TSA5515T View Datasheet(PDF) - Philips Electronics
Part Name
Description
View to exact match
TSA5515T Datasheet PDF : 15 Pages
| |||
Philips Semiconductors
1.3 GHz bi-directional I2C-bus controlled synthesizer
Product specification
TSA5515T
FUNCTIONAL DESCRIPTION
The TSA5515T is controlled via the two-wire I2C-bus. For
programming, there is one module address (7 bits) and the
R/W bit for selecting READ or WRITE mode.
WRITE mode:
R/W = 0 (see Table 1)
After the address transmission (first byte), data bytes can
be sent to the device. Four data bytes are needed to fully
program the TSA5515T. The bus transceiver has an
auto-increment facility, which permits the programming of
the TSA5515T within one single transmission
(address + 4 data bytes).
The TSA5515T can also be partly programmed on the
condition that the first data byte following the address is
byte 2 or byte 4. The meaning of the bits in the data bytes
is given in Table 1. The first bit of the first data byte
transmitted indicates whether frequency data (first bit = 0)
or charge pump and port information (first bit = 1) will
follow. Until an I2C-bus STOP condition is sent by the
controller, additional data bytes can be entered without the
need to re-address the device. This allows a smooth
frequency sweep for fine tuning. At power-on, the ports are
set to the high impedance state.
The 7.8125 kHz reference frequency is obtained by
dividing the output of the 4 MHz crystal oscillator by 512.
Because the input of the UHF/VHF signal is first divided by
8, the step size is 62.5 kHz. A 3.2 MHz crystal can offer a
step size of 50 kHz.
Table 1 Write data format
MSB
LSB
Address
1
1
0
0
0 MA1 MA0
0
Programmable
divider
0
N14 N13 N12 N11 N10 N9
N8
Programmable
divider
N7
N6 N5 N4 N3 N2 N1
N0
Charge-pump
and test bits
1
CP
T1
T0
X
X
X
OS
Output ports control P7
X
X
X
X
P2 P1
X
bits
A byte 1
A byte 2
A byte 3
A byte 4
A byte 5
MA1, MA0 programmable address bits (see Table 3)
A
N14 to N0
N = N14 × 214+N13 × 213+...+N1 × 21+N0
CP
CP = 0
CP = 1
P7, P2, P1 = 1
P7, P2, P1 = 0
T1, T0, OS = 0 0 0
T1 = 1, P2 = fref, P7 = fDIV
T0 = 1
OS = 1
acknowledge bit
programmable divider bits
charge-pump current
50 µA
220 µA
open-collector outputs are active
outputs are in high impedance state
normal operation
3-state charge-pump
operational amplifier output is switched off (varicap drive disable)
Note
1. X = don’t care
November 1991
6
|
|
Share Link: 