ZHCSNJ2D July 2006 – March 2021 PCA9554
PRODUCTION DATA
- 1 特性
- 2 說(shuō)明
- 3 Revision History
- 4 Description (Continued)
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Parameter Measurement Information
- 8 Detailed Description
- 9 Application Information Disclaimer
- 10Power Supply Recommendations
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
封裝選項(xiàng)
機(jī)械數(shù)據(jù) (封裝 | 引腳)
散熱焊盤(pán)機(jī)械數(shù)據(jù) (封裝 | 引腳)
訂購(gòu)信息
9.1.1.1.1 Minimizing ICC When I/Os Control Leds
When the I/Os are used to control LEDs, they are normally connected to VCC through a resistor as shown in Figure 9-1. The LED acts as a diode, so when the LED is off, the I/O VIN is about 1.2 V less than VCC. ΔICC in Electrical Characteristics shows how ICC increases as VIN becomes lower than VCC.
For battery-powered applications, it is essential that the voltage of I/O pins is greater than or equal to VCC when the LED is off to minimize current consumption. Figure 9-2 shows a high-value resistor in parallel with the LED. Figure 9-3 shows VCC less than the LED supply voltage by at least 1.2 V. Both of these methods maintain the I/O VIN at or above VCC and prevent additional supply-current consumption when the LED is off.
Figure 9-2 High-Value Resistor In Parallel With Led
Figure 9-3 Device Supplied By A Lower Voltage