S1A0903X01-Q0R0 Samsung Electronics, S1A0903X01-Q0R0 Datasheet - Page 32

• Manufacturer Part Number: S1A0903X01-Q0R0
• Description: AM/FM 1 Chip Tuner with PLL
• Manufacturer: Samsung Electronics

S1A0903X01
MPX VCO FREE-RUNNING-FREQUENCY SELF-ADJUSTING CONTROLLER
32
Whenever band is switched to the FM mode, FM MPX VCO free-running frequency will be adjusted between
302.5kHz and 309.5kHz using control code PD[6:0]
A region : wait time for MPX VCO to oscillate due to band switching.
B region : measure MPX VCO free-running frequency and check whether free-running frequency is between
302.5kHz
the control code and end the adjusting.
C region : reduce control code PD[6:0] into 1 step, make free-running frequency fast. If PD[6:0] is
1111111(bin), VCO frequency will be minimum frequency and If PD[6:0] is 0000000(bin), VCO frequency will
be maximum frequency.
In adjusting MPX VCO free-running, MUTE will be set to one.
The result of MPX VCO free-running adjust is out through TEST1 pin, when TEST[1:0] is zero.
TEST1 pin = 1 : operating VCO free-running adjustment
TEST1 pin = 0 : success adjusting VCO free-running between 302.5kHz
TEST1 pin = 1.172kHz/2 : 1.172kHz/2 frequency is out when first adjustment cycle
(maximum adjustment time : 164.7ms / 1 cycle) is failed. Try to adjust VCO free-running on and on,
TEST1 pin is set to be zero when VCO free-running frequency is between 302.5kHz
ADJUST
PD[6:0]
FMSW
MODE
TC
309.5kHz or not. If MPX VCO free-running frequency is between 302.5kHz
Figure 17. MPX VCO Free-Running Adjustment Timing Diagram
55.47ms
1111111
A
0.853ms
B
0.853ms
1111110
C
1111101
AM/FM 1CHIP TUNER WITH PLL
309.5kHz
XXXXXXX
309.5kHz, hold
309.5kHz