NXP Semiconductors PCA9952 16チャンネルFm+ I2Cバス57mA定電流LEDドライバー
NXP PCA9952 16チャンネルFm+ I2Cバス57mA定電流LEDドライバーは、アミューズメント製品用の57mA赤/緑/青/アンバー(RGBA)LEDの調光や点滅を最適化します。それぞれのLEDn出力が、31.25kHzで動作する8ビット分解能(256ステップ)固定周波数の専用PWMコントローラーを提供し、デューティ サイクルを0%～99.6%の範囲で調整できます。これにより、LEDを特定の輝度値に設定することが可能です。もうひとつの8ビット分解能(256ステップ)グループPWMコントローラーは122Hzの固定周波数、または15Hzから16.8秒に1回までの可変周波数で使用できるほか、デューティ サイクルを0%から99.6%まで調整可能で、すべてのLEDを同じ値で調光したり点滅させたりすることができます。
The PCA9952 has a Fast-mode Plus (Fm+) I2C-bus interface. Fm+ devices offer higher frequency (up to 1MHz) or more densely populated bus operation (up to 4000pF).
The PCA9952 is identical to PCA9955 except for the following differences:
- The PCA9952 has only three hardware address pins compared to four on PCA9955
- The PCA9952 has an output enable pin (OE) and the PCA9955 does not
The active LOW output enable input pin (OE), available only on PCA9952, blinks all the LEDn outputs and can be used to externally PWM the outputs, which is useful when multiple devices need to be dimmed or blinked together without using software control.
These devices have built-in open, short load and overtemperature detection circuitry. The error information from the corresponding register can be read via the I2C-bus. Additionally,na thermal shutdown feature protects the device when internal junction temperature exceeds the limit allowed for the process.
特徴
- 16 LED drivers. Each output programmable at:
- Off
- On
- Programmable LED brightness
- Programmable group dimming/blinking mixed with individual LED brightness
- Programmable LEDn output enable delay to reduce EMI and surge currents
- 16 constant current output channels can sink up to 57mA, tolerate up to 40V when OFF
- Output current accuracy
- 6% between output channels
- 8% between PCA9952/55 devices
- Open/short load/overtemperature detection mode to detect individual LED errors
- 1MHz Fast-mode Plus compatible I2C-bus interface with 30mA high drive capability on SDA output for driving high capacitive buses
- 256-step (8-bit) linear programmable brightness per LEDn output varying from fully off (default) to maximum brightness using a 31.25kHz PWM signal
- 256-step group brightness control allows general dimming (using a 122Hz PWM signal) from fully off to maximum brightness (default)
- 256-step group blinking with frequency programmable from 15Hz to 16.8s and duty cycle from 0% to 99.6%
- Output state change programmable on the Acknowledge or the STOP Command to update outputs byte-by-byte or all at the same time (default to 'Change on STOP')
アプリケーション
- RGB or RGBA LED drivers
- LED status information
- LED displays
- LCD backlights
- Keypad backlights for handheld devices
- Automotive lighting
Related Products
NXP Semiconductors PCA9955 16-channel Constant Current LED Driver
I2C-bus controlled driver optimized for dimming & blinking 57mA Red/Green/Blue/Amber (RGBA) LEDs.
Block Diagram
Pin Designations
