MAX11646 Datasheet, PDF (13/20 Pages) Maxim Integrated Products – 2.7V to 3.6V and 4.5V to 5.5V, Low-Power, 1-/2-Channel, 2-Wire Serial, 10-Bit ADCs

2.7V to 3.6V and 4.5V to 5.5V, Low-Power,
1-/2-Channel, 2-Wire Serial, 10-Bit ADCs
Configuration/Setup Bytes (Write Cycle)
A write cycle begins with the bus master issuing a
START condition followed by 7 address bits (Figure 7)
and a write bit (R/W = 0). If the address byte is success-
fully received, the MAX11646/MAX11647 (slave) issue
an acknowledge. The master then writes to the slave.
The slave recognizes the received byte as the setup
byte (Table 1) if the most significant bit (MSB) is 1. If the
MSB is 0, the slave recognizes that byte as the configu-
ration byte (Table 2). The master can write either 1 or 2
bytes to the slave in any order (setup byte then configu-
ration byte, configuration byte then setup byte, setup
byte or configuration byte only; see Figure 9). If the
slave receives a byte successfully, it issues an acknowl-
edge. The master ends the write cycle by issuing a
STOP condition or a repeated START condition. When
operating in HS mode, a STOP condition returns the bus
into F/S mode (see the HS Mode section).
MASTER TO SLAVE
SLAVE TO MASTER
A. 1-BYTE WRITE CYCLE
1
7
11
8
11
S
SLAVE ADDRESS
WA
SETUP OR
CONFIGURATION BYTE
A
P or Sr
NUMBER OF BITS
MSB DETERMINES WHETHER
SETUP OR CONFIGURATION BYTE
B. 2-BYTE WRITE CYCLE
1
7
11
8
1
8
11
S
SLAVE ADDRESS
WA
SETUP OR
CONFIGURATION BYTE
A
SETUP OR
CONFIGURATION BYTE
A P or Sr
NUMBER OF BITS
Figure 9. Write Cycle
MSB DETERMINES WHETHER
SETUP OR CONFIGURATION BYTE
Table 1. Setup Byte Format
BIT 7
(MSB)
REG
BIT 6
SEL2
BIT 5
SEL1
BIT 4
SEL0
BIT 3
CLK
BIT 2
BIP/UNI
BIT 1
RST
BIT 0
(LSB)
X
BIT
NAME
DESCRIPTION
7
REG
Register bit. 1 = setup byte, 0 = configuration byte (see Table 2).
6
SEL2
5
SEL1
Three bits select the reference voltage (Table 6). Default to 000 at power-up.
4
SEL0
3
CLK
1 = external clock, 0 = internal clock. Defaulted to 0 at power-up.
2
BIP/UNI
1 = bipolar, 0 = unipolar. Defaulted to 0 at power-up (see the Unipolar/Bipolar section).
1
RST
1 = no action, 0 = resets the configuration register to default. Setup register remains unchanged.
0
X
Don’t-care bit. This bit can be set to 1 or 0.
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