LED controllers: Voltage-switch drivers, constant-current drivers, and Flash LED drivers

LED controllers
Voltage-switch drivers, constant-current
drivers, and Flash LED drivers
LEDs are used in a wide range of applications, from low-end status indicators to high-end video displays. System designers often
need the ability to control these LEDs, but can’t afford to tie up the system processor to do so. NXP’s LED controllers solve this
problem, performing a variety of control tasks while offloading the system processor. Having sent instructions to the LED controller,
the processor is free to engage in other tasks or go into a low-power state.
NXP’s LED controllers offer a variety of features needed in LED-driving applications. Some of these features include:
} Blinking and dimming capability
} Pulse-width modulation (PWM) for LED control
} Color mixing capabilities
} Fast-mode Plus (Fm+) bi-directional communication channel with data transfer rate of up to 1 Mbps over the I2C-bus
} Ultra Fast-mode (UFm) uni-directional communication channel with data transfer rate of up to 5 Mbps over the I2C-bus
} SPI-compatible 3-wire serial uni-directional interface with data transfer rate of up to 25 Mbps over Serial Peripheral Interface (SPI)
} Different output drive types (push-pull, open-drain voltage switch or constant-current driver)
} Independent control of LEDs
} LED Open or Short status and fault reading
} Gradation control with programmable “breathing” effect
} Short-circuit protection
} Over-temperature protection
The devices are classified in three groups: voltage-switch drivers, constant-current drivers, and Flash LED drivers.
These groups are discussed below.
Voltage-Switch Drivers
Voltage-switch output driver devices control the LED
connected to the output pin by switching the connection
to ground or supply on or off. A series resistor connected
between the LED and the device limits the current that flows
through the LED into the device.
Voltage-switch devices have the advantage of dissipating the
heat outside the device, in the series resistor. Therefore the
device is insensitive to heat dissipation and is good for driving
multiple LEDs in series, with different forward-bias voltages
(Vf ), from the same supply.
(a) Example Voltage-Switch Output Structure
Constant-Current Drivers
A current-regulated LED driver results in the LED light
remaining constant with the supply-voltage fluctuations.
NXP constant-current LED drivers are used for low-current
luminary lighting applications requiring accurate lighting
control independent of supply voltage, temperature, and LED
forward-bias voltage.
Flash LED Drivers
NXP Flash LED Drivers are high-efficiency, maximum-output,
small footprint devices with touch capability and an indicator
LED output feature. These devices are highly integrated with
hardware and I2C interface modes.
(b) Example Constant-Current Output Structure
The LED controllers are supported by application boards and daughter cards, an established manufacturing infrastructure that
supports high volumes, and several technical documents. NXP helps system designers make lighting affordable, in everything
from indoor consumer electronics and appliances to outdoor decorative lighting.
Thermal Shutdown
Interface
2
256
N/A
Y
N
N
N
N
N
I2C, Fm
25 mA
5V
Open Drain
(Sink)
Y
2
256
N/A
N
N
N
N
N
N
I C, Fm
25 mA
5V
Open Drain
(Sink)
Y
2
256
N/A
N
N
N
N
N
N
I2C, Fm
25 mA
5V
Open Drain
(Sink)
Y
2
256
N/A
N
N
N
N
N
N
I C, Fm
25 mA
5V
Open Drain
(Sink)
Y
2
256
N/A
Y
N
N
N
N
N
I2C, Fm
Status
LED Error Detection
Y
Group PWM Frequency
Programmable Output Delay
Open Drain
(Sink)
2
Y
0.172 Hz 44 Hz
N/A
In Production
1
N
0.172 Hz 44 Hz
N/A
In Production
8
Y
0.172 Hz 44 Hz
N/A
In Production
8
Y
0.172 Hz 44 Hz
N/A
In Production
2
Y
0.591 Hz 152 Hz
N/A
In Production
N/A
In Production
N/A
In Production
Individual PWM Frequency
Output Enable / PWM Control
5V
Hardware Reset
Group Brightness Control
25 mA
Number of Device Addresses
Individual Brightness Control
Voltage
switch
Group PWM Resolution (Steps)
1.9 µA
Individual PWM Resolution (Steps)
1.9 µA
Voltage
switch
Number of PWMs
Voltage
switch
LED Pin can be used as Input
1.9 µA
Output Type
2.3 V 5.5 V
Max LED Drive Voltage
Operating Voltage Range
2
Max LED Drive Current
Number of LED Outputs
Blinker
Type of LED Drive
Function
PCA9550
Standby Current [1]
Device
LED Controllers Selection Guide
PCA9553
Blinker
4
2.3 V 5.5 V
PCA9551
Blinker
8
2.3 V 5.5 V
2.1 µA
Voltage
switch
1.9 µA
Voltage
switch
25 mA
5V
Open Drain
(Sink)
Y
2
256
N/A
N
N
N
N
N
N
I C, Fm
1
N
0.591 Hz 152 Hz
25 mA
5V
Open Drain
(Sink)
Y
2
256
N/A
N
N
N
N
N
N
I2C, Fm
8
Y
0.591 Hz 152 Hz
Y
2
256
N/A
N
N
N
N
N
N
I C, Fm
8
Y
0.591 Hz 152 Hz
N/A
In Production
N
4+1
256
64
Y
Y
N
N
N
N
I2C, Fm+
1, 4
N
1.56 KHz
190 Hz
(6.25 KHz)
In Production
N
97 KHz
190 Hz
(97 KHz)
In Production
N
97 KHz
190 Hz
(97 KHz)
In Production
N
97 KHz
190 Hz
(97 KHz)
In Production
2
PCA9552
Blinker
16
2.3 V 5.5 V
PCA9530
Dimmer &
Blinker
2
2.3 V 5.5 V
PCA9533
Dimmer &
Blinker
4
2.3 V 5.5 V
1.9 µA
Voltage
switch
PCA9531
Dimmer &
Blinker
8
2.3 V 5.5 V
1.9 µA
Voltage
switch
PCA9532
Dimmer &
Blinker
16
2.3 V 5.5 V
2.1 µA
Voltage
switch
25 mA
5V
Open Drain
(Sink)
PCA9632
Dimmer &
Blinker
4
2.3 V 5.5 V
0.005 µA
Voltage
switch
-10 mA
25 mA
5V
Push Pull
(Configurable)
PCA9633
Dimmer &
Blinker
4
2.3 V 5.5 V
3.8 µA
Voltage
switch
-10 mA
25 mA
5V
Push Pull
(Configurable)
N
4+1
256
256
Y
Y
Y
N
N
N
I2C, Fm+
1, 4,
126
PCA9634
Dimmer &
Blinker
8
2.3 V 5.5 V
3.8 µA
Voltage
switch
-10 mA
25 mA
5V
Push Pull
(Configurable)
N
8+1
256
256
Y
Y
Y
N
N
N
I2C, Fm+
126
PCA9635
Dimmer &
Blinker
16
2.3 V 5.5 V
3.8 µA
Voltage
switch
-10 mA
25 mA
5V
Push Pull
(Configurable)
N
16 + 1
256
256
Y
Y
Y
N
N
N
I2C, Fm+
-10 mA
25 mA
2
2
2
126
Dimmer
16
2.3 V 5.5 V
2.2 µA
Voltage
switch
5V
Push Pull
(Configurable)
N
16
4096
N/A
Y
N
Y
Y
N
N
I C, Fm+
62
N
24 Hz 1526 Hz
N/A
In Production
PCA9624
Dimmer &
Blinker
8
2.3 V 5.5 V
2.1 µA
Voltage
switch
100 mA
40 V
Open Drain
(Sink)
N
8+1
256
256
Y
Y
Y
N
N
N
I2C, Fm+
126
N
97 KHz
190 Hz
(97 KHz)
In Production
PCA9622
Dimmer &
Blinker
16
2.3 V 5.5 V
3.2 µA
Voltage
switch
100 mA
40 V
Open Drain
(Sink)
N
16 + 1
256
256
Y
Y
Y
N
N
N
I2C, Fm+
126
N
97 KHz
190 Hz
(97 KHz)
In Production
PCA9626
Dimmer &
Blinker
24
2.3 V 5.5 V
6.0 µA
Voltage
switch
100 mA
40 V
Open Drain
(Sink)
N
24 + 1
256
256
Y
Y
Y
N
N
N
I2
C, Fm+
126
N
97 KHz
190 Hz
(97 KHz)
In Production
PCA9952[4]
Dimmer &
Blinker
16
3.0 V 5.5 V
100 µA
Constant
Current
57 mA
40 V
Open Drain
(Sink)
N
16 + 1
256
256
Y
Y
Y
Y
Y
Y
I2C, Fm+
8
Y
31.5 KHz
122 Hz
In Production
PCA9955[4]
Dimmer &
Blinker
16
3.0 V 5.5 V
100 µA
Constant
Current
57 mA
40 V
Open Drain
(Sink)
N
16 + 1
256
256
Y
Y
N
Y
Y
Y
I2C, Fm+
16
Y
31.5 KHz
122 Hz
In Production
PCA9955A
Dimmer &
Blinker
16
3.0 V5.5 V-
170 µA
Constant
Current
57 mA
20 V
Open Drain
(Sink)
N
16 + 1
256
256
Y
Y
Y
Y
Y
Y
I C, Fm+
125
Y
31.5 KHz
122 Hz
In Production
PCA9956A
Dimmer &
Blinker
24
3.0 V5.5 V
100 µA
Constant
Current
57 mA
20 V
Open Drain
(Sink)
N
24 + 1
256
256
Y
Y
Y
Y
Y
Y
I2C, Fm+
125
Y
31.5 KHz
122 Hz
In Production
PCA9655A
Dimmer &
Blinker
16
3.0 V5.5 V
170 µA
Voltage
switch
100 mA
20 V
Open Drain
(Sink)
N
16 + 1
256
256
Y
Y
Y
Y
N
Y
I2C, Fm+
125
Y
31.5 KHz
122 Hz
In Production
(Q3, 2014)
PCA9755A[3]
Dimmer &
Blinker
16
3.0 V5.5 V
100 µA
Constant
Current
57 mA
20 V
Open Drain
(Sink)
N
16 + 1
256
256
Y
Y
Y
Y
N
Y
SPI
25 MHz
25
Y
31.5 KHz
122 Hz
In Development
PCU9955A[3]
Dimmer &
Blinker
16
3.0 V 5.5 V
170 µA
Constant
Current
20 V
Open Drain
(Sink)
N
16 + 1
256
256
Y
Y
Y
Y
N
Y
I2C, UFm
125
Y
31.5 KHz
122 Hz
In Production
PCU9956A
Dimmer &
Blinker
24
3.0 V 5.5 V
100 µA
Constant
Current
20 V
Open Drain
(Sink)
N
24 + 1
256
256
Y
Y
Y
Y
N
Y
I C, UFm
125
Y
31.5 KHz
122 Hz
In Production
PCA9685
[2]
[3]
57 mA
57 mA
2
2
2
Typical value measured with VDD = 5.5 V, no load, VI = VDD or VSS and FSCL = 0 Hz
[2]
External clock input option
[3]
Build in Gradation control
[4]
In Production AEC-Q100 compliant version only
[1]
LED Flash Drivers Selection Guide
Assist Light
2.0 MHz
Y
Y
I2C, Fm or direct
1
820 ms
Y
Status
Max Timed Flash Operation
10 mA
Number of Device Addresses
160 mA
Interface Type
400 mA
Inductor Broken Coil Detect
500 mA
Indicator
Output
Integrated Diodes and Resistors
1 or 2
Touch
Fixed Switching Frequency
High-side drive
Flash (2 LEDs)
Flash LEDs Driven in Series
2.5 V - 5.5 V
Flash (1 LED)
Flash LED Output Drive Type
Synchronous
boost converter
Operating Voltage Range
SSL3252
Function
Device
Maximum LED Drive Current
In Production
PCA9622 Voltage Switch LED Driver Application Example
PCA9955A Constant Current LED driver Application Example
Architectural Lighting
Automotive Instrument Cluster
Mobile Phone Application Example
Car Radio Backlight
Application Support
For added application support, NXP offers the following application reports on the LED driver family devices:
} AN10579:
Driving LED light bars using NXP Solutions
http://www.nxp.com/documents/application_note/AN10579.pdf
} AN10733:
Flash LED App. Note
http://www.nxp.com/documents/application_note/AN10733.pdf
} AN264:
I2C Devices for LED Display Control App. Note
http://www.nxp.com/documents/application_note/AN264.pdf
} AN10315:
LED Dimmer Board
http://www.nxp.com/documents/application_note/AN10315.pdf
For more information, visit http://ics.nxp.com/products/led.drivers/
NXP offers evaluation modules and demo boards that can be used to develop software and evaluate the performance
of the LED controllers and LED Flash drivers.
OM6275 – I2C 2005-1 Evaluation Board
Easy experimentation and training module. I2C-bus connects
to LED controllers, other I2C peripherals, and daughter cards.
USB Connection. GUI interface allows direct control of device
without programming.
OM6276 – PCA9633 Demo Board
Evaluate LED dimming and blinking features of the PCA9633
4-bit (RGBA) PWM LED driver. RJ-45 jack allows series
connection to multiple boards to evaluate long-distance Fm+
bus and P82B96.
OM6279 – LED Dimmer Demo Board
NXP LED controllers and GPIO in simulated mobile phone
application showing RGB LED color mixing, LED blinking and
dimming, and backlight LED control applications.
OM6281 – PCA9698 Daughter Card for I2C 2005-1
PCA9698 40-bit GPIO with easy access to all 40 I/O pins
and several LEDs. Demonstrates using PCA9530 2-bit LED
dimmer to dim and/or blink all 40 outputs using the /OE input
of the PCA9698.
OM13483 – PCA9955A 16 channels LED demo board
The OM13483 is an add-on to 9-pin connector of NXP’s I2C
OM13321 – PCA9956A 24 channels LED demo board
The OM13321 is an add-on to 9-pin connector of NXP’s I2C
demo board 2005-1 or Fm+ I2C Bus development board.
This daughter board makes it easy to test and design with
the PCA9956A, a 24-channel Fast-mode Plus (Fm+) 57 mA
constant current and outputs allow up to 20 V for LED supply.
demo board 2005-1 or Fm+ I2C Bus development board.
This daughter board makes it easy to test and design with
the PCA9955A, a 16-channel Fast-mode Plus (Fm+) 57 mA
constant current and outputs allow up to 20 V for LED supply.
www.nxp.com/interface
© 2014 NXP B.V.
All rights reserved. Reproduction in whole or in part is prohibited without the prior written consent of the
copyright owner. The information presented in this document does not form part of any quotation or contract,
is believed to be accurate and reliable and may be changed without notice. No liability will be accepted by
the publisher for any consequence of its use. Publication thereof does not convey nor imply any license under
patent- or other industrial or intellectual property rights.
Date of release: June 2014
Document order number: 9397 750 17588
Printed in the Netherlands