U4285BM-AFS TEMIC Semiconductors, U4285BM-AFS Datasheet - Page 2

• Manufacturer Part Number: U4285BM-AFS
• Description: AM / FM - PLL
• Manufacturer: TEMIC Semiconductors

Pin Description
Functional Description
The U4285BM is controlled via the 2-wire I
programming there are one module address byte, two sub-
address bytes and five data bytes.
The module address contains a programmable address bit
A 1 which with address select input AS (Pin 4) makes it
possible to operate two U4285BM in one system. If bit
A 1 is identical with the status of the address select input
AS, the chip is selected .
The subaddress determines which one of the data bytes is
transmitted first. If subaddress of R-divider is trans-
mitted, the sequence of the next data bytes is DB 0
(Status), DB 1 and DB 2.
If subaddress of N-divider is transmitted, the sequence of
the next data bytes is DB 3 and DB 4. The bit organisation
U4285BM
2 (10)
SCL
SDA
AS
SWO 1
SWO 2
SWO3
SWO4
FMOSC
GND 2
V
DD
10
6
2
3
7
9
1
4
5
8
U4285BM
20
19
18
17
16
15
14
12
13
11
95 10121
GND1
OSCOUT
OSCIN
C
VA
PDAMO
PDAM
PDFM
PDFMO
AMOSC
2
C bus. For
of the module address, subaddress and 5 data bytes are
shown in figure 2.
Each transmission on the I
“START”- condition and has to be ended by the “STOP”-
condition (see figure 3).
The integrated circuit U4285BM has two separate inputs
for AM and FM oscillator. Pre-amplified AM and FM
signals are fed to the 16 bit N-divider via AM/FM switch.
AM/FM switch is controlled by software. Tuning steps
can be selected by 16 bit R-divider. Further there is a
digital memory phase detector. There are two separate
current sources for AM and FM amplifier (charge pump)
as given in electrical characterisitics. It allows indepen-
dent adjustment of gain, whereby providing high current
for high speed tuning and low current for stable tuning.
Pin
10
11
12
13
14
15
16
17
18
19
20
1
2
3
4
5
6
7
8
9
OSCOUT Oscillator output
PDAMO
AMOSC
FMOSC
PDFMO
Symbol
SWO 1
SWO 2
OSCIN
GND 2
PDAM
SWO3
SWO4
PDFM
GND1
SDA
V
SCL
VA
AS
C
DD
Supply voltage
I
I
Address selection
Switching output 1
Switching output 2
Switching output 3
Switching output 4
FM oscillator input
Ground 2 (analog)
AM oscillator input
FM analogue output
FM current output
AM current output
AM analogue output
Analogue supply voltage
Capacitor
Oscillator input
Ground 1 (digital)
TELEFUNKEN Semiconductors
2
2
C bus clock
C bus data
2
C bus begins with the
Function
Rev. A3, 14-May-97