TCA6507_10 Datasheet, PDF (8/32 Pages) Texas Instruments – LOW-VOLTAGE 7-BIT I2C AND SMBus LED DRIVER WITH INTENSITY CONTROL AND SHUTDOWN

TCA6507
LOW-VOLTAGE 7-BIT I²C AND SMBus LED DRIVER
WITH INTENSITY CONTROL AND SHUTDOWN
SCPS164B – MAY 2007 – REVISED NOVEMBER 2007
Register Descriptions
www.ti.com
The Select0 register (register 0), Select1 (register 1), and Select2 register (register 2) configure the state of each
of the outputs (see Table 4) .
SELECT2
0
0
0
0
1
1
1
1
SELECT1
0
0
1
1
0
0
1
1
Table 4. Select2, Select1, and Select0 Register States
SELECT0
0
1
0
1
0
1
0
1
STATE
LED off (high impedance)
LED off (high impedance)
LED on steadily with maximum intensity value of PWM0 (ALD value or BRIGHT_F0 value)
LED on steadily with maximum intensity value of PWM1 (ALD value or BRIGHT_F1 value)
LED fully on (output low). Can be used as general-purpose output
LED on at brightness set by One Shot / Master Intensity register
LED blinking with intensity characteristics of BANK0 (PWM0)
LED blinking with intensity characteristics of BANK1 (PWM1)
BIT
DEFAULT
(1) X = Don't care
Table 5. Register 0 (Select0 Register)
S0-7
X ⁽¹⁾
S0-6
0
S0-5
0
S0-4
0
S0-3
0
S0-2
0
S0-1
0
S0-0
0
BIT
DEFAULT
(1) X = Don't care
Table 6. Register 1 (Select1 Register)
S1-7
X ⁽¹⁾
S1-6
0
S1-5
0
S1-4
0
S1-3
0
S1-2
0
S1-1
0
S1-0
0
Table 7. Register 2 (Select2 Register)
BIT
DEFAULT
S1-7
X ⁽¹⁾
S1-6
0
S1-5
0
S1-4
0
S1-3
0
S1-2
0
S1-1
0
S1-0
0
(1) X = Don't care
To use a P port as a general-purpose output, Select1 and Select0 registers must be set low (or 0), then the
inverse of the data written to the Select2 bit appears on the open-drain output.
The intensity of each bank of LEDs can be customized by programming six registers: Fade-On Time, Fully-On
Time, Fade-Off Time, First Fully-Off Time, Second Fully-Off Time, and Maximum Intensity registers. Each bank is
designed to produce two identical intensity pulses per blink cycle. Both pulses have the same fade-on, fully-on
and fade-off times, but independent fully-off times to achieve a double-blink effect when desired.
The Fade-On Time register (register 3) defines the time from the fully-off state to the fully-on state for the LED
per region A in Figure 7. The first four bits (C7–C4) in this register set the fade-on time for BANK1, and the next
four bits (C3–C0) set the fade-on time for BANK0. The data for each bank is a binary number between 0 and 15.
For BANK1, the MSB is bit C7, while the least significant bit (LSB) is bit C4. For BANK0, the MSB is bit C3 while
the LSB is bit C0. See Table 13 for more information.
BANK
BIT
DEFAULT
Table 8. Register 3 (Fade-On Time Register)
BANK1
BANK0
C7
C6
C5
C4
C3
C2
C1
C0
0
1
0
0
0
1
0
0
8
Submit Documentation Feedback
Product Folder Link(s): TCA6507
Copyright © 2007, Texas Instruments Incorporated