MAX1497 Datasheet, PDF (18/33 Pages) Maxim Integrated Products – 3.5- and 4.5-Digit, Single-Chip ADCs with LED Drivers and μC Interface

3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
Table 5. Register Address Table
REGISTER
N0.
1
2
3
4
5
6
7
8
9
10
11
12
—
ADDRESS
RS [4:0]
00000
00001
00010
00011
00100
00101
00110
00111
01000
01001
01010
10100
All other addresses
NAME
Status register
Control register
Overrange register
Underrange register
LED segment-display register 1
LED segment-display register 2
LED segment-display register 3
ADC custom offset register
ADC result register 1 (16 MSBs)
LED data register
Peak register
ADC result register 2 (4 LSBs)
Reserved
WIDTH
8
16
16
16
16
16
8
16
16
16
16
8
—
ACCESS
Read only
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Read only
R/W
Read only
Read only
—
DV_DD
DOUT
C_LOAD ^DOUT
6kΩ
50pF
6kΩ
C_LOAD
50pF
GND
A) V_OH TO HIGH-Z
GND
B) V_OL TO HIGH-Z
Figure 13. Load Circuits for Disable Time
bits have been transferred (8 or 16). Once this has
occurred, the MAX1497/MAX1499 wait for the next
command byte. CS must not go high between data
transfers. If CS is toggled before the end of a write or
read operation, the device mode may be unknown.
Clock in 32 zeros to clear the device state and reset the
interface so it is ready to receive a new command byte.
On-Chip Registers
The MAX1497/MAX1499 contain 12 on-chip registers.
These registers configure the various functions of the
device and allow independent reading of the ADC
results and writing to the LED display. Table 5 lists the
address and size of each register.
The first of these registers is the status register. The 8-
bit status register contains the status flags for the ADC.
DV_DD
DOUT
C_LOAD ^DOUT
6kΩ
50pF
6kΩ
C_LOAD
50pF
GND
B) HIGH-Z TO V_OH AND V_OL TO V_OH
GND
B) HIGH-Z TO V_OL AND V_OH TO V_OL
Figure 14. Load Circuits for Enable Time
The second register is the 16-bit control register. This
register sets the LED display controls, range modes,
power-down modes, offset calibration, and the reset
register function (CLR). The third register is the 16-bit
overrange register, which sets the overrange limit of the
analog input. The fourth register is the 16-bit under-
range register, which sets the underrange limit of the
analog input. Registers 5 through 7 contain the display
data for the individual segments of the LED. The eighth
register contains the custom offset value. The ninth reg-
ister contains the 16 MSBs of the ADC conversion
result. The 10th register contains the LED data. The
11th register contains the peak analog input value. The
last register contains the lower four LSBs of the 20-bit
ADC conversion result.
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