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零件编号 | U4285BM-AFSG3 | ||
描述 | AM / FM - PLL | ||
制造商 | TEMIC Semiconductors | ||
LOGO | |||
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AM / FM - PLL
U4285BM
Description
The U4285BM is an integrated circuit in BICMOS
technology for frequency synthesizers. It performs all the
functions of a PLL radio tuning system and is controlled
by an I2C bus. The device is designed for all frequency
synthesizer applications in radio receivers, as well as
RDS ( Radio Data System ) applications.
Features
D Reference oscillator up to 15 MHz
D Two programmable 16 bit dividers
adjustable from 2 to 65535
D Fine tuning steps:
yAM 1 kHz
yFM 2 kHz
D 4 programmable switching outputs
(open drain up to 15 V)
D Few external component required due to
integrated loop-push-pull stage for AM/FM
D High signal/ noise ratio
Ordering Information
Extended Type Number
U4285BM-AFS
U4285BM-AFSG3
Package
SSO20 plastic
SSO20 plastic
Remarks
Taping according to IEC-286-3
Block Diagram
OSCIN 18
OSCOUT
19
SCL 2
SDA 3
AS 4
Oscillator
I2C bus
interface
FMOSC 9
AMOSC 11
AM/FM
switch
10
GND2
R-divider
SWO1 SWO2 SWO3 SWO4
5678
Switching outputs
Phase
detector
Current
sources
N-divider
1
VDD
Figure 1.
20
GND1
14 PDAM
15 PDAMO
16 VA
17 C
12 PDFMO
13 PDFM
95 10120
TELEFUNKEN Semiconductors
Rev. A3, 14-May-97
1 (10)
U4285BM
Recommendations for Applications
D C3 = 100 nF should be very close to Pin 1 (VDD) and
Pin 20 (GND 1)
D GND 2 (Pin 10 – analogue ground) and GND 1
(Pin 20 – digital ground) must be connected according
to figure 8
D 4 MHz crystal must be very close to Pin 18 and Pin 19
D Components of the charge pump (C1/R1 for AM and
C2/R2 for FM) should be very close to Pin 14 with
respect to Pin 13.
PCB-Layout
GND
C1 C2
20 19 18 17 16 15 14 13 12 11
C4
VDD
C3
1 2 3 4 5 6 7 8 9 10
Figure 8.
95 10124
8 (10)
TELEFUNKEN Semiconductors
Rev. A3, 14-May-97
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页数 | 10 页 | ||
下载 | [ U4285BM-AFSG3.PDF 数据手册 ] |
零件编号 | 描述 | 制造商 |
U4285BM-AFSG3 | AM / FM - PLL | TEMIC Semiconductors |
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