Datasheet AP1042 (Asahi Kasei Microdevices) - 10

[AP1042]
9.2. PWM Duty Control
It is possible to control the PWM duty of the OUT pins by the voltage (DC) input to the VREF pin. With this function, the output current can be adjusted according to the VREF pin voltage. On-duty can be calculated by the following formula. PWM Duty = {VREF×(1-0.025) / (VDC×0.8) }+0.025 [%] For example, PWM duty will be 50% if VREF = 1.75 V. When VREF is 3.6 V or more, the PWM duty will be 100%. The switching frequency of PWM duty is determined internally and fixed to 44 kHz. The AP1042 operates in Break mode while the PWM duty mode is off. In order to maintain the accuracy of the PWM-duty control by the VREF pin, INA pin and INB pin should be fixed. Figure 8. Timing Chart of PWM-Duty Control 019002353-E-00 2019/03 - 10 - Document Outline 1. General Description 2. Features 3. Table of Contents 4. Block Diagram 5. Pin Configulations and Functions 5.1. Pin Layout 5.2. Pin Functions 6. Absolute Maximum Ratings 7. Recommended Operation Conditions 8. Electric Characteristics 9. Functional Descriptions 9.1. Control Logic 9.2. PWM Duty Control 9.3. Protection Functions 10. Recommended External Circuit 11. Package 11.1. Outline Dimensions 11.2. Land Pattern 11.3. Marking 12. Ordering Guide 13. Revision History IMPORTANT NOTICE