PCA9685BS NXP [NXP Semiconductors], PCA9685BS Datasheet - Page 28

• Manufacturer Part Number: PCA9685BS
• Description: 16-channel, 12-bit PWM Fm+ I2C-bus LED controller
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
Table 11.
[1]
[2]
[3]
[4]
PCA9685_2
Product data sheet
INVRT OUTDRV Direct connection to LEDn
0
0
1
1
Fig 13. External N-type driver
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
LED0
INVRT = 0
OUTDRV = 1
Use of INVRT and OUTDRV based on connection to the LEDn outputs when OE = 0
7.7 Using the PCA9685 with and without external drivers
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
+5 V
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The PCA9685 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 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
Fig 14. External P-type driver
LED0
Rev. 02 — 16 July 2009
INVRT = 1
OUTDRV = 1
[2]
[2]
External N-type driver
Firmware
formulas and LED
output state
values inverted
formulas and LED
output state
values apply
formulas and LED
output state
values apply
formulas and LED
output state
values inverted
16-channel, 12-bit PWM Fm+ I
+5 V
002aad170
[3]
External
pull-up
resistor
required
not
required
required
not required formulas and LED
DD
Fig 15. Direct LED connection
[3]
through current limiting resistor).
External P-type driver
Firmware
formulas and LED
output state values
apply
formulas and LED
output state values
inverted
formulas and LED
output state values
inverted
output state values
apply
LED0
INVRT = 1
OUTDRV = 0
[4]
2
C-bus LED controller
[1]
PCA9685
© NXP B.V. 2009. All rights reserved.
002aad171
External
pull-up
resistor
required
not required
required
not
required
+V
DD
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[4]