pca9634 NXP Semiconductors, pca9634 Datasheet - Page 17

• Manufacturer Part Number: pca9634
• Description: Pca9634 8-bit Fm I2c-bus Led Driver
• Manufacturer: NXP Semiconductors

NXP Semiconductors
Table 15.
[1]
[2]
[3]
[4]
PCA9634_4
Product data sheet
INVRT OUTDRV Direct connection to LEDn
0
0
1
1
When OE = 1, LED output state is controlled only by OUTNE[1:0] bits (MODE2 register).
Correct configuration when LEDs directly connected to the LEDn outputs (connection to V
Optimum configuration when external N-type (NPN, NMOS) driver used.
Optimum configuration when external P-type (PNP, PMOS) driver used.
0
1
0
1
Use of INVRT and OUTDRV based on connection to the LEDn outputs when OE = 0
7.7 Using the PCA9634 with and without external drivers
Firmware
formulas and LED
output state values
apply
formulas and LED
output state values
apply
formulas and LED
output state values
inverted
formulas and LED
output state values
inverted
The PCA9634 LED output drivers are 5.5 V only tolerant and can sink up to 25 mA at 5 V.
If the device needs to drive LEDs to a higher voltage and/or higher current, use of an
external driver is required.
[2]
[2]
•
•
INVRT bit (MODE2 register) can be used to keep the LED PWM control firmware the
same (PWMx and GRPPWM values directly calculated from their respective formulas
and the LED output state determined by LEDOUT register value) independently of the
type of external driver. This bit allows LED output polarity inversion/non-inversion only
when OE = 0.
OUTDRV bit (MODE2 register) allows minimizing the amount of external components
required to control the external driver (N-type or P-type device).
External
pull-up
resistor
LED current
limiting R
LED current
limiting R
LED current
limiting R
LED current
limiting R
Rev. 04 — 5 January 2007
[2]
[2]
External N-type driver
Firmware
formulas and LED
output state
values inverted
formulas and LED
output state
values inverted
formulas and LED
output state
values apply
formulas and LED
output state
values apply
[3]
External
pull-up
resistor
required
not required formulas and LED
required
not
required
DD
[3]
through current limiting resistor).
8-bit Fm+ I
External P-type driver
Firmware
formulas and LED
output state values
apply
output state values
apply
formulas and LED
output state values
inverted
formulas and LED
output state values
inverted
[4]
[1]
PCA9634
2
© NXP B.V. 2007. All rights reserved.
C-bus LED driver
External
pull-up
resistor
required
not
required
required
not required
17 of 37
[4]