U2731B-NFN Atmel, U2731B-NFN Datasheet - Page 12

• Manufacturer Part Number: U2731B-NFN
• Description: IC FRONT-END DAB 8.5V 44-SSOP
• Manufacturer: Atmel

Specifications of U2731B-NFN

• Package / Case: 44-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Features: -
• Frequency: -
• Rf Type: -

Simple Two-wire Bus
Data Transfer
12
U2731B
I50 and I100 define the charge pump current:
Table 4. Current of Charge Pump
Mi defines the operation mode:
Table 5. Mode Selection
Note:
Format:
START - ADR - ACK - <instruction set> - STOP
The <instruction set> consists of a sequence of A bytes, B bytes, C bytes and D bytes
each followed by ACK. Always a triplet of these bytes (A, B, C or D) has to be completed
before a new triplet is started. If no new triplet is started the transmission can be finished
before the current triplet is finished.
Examples:
START - ADR - ACK - DB1 - ACK - DB2 - ACK - DB3 - ACK - CB1 - ACK - CB2 - ACK -
CB3 - ACK - AB1 - ACK - AB2 - ACK - AB3 - ACK - BB1 - ACK - BB2 - ACK - BB3 - ACK
- STOP
START - ADR - ACK - CB1 - ACK - CB2 - ACK - STOP
However:
START - ADR - ACK - DB1 - ACK - CB1 -ACK - STOP is not allowed.
Description:
I50
LOW
HIGH
LOW
HIGH
START
STOP
ACK
ADR
Bi
HIGH
LOW
LOW
M3
X
X
X
SW = HIGH switches on the output current ( = A, B, C)
HIGH
HIGH
LOW
M2
X
X
X
Start condition
Stop condition
Acknowledge
Address byte
byte i ( = A, B, C, D; i = 1, 2, 3)
HIGH
HIGH
LOW
M1
X
X
X
HIGH
HIGH
LOW
LOW
I100
HIGH
LOW
LOW
M0
X
X
X
RF mixer B active, f
RF mixer A active, f
RF mixer B active, f
Charge-pump Current
(nominal)/µA
IF mixer switched off
f
LO,IFMIX
f
LO,IFMIX
200
100
150
50
Mode
= 2
= f
LO,RFMIX
LO,RFMIX
LO,RFMIX
ref
4671C–DAB–06/04
f
ref
= f
= f
= f
VCO
VCO
VCO
/2