Sony Ericsson GR47/GR48 - Manual (Page 48)

5. SYSTEM CONNECTOR INTERFACE
48
LZT 123 7589 R1A
1RWH
If the voltage of the signal to be measured may be altered by the internal
circuitry of this shared signal, then the application should use ADC1,
ADC2 or ADC3 instead.
Figure 5.12 Input circuit for combined digital I/O and ADC pins
5.17 External I 2 C Serial Control Bus
The I
2
C bus is controlled by embedded application script commands.
The external I
2
C bus consists of two signals, SDA and SCL. This bus is
isolated from the radio device’s internal I
2
C bus to ensure proper operation
of the radio device, in the event of the external I
2
C bus being damaged.
The electrical characteristics are shown below.
2.75V
ADC
100kΩ
10kΩ
A
2.75V
Analog IC
10#/ADC#
1MΩ
1nF
Pin Signal Dir Description
29 SDA I/O
I 2 C serial data
30 SCL O
I 2 C serial clock
Parameter Min. Typ. Max. Units
Tr
a
ns
m
it
oper
ation
Frequency I 2 C CLK
81.25 400 kHz
High or low I 2 C CLK 1.2 µs
Delay time after falling edge of I 2 C
CLK
308 308-
1230
ns
Hold time after falling edge of I 2 C
CLK
0 ns