PCA9922

General description

The PCA9922 is an 8-channel constant current LED driver designed for LED signage and display applications. The output current is adjustable from 15 mA to 60 mA controlled by an external series resistor. The outputs are controlled via a serial interface with a maximum clock frequency of 25 MHz to allow for the system requirement of high volume data transmission. Each of the 8 channel outputs has edge rate control to limit the change in current when the outputs are enabled or disabled.

The device has built-in circuitry for detecting LED open-circuit and output short to ground. After signaling the specified error detect sequence on the input control lines, error status can be read out of the device via the serial data out.

The device is designed such that it may be cascaded with other similar devices. The SDO pin contains the output of the shift register which may be used for cascading to the SDI pin of the next device in the series. SDO changes state on the falling edge of CLK. SDI captures data on the rising edge of CLK.

The PCA9922 is a pin-to-pin functionally equivalent 5 V alternative (exception: error data is inverted; see Section 7.2.1, Section 7.2.2 and Section 7.2.7) for the ST2221A and STP08CDC596.

The PCA9922 is available in DIP16, TSSOP16 and HVQFN20 packages and is specified over the -40 Cel to +85 Cel industrial temperature range.

Features

• 25 MHz serial interface
• 3.3 V to 5.5 V operation
• 8 LED low side constant current outputs
• Global control for the 8 LED outputs variable between 15 mA to 60 mA
• 15 mA to 60 mA maximum current for all 8 output channels set by an external resistor
• Constant current matching at 25 Cel, V_DD = 5.0 V
• Bit-to-bit: +-6 pct
• Chip-to-chip: +-10 pct
• Gradual turn-on/turn-off output to limit EMI
• Error detection mode for line open, output short to ground, LED open and LED short
• -40 Cel to +85 Cel operation
• ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115, and 1000 V CDM per JESD22-C101
• Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
• Packages offered: DIP16, TSSOP16, HVQFN20

Products/packages

Quality/reliability/chemical content

Quality and reliability disclaimer

Pricing/ordering/availability

Applications

• Full color, multi-color, monochrome LED signs
• LED billboard displays
• Traffic display signs
• Transportation and commercial LED signs

Related applications
Intelligent washing machine
Intelligent washing machine
PCI analog/DVB-T stereo TV receiver
Transceiver board
Transceiver board
Power amplifier board
Main CPU board
Set-top box - MMS functionality
Color mixing for RGBA LEDs

Block diagrams/pinning

Design support

Application Notes

AN10145; AN10145 Bi-directional low voltage translators (2004-08-11)

AN10441; Level shifting techniques in I2C-bus design (2007-06-20)

Support Documents

UM10206; I2C Demonstration Board 2005-1 Quick Start Guide (2006-06-13)

UM10204; I2C-bus specification and user manual (2007-06-26)

web; IBIS and HSPICE Model ()

UM10317; PCA9633 demonstration board OM6282 (2008-12-15)

Print / Email

• Print this information
• Email this information

Disclaimers

• General product disclaimer
• Quality and reliability disclaimer