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1
TM
FN4816.2
HFA3861B
Direct Sequence Spread Spectrum
Baseband Processor
The Intersil HFA3861B Direct
Sequence Spread Spectrum (DSSS)
baseband processor is part of the
PRISM 2.4GHz WLAN Chip Set,
and contains all the functions necessary for a full or half
duplex packet baseband transceiver.
The HFA3861B has on-board A/D's and D/A for analog I and
Q inputs and outputs, for which the HFA3783 IF QMODEM is
recommended. Differential phase shift keying modulation
schemes DBPSK and DQPSK, with data scrambling
capability, are available along with Complementary Code
Keying to provide a variety of data rates. Built-in flexibility
allows the HFA3861B to be configured through a general
purpose control bus, for a range of applications. Both
Receive and Transmit AGC functions with 7-bit AGC control
obtain maximum performance in the analog portions of the
transceiver. The HFA3861B is housed in a thin plastic quad
flat package (TQFP) suitable for PCMCIA board
applications.
Pinout
Features
Complete DSSS Baseband Processor
Processing Gain . . . . . . . . . . . . . . . . . . . . FCC Compliant
Programmable Data Rate. . . . . . . . 1, 2, 5.5, and 11Mbps
Ultra Small Package . . . . . . . . . . . . . . . . . . . . . 10 x 10mm
Single Supply Operation (44MHz Max) . . . . . 2.7V to 3.6V
Modulation Methods . . . . . . . . DBPSK, DQPSK, and CCK
Supports Full or Half Duplex Operations
On-Chip A/D and D/A Converters for I/Q Data (6-Bit,
22MSPS), AGC, and Adaptive Power Control (7-Bit)
Targeted for Multipath Delay Spreads ~50ns
Supports Short Preamble Acquisition
Supports Antenna Diversity
Applications
Enterprise WLAN Systems
Systems Targeting IEEE 802.11 Standard
DSSS PCMCIA Wireless Transceiver
Spread Spectrum WLAN RF Modems
TDMA Packet Protocol Radios
Part 15 Compliant Radio Links
Portable PDA/Notebook Computer
Wireless Digital Audio, Video, Multimedia
PCN/Wireless PBX
Wireless Bridges
Simplified Block Diagram
Ordering Information
PART NUMBER
TEMP.
RANGE (
o
C)
PACKAGE
PKG. NO.
HFA3861BIN
-40 to 85
64 Ld TQFP
Q64.10x10
HFA3861BIN96
-40 to 85
Tape and Reel
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
TEST4
TEST3
TEST2
TEST1
TEST0
GNDd
MCLK
NC
ANT-SEL
ANT-SEL
RX-RF_AGC
V
DDD
GNDd
TX_IF_AGC
RX_IF_AGC
COMPCAP1
GNDd
V
DDD
SD
SCLK
R/W
CS
GNDd
V
DDD
GNDa
RX_I+
RX_I-
V
DDA
RX_Q+
RX_Q-
GNDa
V
REF
SDI
R
E
S
E
T
TX_PE
RX_PE
CCA
TX_RD
Y
TXD
V
DDD
GNDd
TXCLK
MD_RD
Y
RXD
RXCLK
TEST7
TEST6
TEST5
V
DD
A
TX_A
GC_IN
RX-IF_DET
GNDa
I
REF
V
DD
A
TX_I+
TX_I-
GNDa
COMPCAP2
COMPRES2
GNDa
TX_Q+
TX_Q-
V
DD
A
COMPRES1
6
7
6
6
6
6
7
1
1
ANT_SEL
RX_RF_AGC
RX_IF_DET
THRESH.
DETECT
IF
DAC
I ADC
Q ADC
44MHz MCLK
HFA 3861B BBP
TX
ALC
TX
DAC
TX
ADC
I DAC
Q DAC
MOD
I/O
DEMOD
AGC
CTL
V
REF
RX_Q
RX_I
RX_IF_AGC
TX_Q
TX_I
TX_IF_AGC
TX_AGC_IN
DATA I/O
Data Sheet
February 2002
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
|
Intersil (and design) is a trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2002. All Rights Reserved
PRISM is a registered trademark of Intersil Corporation. PRISM and design is a trademark of Intersil Corporation.
2
Typical Application Diagram
For additional information on the PRISM chip set, visit our web site
www.intersil.com or call 1-888-INTERSIL or 321-724-7143.
TYPICAL TRANSCEIVER APPLICATION CIRCUIT USING THE HFA3861B
6
7
6
6
6
6
7
1
1
IF
DAC
I ADC
Q ADC
44MHz MCLK
HFA3861B BBP
TX
ALC
TX
DAC
TX
ADC
I DAC
Q DAC
MOD
I/O
DEMOD
AGC
CTL
IF
RF
ADC
RF
DAC
REF IN
LO
I/O LO
PLL
HFA3783 QUAD IF
REF IN
REF IN
RF
LO
PLL
HFA3963
RFPA
DIFFERENTIAL SIGNALS
REFOUT
EXTERNAL
MEMORY
RADIO
DATA
INTERFACE
RADIO
CONTROL
PORTS
GP SERIAL
PORTS
WEP
ENGINE
CPU
16-BIT
PIPELINED
CONTROL
PROCESSOR
HOST
INTERFACE
LOGIC
MEMORY
ACCESS
ARBITER
HOSTPC
INTERF
A
C
E
HFA3841
MAC
AntSel
T/Rsw
(FILE# 4816)
(FILE# 4633)
HFA3683A RF/IF
CONV (FILE# 4634)
(FILE# 4635)
(FILE# 4661)
HF
A3861B
3
Pin Descriptions
NAME
PIN TYPE
I/O
DESCRIPTION
V
DDA
(Analog)
12, 17, 22,
31
Power
DC power supply 2.7V - 3.6V (Not Hard wired Together On Chip).
V
DDD
(Digital)
2, 8, 37, 57
Power
DC power supply 2.7 - 3.6V.
GNDa
(Analog)
9, 15, 20,
25, 28,
Ground
DC power supply 2.7 - 3.6V, ground (Not Hard wired Together On Chip).
GNDd (Digital) 1, 7, 36, 43,
56
Ground
DC power supply 2.7 - 3.6V, ground.
V
REF
16
I
Voltage reference for A/D's and D/A's.
I
REF
21
I
Current reference for internal ADC and DAC devices. Requires a 12k
resistor to ground.
RXI
, +/-
10/11
I
Analog input to the internal 6-bit A/D of the In-phase received data. Balanced differential 10+/11-.
RXQ
, +/-
13/14
I
Analog input to the internal 6-bit A/D of the Quadrature received data. Balanced differential 13+/14-.
ANTSEL
39
O
The antenna select signal changes state as the receiver switches from antenna to antenna during the
acquisition process in the antenna diversity mode. This is a complement for ANTSEL (pin 40) for
differential drive of antenna switches.
ANTSEL
40
O
The antenna select signal changes state as the receiver switches from antenna to antenna during the
acquisition process in the antenna diversity mode. This is a complement for ANTSEL (pin 39) for
differential drive of antenna switches.
RX_IF_DET
19
I
Analog input to the receive power A/D converter for AGC control.
RX_IF_AGC
34
O
Analog drive to the IF AGC control.
RX_RF_AGC
38
O
Drive to the RF AGC stage attenuator. CMOS digital.
TX_AGC_IN
18
I
Input to the transmit power A/D converter for transmit AGC control.
TX_IF_AGC
35
O
Analog drive to the transmit IF power control.
TX_PE
62
I
When active, the transmitter is configured to be operational, otherwise the transmitter is in standby
mode. TX_PE is an input from the external Media Access Controller (MAC) or network processor to
the HFA3861B. The rising edge of TX_PE will start the internal transmit state machine and the falling
edge will initiate shut down of the state machine. TX_PE envelopes the transmit data except for the
last bit. The transmitter will continue to run for 4
s after TX_PE goes inactive to allow the PA to shut
down gracefully.
TXD
58
I
TXD is an input, used to transfer MAC Payload Data Unit (MPDU) data from the MAC or network
processor to the HFA3861B. The data is received serially with the LSB first. The data is clocked in the
HFA3861B at the rising edge of TXCLK.
TXCLK
55
O
TXCLK is a clock output used to receive the data on the TXD from the MAC or network processor to
the HFA3861B, synchronously. Transmit data on the TXD bus is clocked into the HFA3861B on the
rising edge. The clocking edge is also programmable to be on either phase of the clock. The rate of
the clock will be dependent upon the data rate that is programmed in the signalling field of the header.
TX_RDY
59
O
TX_RDY is an output to the external network processor indicating that Preamble and Header
information has been generated and that the HFA3861B is ready to receive the data packet from the
network processor over the TXD serial bus.
CCA
60
O
Clear Channel Assessment (CCA) is an output used to signal that the channel is clear to transmit. The
CCA may be configured to one of four possible algorithms. The CCA algorithm and its features are
described elsewhere in the data sheet.
Logic 0 = Channel is clear to transmit.
Logic 1 = Channel is NOT clear to transmit (busy).
This polarity is programmable and can be inverted.
RXD
53
O
RXD is an output to the external network processor transferring demodulated Header information and
data in a serial format. The data is sent serially with the LSB first. The data is frame aligned with
MD_RDY.
RXCLK
52
O
RXCLK is the bit clock output. This clock is used to transfer Header information and payload data
through the RXD serial bus to the network processor. This clock reflects the bit rate in use. RXCLK is
held to a logic "0" state during the CRC16 reception. RXCLK becomes active after the SFD has been
detected. Data should be sampled on the rising edge. This polarity is programmable and can be
inverted.
HFA3861B
4
External Interfaces
There are three primary digital interface ports for the
HFA3861B that are used for configuration and during
normal operation of the device as shown in Figure 1. These
ports are:
The
Control Port
, which is used to configure, write and/or
read the status of the internal HFA3861B registers.
The
TX Port
, which is used to accept the data that needs
to be transmitted from the network processor.
The
RX Port
, which is used to output the received
demodulated data to the network processor.
In addition to these primary digital interfaces the device
includes a byte wide parallel
Test Port
which can be
configured to output various internal signals and/or data. The
device can also be set into various power consumption
modes by external control. The HFA3861B contains three
Analog to Digital (A/D) converters and four Digital to Analog
converters. The analog interfaces to the HFA3861B include,
the In phase (I) and quadrature (Q) data component inputs/
outputs, and the RF and IF receive automatic gain control
and transmit output power control.
MD_RDY
54
O
MD_RDY is an output signal to the network processor, indicating header data and a data packet are
ready to be transferred to the processor. MD_RDY is an active high signal that signals the start of data
transfer over the RXD serial bus. MD_RDY goes active when the SFD (Note) is detected and returns
to its inactive state when RX_PE goes inactive or an error is detected in the header.
RX_PE
61
I
When active, the receiver is configured to be operational, otherwise the receiver is in standby mode.
This is an active high input signal. In standby, RX_PE inactive, all RX A/D converters are disabled.
SD
3
I/O
SD is a serial bidirectional data bus which is used to transfer address and data to/from the internal
registers. The bit ordering of an 8-bit word is MSB first. The first 8 bits during transfers indicate the
register address immediately followed by 8 more bits representing the data that needs to be written or
read at that register. In the 4 wire interface mode, this pin is three-stated unless the R/W pin is high.
SCLK
4
I
SCLK is the clock for the SD serial bus. The data on SD is clocked at the rising edge. SCLK is an input
clock and it is asynchronous to the internal master clock (MCLK). The maximum rate of this clock is
11MHz or one half the master clock frequency, whichever is lower.
SDI
64
I
Serial Data Input in 3 wire mode described in Tech Brief 383. This pin is not used in the 4 wire interface
described in this data sheet. It should not be left floating.
R/W
5
I
R/W is an input to the HFA3861B used to change the direction of the SD bus when reading or writing
data on the SD bus. R/W must be set up prior to the rising edge of SCLK. A high level indicates read
while a low level is a write.
CS
6
I
CS is a Chip select for the device to activate the serial control port. The CS doesn't impact any of the
other interface ports and signals, i.e., the TX or RX ports and interface signals. This is an active low
signal. When inactive SD, SCLK, and R/W become "don't care" signals.
TEST 7:0
51, 50, 49,
48, 47, 46,
45, 44
I/O
This is a data port that can be programmed to bring out internal signals or data for monitoring. These
bits are primarily reserved by the manufacturer for testing. A further description of the test port is given
in the appropriate section of this data sheet.
RESET
63
I
Master reset for device. When active TX and RX functions are disabled. If RESET is kept low the
HFA3861B goes into the power standby mode. RESET does not alter any of the configuration register
values nor does it preset any of the registers into default values. Device requires programming upon
power-up See the section on Control Register 12 bit 7 for important initialization information.
MCLK
42
I
Master Clock for device. The nominal frequency of this clock is 44MHz. This is used internally to
generate all other internal necessary clocks and is divided by 2 or 4 for the transceiver clocks.
TXI
+/-
23/24
O
TX Spread baseband I digital output data. Data is output at the chip rate. Balanced differential 23+/24-.
TXQ
+/-
29/30
O
TX Spread baseband Q digital output data. Data is output at the chip rate. Balanced differential
29+/30-.
CompCap
33
I
Compensation Capacitor.
CompCap2
26
I
Compensation Capacitor.
CompRes1
32
I
Compensation Resistor.
CompRes2
27
I
Compensation Resistor.
NOTE: See CR10[3].
Pin Descriptions
(Continued)
NAME
PIN TYPE
I/O
DESCRIPTION
HFA3861B
5
Control Port (4 Wire)
The serial control port is used to serially write and read
data to/from the device. This serial port can operate up to a
11MHz rate or 1/2 the maximum master clock rate of the
device, MCLK (whichever is lower). MCLK must be running
and RESET must be inactive during programming. This
port is used to program and to read all internal registers.
The first 8 bits always represent the address followed
immediately by the 8 data bits for that register. The LSB of
the address is a don't care, but reserved for future
expansion. The serial transfers are accomplished through
the serial data pin (SD). SD is a bidirectional serial data
bus. Chip Select (CS), and Read/Write (R/W) are also
required as handshake signals for this port. The clock used
in conjunction with the address and data on SD is SCLK.
This clock is provided by the external source and it is an
input to the HFA3861B. The timing relationships of these
signals are illustrated in Figures 2 and 3. R/W is high when
data is to be read, and low when it is to be written. CS is an
asynchronous reset to the state machine. CS must be
active (low) during the entire data transfer cycle. CS selects
the serial control port device only. The serial control port
operates asynchronously from the TX and RX ports and it
can accomplish data transfers independent of the activity at
the other digital or analog ports.
The HFA3861B has 96 internal registers that can be
configured through the control port. These registers are
listed in the Configuration and Control Internal Register
table. Table 9 lists the configuration register number, a brief
name describing the register, the HEX address to access
each of the registers and typical values. The type indicates
whether the corresponding register is Read only (R) or
Read/Write (R/W). Some registers are two bytes wide as
indicated on the table (high and low bytes).
TXD
TXCLK
TX_RDY
RXD
RXC
MD_RDY
CS
SD
SCLK
R/W
SDI
RXI
RXQ
AGC
V
REF
I
REF
TX_PE
RX_PE
RESET
TEST
TX_PORT
RX_PORT
CONTROL_PORT
ANALOG
INPUTS
A/D
REFERENCE
POWER
DOWN
SIGNALS
TEST
PORT
8
HFA3861B
FIGURE 1. EXTERNAL INTERFACES
ANT_SEL
AGC
TXI
TXQ
ANALOG
OUTPUTS
NOTES:
1. The HFA3861B always uses the rising edge of SCLK to sample address and data and to generate read data.
2. These figures show the controller using the falling edge of SCLK to generate address and data and to sample read data.
FIGURE 2. CONTROL PORT READ TIMING
FIGURE 3. CONTROL PORT WRITE TIMING
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
SCLK
SD
CS
R/W
LSB
DATA OUT
MSB
MSB
ADDRESS IN
FIRST ADDRESS BIT
FIRST DATABIT OUT
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
SCLK
SD
CS
R/W
LSB
DATA IN
MSB
MSB
ADDRESS IN
HFA3861B
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