODUCT SPECIFICATION In configuration mode a configuration word bytes is downloaded to nRF2401. This is done through a simple 3-wire interface (CS, CLK1 and DATA). For more information on configuration please refer to the nRF2401 Device configuration chapter on page16. Stand by mode is used to minimize average current consumption while maintaining short start up times ...
Page 15
... CLK DATA Set to 0 DATA In Out 0 CLK DATA In Out CLK DATA 0 Out Out 0 CLK DATA 0 Out Out CLK DATA Table 7 Pin configuration of nRF2401. - Phone +4772898900 - Fax +4772898989 March 2003 CLK CLK CLK ...
Page 16
... PRODUCT SPECIFICATION All configuration of the nRF2401 is done via a 3-wire interface to a single configuration register. The configuration word can bytes long for ShockBurst™ use and bytes long for direct mode. The configuration word in ShockBurst™ enables the nRF2401 to handle the RF protocol ...
Page 17
... On the falling edge of CS, the nRF2401 updates the number of bits actually shifted in during the last configuration. Ex: If the nRF2401 configured for 2 channel RX in ShockBurst™, a total of 120 bits must be shifted in during the first configuration after VDD is applied. Once the wanted protocol, modus and RF channel are set, only one bit (RXEN) is shifted in to switch between RX and TX ...
Page 18
... PRODUCT SPECIFICATION The following describes the function of the 144 bits (bit 143 = MSB) that is used to configure the nRF2401. General Device Configuration: bit[15:0] ShockBurst™ Configuration: bit[119:0] Test Configuration: bit[143:120] MSB TEST D143 D142 D141 D140 D139 Reserved for testing ...
Page 19
... ADDR_W: length of RX address set in configuration word B[23:18] CRC: check sum bits set in configuration word B[17] PRE: preamble bits are automatically included Shorter address and CRC leaves more room for payload data in each package. Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 ...
Page 20
... NOTE: Maximum number of address bits bytes). Values over 40 in ADDR_W are not valid. Bit 17: CRC_L: CRC length to be calculated by nRF2401 in ShockBurst™. Logic 0: 8 bit CRC Logic 1: 16 bit CRC Bit: 16: CRC_EN: Enables on-chip CRC generation (TX) and verification (RX). ...
Page 21
... RX2_EN: Logic 0: One channel receive Logic 1: Two channels receive NOTE: In two channels receive, the nRF2401 receives on two, separate frequency channels simultaneously. The frequency of receive channel 1 is set in the configuration word B[7-1], receive channel 2 is always 8 channels (8 MHz) above receive channel 1. Bit 14: Communication Mode: Logic 0: nRF2401 operates in direct mode ...
Page 22
... Table 16 RF output power setting Table 17 Frequency channel + setting. Bit 7 – 1: RF_CH#: Sets the frequency channel the nRF2401 operates on. The channel frequency in WUDQVPLW is given by: 2400 5) RF_CH #: between 2400MHz and 2527MHz may be set. The channel frequency in GDWD FKDQQHO is given by: ...
Page 23
... ADDRESS Figure 11 Data Package Diagram The data packet for both ShockBurst™ mode and direct mode communication is divided into 4 sections. These are: Table 18 Data package description Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 PAYLOAD The preamble field is required in ShockBurst™ and Direct modes Preamble is 8 (or 4) bits in length and is dependent of the first data bit in direct mode ...
Page 24
... Minimum input clock high Set-up of data in Direct Mode Minimum clock high in Direct Mode Minimum clock low in Direct Mode Table 19 Switching times for nRF2401 When the nRF2401 is in power down it must always settle in stand-by (Tpd2sby) before it can enter configuration or one of the active modes. PWR_UP CS CE ...
Page 25
... If the device is configured one can go directly from power down to the wanted active mode. CE and CS may not be high at the same time. Setting one or the other decides whether configuration or active mode is entered. Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 ...
Page 26
... When one or more of the bits in the configuration word needs to be changed the following timing apply. PWR_UP CS CE CLK1 DATA Figure 14 Timing diagram for configuration of nRF2401 If configuration mode is entered from power down, CS can be set high after Tpd2sby as shown in Figure 12. Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 ‡ ...
Page 27
... CS CE CLK1 DATA ANT1/ANT2 Td Figure 15 Timing of ShockBurst™ The package length and the data rate give the delay Toa (time on air), as shown in the equation Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1 CLK1 DATA Phone +4772898900 Page ...
Page 28
... DOUT2 Td Figure 16 Timing of ShockBurst™ The CE may be kept high during downloading of data, but the cost is higher current consumption (18mA) and the benefit is no start-up time (200 s) after the DR1 goes low. Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1 ...
Page 29
... PWR_UP CS CE CLK1 DATA ANT1/ANT2 Td Figure 17 Timing of direct mode direct mode the input data will be sampled by nRF2401 and therefore no clock is needed. The clock must be stable at low level during transmission due to noise considerations. The exact delay T 194 / Nordic VLSI ASA ...
Page 30
... PWR_UP CS CE CLK1/2 DATA/DOUT2 ANT1/ANT2 Td DATA/DOUT2 Figure 18 Timing of direct mode RX Tsby2rx describes the delay from the positive edge the start detection of (demodulated) incoming data. Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 Tsby2rx CE T hdm CLK1/2 Tsdm - Phone +4772898900 ...
Page 31
... Lower load impedance (for instance 50 ) can be obtained by fitting a simple matching network Conditions: VDD = 3.0V, VSS = 0V, T Table 20 RF output power setting for the nRF2401. Tolerance includes initially accuracy and tolerance over temperature and aging. 4 12pF 8 12pF 12 12pF ...
Page 32
... Long power supply lines on the PCB should be avoided. All device grounds, VDD connections and VDD bypass capacitors must be connected as close as possible to the nRF2401 IC. For a PCB with a topside RF ground plane, the VSS pins should be connected directly to the ground plane. For a PCB with a bottom ground plane, the best technique is to have via holes as close as possible to the VSS pads ...
Page 33
... VDD C6 10nF PWR_UP CE DR2 CLK2 DOUT2 CS DR1 CLK1 DATA Figure 19 nRF2401 schematic for RF layouts with single end 50 antenna C1 Capacitor ceramic, 50V, NPO C2 Capacitor ceramic, 50V, NPO C3 Capacitor ceramic, 50V, NPO C4 Capacitor ceramic, 50V, X7R C5 Capacitor ceramic, 50V, X7R C6 Capacitor ceramic, 50V, X7R ...
Page 34
... A large number of via holes connect the top layer ground areas to the bottom layer ground plane. Top silk screen Top view Figure 20 nRF2401 RF layout with single ended connection to 50 antenna and 0603 Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1 ...
Page 35
... Nordic VLSI ASA for any damages resulting from such improper use or sale. Preliminary Product Specification: Revision Date: 27.03.2003. Datasheet order code: 270303-nRF2401. All rights reserved ®. Reproduction in whole or in part is prohibited without the prior written permission of the copyright holder. ...
Page 36
... PRODUCT SPECIFICATION Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 - Phone +4772898900 Page Fax +4772898989 March 2003 ...
Page 37
... PRODUCT SPECIFICATION Vestre Rosten 81, N-7075 Tiller, Norway Phone: + 00, Fax: + Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway Revision: 1.0 - Phone +4772898900 Page Fax +4772898989 March 2003 ...