Rainbow Electronics DS1087L - Manual (Page 11)

DS1087L
3.3V Spread-Spectrum EconOscillator
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Application Information
Power-Supply Decoupling
To achieve the best results when using the DS1087L,
decouple the power supply with 0.01µF and 0.1µF
high-quality, ceramic, surface-mount capacitors.
Surface-mount components minimize lead inductance,
which improves performance, and ceramic capacitors
tend to have adequate high-frequency response for
decoupling applications. These capacitors should be
placed as close to the V
CC
and GND pins as possible.
Stand-alone Mode
SCL and SDA cannot be left floating even in stand-
alone mode. If the DS1087L never needs to be pro-
grammed in-circuit, including during production
testing, SDA and SCL can be wired high.
SDA
SCL
t HD:STA
t LOW
t HIGH
t R t F
t BUF
t HD:DAT
t SU:DAT REPEATED
START
t SU:STA
t HD:STA
t SU:STO
t SP
STOP START
Figure 5. 2-Wire AC Characteristics
SLAVE
ACK
1 0 1 1 R/W A0* A1*
SLAVE
ACK
A2*
MSB LSB
DEVICE IDENTIFIER DEVICE
ADDRESS
READ/
WRITE
MSB LSB
COMMAND/REGISTER ADDRESS
SLAVE
ACK
MSB LSB
b7 b6 b5 b4 b3 b2 b1 b0
SLAVE
ACK
STOP
*THE ADDRESS DETERMINED BY A0, A1, AND A2 MUST
MATCH THE ADDRESS SET IN THE ADDR REGISTER.
DATA
TYPICAL 2-WIRE WRITE TRANSACTION
EXAMPLE 2-WIRE TRANSACTIONS (WHEN A0, A1, AND A2 ARE ZERO)
A) SINGLE BYTE WRITE
-WRITE PRESCALER
REGISTER TO 128
B) SINGLE BYTE READ
-READ PRESCALER
REGISTER
START
START
START
B0h
B0h
SLAVE
ACK
SLAVE
ACK
02h
02h
SLAVE
ACK
SLAVE
ACK
DATA
SLAVE
ACK
STOP 1 0 1 1 0 0 0 0
1 0 1 1 0 0 0 0
b7 b6 b5 b4 b3 b2 b1 b0
0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0
1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0
REPEATED
START
DATA
MASTER
NACK
STOP
SLAVE
ACK
1 0 1 1 0 0 0 1
B1h
Figure 6. 2-Wire Transactions