STW81103 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'STW81103' PDF : 53 Pages View PDF
STW81103
I2C bus interface
B_COUNTER
MSB
LSB
b7
b6
b5
b4
b3
b2
b1
b0
B10
B9
B8
B7
B6
B5
B4
B3
B[10:3]. B counter value (bit B11 in the previous register, bits B[2:0] in the next register)
A_COUNTER
MSB
LSB
b7
b6
b5
b4
b3
b2
b1
b0
B2
B1
B0
A4
A3
A2
A1
A0
Bits B[2:0] for B_COUNTER, A_COUNTER values.
REF_DIVIDER
MSB
LSB
b7
b6
b5
b4
b3
b2
b1
b0
R9
R8
R7
R6
R5
R4
R3
R2
Reference clock divider ratio R[9:1] (bits R1, R0 in the next register).
CONTROL
MSB
LSB
b7
b6
b5
b4
b3
b2
b1
b0
R1
R0
PLL_A1 PLL_A0 CPSEL2 CPSEL1 CPSEL0 PSC_SEL
The CONTROL register is used to set the charge pump current, the VCO output voltage
amplitude and the prescaler modulus:
PLL_A[1:0]: VCO amplitude
CPSEL[2:0]: charge pump output current
PSC_SEL: prescaler modulus select ('0' for P=16, '1' for P=19)
The LO output frequency is programmed by setting the proper values for A, B and R
according to the following formula:
FOUT
=
DR ×
(B ×
P +A) ×
-F---R-----E----F------–----C-----L---K---
R
where DR equals
{
1
0.5
for direct output
for output divided by 2
0.25 for output divided by 4
and P is the selected prescaler modulus.
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