PCA9635_7

© NXP B.V. 2009. All rights reserved.

Product data sheet

Rev. 07 — 16 July 2009

11 of 35

NXP Semiconductors

PCA9635

[1]

See Section 7.7 “Using the PCA9635 with and without external drivers” for more details. Normal LEDs can be driven directly in either

mode. Some newer LEDs include integrated Zener diodes to limit voltage transients, reduce EMI and protect the LEDs, and these must

be driven only in the open-drain mode to prevent overheating the IC.

[2]

Change of the outputs at the STOP command allows synchronizing outputs of more than one PCA9635. Applicable to registers from

02h (PWM0) to 17h (LEDOUT) only.

[3]

See Section 7.4 “Active LOW output enable input” for more details.

7.3.3 PWM0 to PWM15, individual brightness control

A 97 kHz fixed frequency signal is used for each output. Duty cycle is controlled through

256 linear steps from 00h (0 % duty cycle = LED output off) to FFh

(99.6 % duty cycle = LED output at maximum brightness). Applicable to LED outputs

programmed with LDRx = 10 or 11 (LEDOUT0 to LEDOUT3 registers).

(1)

1 to 0

OUTNE[1:0][3]

R/W

00

When OE = 1 (output drivers not enabled), LEDn = 0.

01*

When OE = 1 (output drivers not enabled):

LEDn = 1 when OUTDRV = 1

LEDn = high-impedance when OUTDRV = 0 (same as OUTNE[1:0] = 10)

10

When OE = 1 (output drivers not enabled), LEDn = high-impedance.

11

reserved

Table 6.

Legend: * default value.

Bit

Symbol

Access

Value

Description

Table 7.

PWM0 to PWM15 - PWM registers 0 to 15 (address 02h to 11h) bit description

Legend: * default value.

Address

Register

Bit

Symbol

Access

Value

Description

02h

PWM0

7:0

IDC0[7:0]

R/W

0000 0000* PWM0 Individual Duty Cycle

03h

PWM1

7:0

IDC1[7:0]

R/W

0000 0000* PWM1 Individual Duty Cycle

04h

PWM2

7:0

IDC2[7:0]

R/W

0000 0000* PWM2 Individual Duty Cycle

05h

PWM3

7:0

IDC3[7:0]

R/W

0000 0000* PWM3 Individual Duty Cycle

06h

PWM4

7:0

IDC4[7:0]

R/W

0000 0000* PWM4 Individual Duty Cycle

07h

PWM5

7:0

IDC5[7:0]

R/W

0000 0000* PWM5 Individual Duty Cycle

08h

PWM6

7:0

IDC6[7:0]

R/W

0000 0000* PWM6 Individual Duty Cycle

09h

PWM7

7:0

IDC7[7:0]

R/W

0000 0000* PWM7 Individual Duty Cycle

0Ah

PWM8

7:0

IDC8[7:0]

R/W

0000 0000* PWM8 Individual Duty Cycle

0Bh

PWM9

7:0

IDC9[7:0]

R/W

0000 0000* PWM9 Individual Duty Cycle

0Ch

PWM10

7:0

IDC10[7:0]

R/W

0000 0000* PWM10 Individual Duty Cycle

0Dh

PWM11

7:0

IDC11[7:0]

R/W

0000 0000* PWM11 Individual Duty Cycle

0Eh

PWM12

7:0

IDC12[7:0]

R/W

0000 0000* PWM12 Individual Duty Cycle

0Fh

PWM13

7:0

IDC13[7:0]

R/W

0000 0000* PWM13 Individual Duty Cycle

10h

PWM14

7:0

IDC14[7:0]

R/W

0000 0000* PWM14 Individual Duty Cycle

11h

PWM15

7:0

IDC15[7:0]

R/W

0000 0000* PWM15 Individual Duty Cycle

duty cycle

IDCx 7:0

[]

256

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