RFB433B Micrel Inc, RFB433B Datasheet - Page 5

• Manufacturer Part Number: RFB433B
• Manufacturer: Micrel Inc

Specifications of RFB433B

• Operating Frequency (max): 434000kHz
• Operating Temperature (min): -20C
• Operating Temperature Classification: Commercial
• Modulation Type: FSK
• Operating Supply Voltage (typ): 3V
• Lead Free Status / Rohs Status: Not Compliant

The 80bit control word is first read into a shift-register, and is
then loaded into a parallel register by a transition of the REG
signal (positive or negative) when the CLK signal is high. The
circuit then goes directly into the specified mode (receive,
transmit, etc.).
Figure 1: Timing of CLK, REG and the internal Load_int
and PA_C signals for the first time after power on.
1: The second last bit is clocked into the first shift register (‘1’).
2: The last bit is clocked into the first shift register (‘1’).
3: A transition on the REG signal generates an internal load
pulse that loads the control word into the parallel register. The
circuit enters the new mode (in this case Tx-mode). The circuit
stabilizes in the new mode.
4: The PIN should be brought low when the clock signal goes
low. When the clock signal is low the power amplifier (PA) is
turned on slowly in order to minimize spurious components on
the RF output signal. To be sure the PLL is in lock before the
PA is turned on, the PA should be turned on after LD.
The negative transition on the clock signal should come a
minimum time of one period of the comparison frequency after
the internal load pulse is generated.
5: The power amplifier is fully turned on.
6: A new control word is entered into the first register. A
transition on the REG signal when CLK is high will now turn
the power amplifier off.
7: When the power amplifier is turned off, an internal load
pulse is generated. The PIN should be brought high when the
PA is off. New control word is loaded into the parallel register
and the circuit enters a new mode (in this case power down
mode). CLK must go low after the internal load pulse is
generated.
As long as transitions on REG are avoided when CLK is high,
a new control word can be clocked into the first register any
time without affecting the operation of the transceiver.
The N, M and A values can be calculated from the formula:
where f
Hovfaret 17B, N-0275 Oslo, Norway. Tel: [phone] Fax: [phone] E-mail:
f
XCO
M
XCO
32
is the crystal oscillator frequency and is 16MHz.
f
N
RF
A
Example1: f
Binary form: (MSB to the left):
Tx: 010110 010110 000001100000
000001100000 0001110010 0001110010
011110000000001100000011
Rx: 010110 010110 000001100000
000001100000 0001110010 0001110010
011110000000001100000001
Example2: f
Binary form: (MSB to the left):
Tx: 011010 011010 000001100101
000001100101 0001111000 0001111000
011110000000001100000011
Rx: 011010 011010 000001100101
000001100101 0001111000 0001111000
011110000000001100000001
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
[e-mail]
A1
22
22
p57
0
0
Ref6
0
0
Ref0
0
0
p75
0
0
A1
26
26
p57
0
0
Ref6
0
0
Ref0
0
0
p75
0
0
RF
RF
= 434.245MHz fxco= 16MHz
= 433.4MHz fxco:16MHz
A0
22
22
Pa2
1
1
Ref5
0
0
Cpmp1
0
0
p76
0
0
A0
26
26
Pa2
1
1
Ref5
0
0
Cpmp1
0
0
p76
0
0
Orgnr. NO 929 510 909 www.bluechip.no
N1
96
96
Pa1
1
1
Ref4
0
0
Cpmp0
1
1
p77
0
0
N1
101
101
Pa1
1
1
Ref4
0
0
Cpmp0
1
1
p77
0
0
N0
96
96
Pa0
1
1
Ref3
0
0
p72
1
1
p78
0
0
N0
101
101
Pa0
1
1
Ref3
0
0
p72
1
1
p78
0
0
M1
114
114
Gc
1
1
Ref2
0
0
p73
0
0
M1
120
120
Gc
1
1
Ref2
0
0
p73
0
0
RT
1
0
RT
1
0
M0
114
114
ByLNA
0
0
Ref1
0
0
p74
0
0
M0
120
120
ByLNA
0
0
Ref1
0
0
p74
0
0
Pu
1
1
Pu
1
1